Pezo, Milada L.

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Authority KeyName Variants
orcid::0000-0003-3285-0520
  • Pezo, Milada L. (22)
  • Pezo, Milada (1)
Projects

Author's Bibliography

Experimental and computational study of the two-fluid nozzle spreading characteristics

Pezo, Milada L.; Pezo, Lato; Dragojlović, Danka; Čolović, Radmilo; Čolović, Dušica; Vidosavljević, Strahinja; Hadnađev, Miroslav; Đuragić, Olivera

(2021)

TY  - JOUR
AU  - Pezo, Milada L.
AU  - Pezo, Lato
AU  - Dragojlović, Danka
AU  - Čolović, Radmilo
AU  - Čolović, Dušica
AU  - Vidosavljević, Strahinja
AU  - Hadnađev, Miroslav
AU  - Đuragić, Olivera
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8921
AB  - Spray nozzles are widely used in processing industry for spreading evenly large amount of fluids. The expansion of fluid depends on the nozzle type, the parameters of the nozzle and the characteristics of the working fluids. The experiments were performed for five fluid types used in food/pharma/animal feed application (glycerol, soybean oil, molasses, hydroxypropyl methylcellulose, tara gum), three diameters of the nozzle (1 mm, 3 mm, 5 mm) and three fluid temperatures (40 °C, 50 °C and 60 °C). An experimentally validated numerical model was developed, based on laminar two-phase flow, investigating different liquids, assuming the ideal gas flow, applying the finite volume method and volume of the fluid model with interface tracking. The effects of liquid parameters, nozzle diameter and liquid temperature on the characteristics of the jet were also analysed by artificial neural network model. The nozzle diameter strongly influenced the spreading characteristics of the jet, while the temperature affected the liquid viscosity. The increase of the temperature also led to the augment of the spreading angle of the fluid passing from the nozzle and also the enhancement of the spaying liquid expansion. © 2020 Institution of Chemical Engineers
T2  - Chemical Engineering Research and Design
T1  - Experimental and computational study of the two-fluid nozzle spreading characteristics
VL  - 166
SP  - 18
EP  - 28
DO  - 10.1016/j.cherd.2020.11.027
ER  - 
@article{
author = "Pezo, Milada L. and Pezo, Lato and Dragojlović, Danka and Čolović, Radmilo and Čolović, Dušica and Vidosavljević, Strahinja and Hadnađev, Miroslav and Đuragić, Olivera",
year = "2021",
url = "https://vinar.vin.bg.ac.rs/handle/123456789/8921",
abstract = "Spray nozzles are widely used in processing industry for spreading evenly large amount of fluids. The expansion of fluid depends on the nozzle type, the parameters of the nozzle and the characteristics of the working fluids. The experiments were performed for five fluid types used in food/pharma/animal feed application (glycerol, soybean oil, molasses, hydroxypropyl methylcellulose, tara gum), three diameters of the nozzle (1 mm, 3 mm, 5 mm) and three fluid temperatures (40 °C, 50 °C and 60 °C). An experimentally validated numerical model was developed, based on laminar two-phase flow, investigating different liquids, assuming the ideal gas flow, applying the finite volume method and volume of the fluid model with interface tracking. The effects of liquid parameters, nozzle diameter and liquid temperature on the characteristics of the jet were also analysed by artificial neural network model. The nozzle diameter strongly influenced the spreading characteristics of the jet, while the temperature affected the liquid viscosity. The increase of the temperature also led to the augment of the spreading angle of the fluid passing from the nozzle and also the enhancement of the spaying liquid expansion. © 2020 Institution of Chemical Engineers",
journal = "Chemical Engineering Research and Design",
title = "Experimental and computational study of the two-fluid nozzle spreading characteristics",
volume = "166",
pages = "18-28",
doi = "10.1016/j.cherd.2020.11.027"
}
Pezo, M. L., Pezo, L., Dragojlović, D., Čolović, R., Čolović, D., Vidosavljević, S., Hadnađev, M.,& Đuragić, O. (2021). Experimental and computational study of the two-fluid nozzle spreading characteristics.
Chemical Engineering Research and Design, 166, 18-28.
https://doi.org/10.1016/j.cherd.2020.11.027
Pezo ML, Pezo L, Dragojlović D, Čolović R, Čolović D, Vidosavljević S, Hadnađev M, Đuragić O. Experimental and computational study of the two-fluid nozzle spreading characteristics. Chemical Engineering Research and Design. 2021;166:18-28
Pezo Milada L., Pezo Lato, Dragojlović Danka, Čolović Radmilo, Čolović Dušica, Vidosavljević Strahinja, Hadnađev Miroslav, Đuragić Olivera, "Experimental and computational study of the two-fluid nozzle spreading characteristics" Chemical Engineering Research and Design, 166 (2021):18-28,
https://doi.org/10.1016/j.cherd.2020.11.027 .
1

Blending performance of the coupled Ross static mixer and vertical feed mixer - Discrete element model approach

Pezo, Lato; Pezo, Milada L.; Banjac, Vojislav; Jovanović, Aca; Krulj, Jelena; Kojić, Jovana; Kojić, Predrag

(2020)

TY  - JOUR
AU  - Pezo, Lato
AU  - Pezo, Milada L.
AU  - Banjac, Vojislav
AU  - Jovanović, Aca
AU  - Krulj, Jelena
AU  - Kojić, Jovana
AU  - Kojić, Predrag
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9118
AB  - The mixing quality of the pigeon diet mix was studied after the mixing in the Ross-type static mixer (pre-mixer) and the vertical feed mixer (final mixer in the line). Three different experiments were performed: firstly, the possibilities of static mixer were investigated, secondly the blending performance of the vertical feed mixer, and the combination of these approaches in the third experiment. The Discrete Element Method was used in numerical modelling of granular flow in the pre-mixer and the vertical feed mixer, to predict the inter-particle mixing quality, and the results of the mixing. The results of the model were compared with appropriate experiments. The main goal was to foresee the behaviour of mixture in two type of mixers and to evaluate the combined mixing action of these two mixers, in order to explore the possibilities to increase the mixing quality, shorten the mixing time and to reduce the energy consumption.
T2  - Powder Technology
T1  - Blending performance of the coupled Ross static mixer and vertical feed mixer - Discrete element model approach
VL  - 375
SP  - 20
EP  - 27
DO  - 10.1016/j.powtec.2020.07.104
ER  - 
@article{
author = "Pezo, Lato and Pezo, Milada L. and Banjac, Vojislav and Jovanović, Aca and Krulj, Jelena and Kojić, Jovana and Kojić, Predrag",
year = "2020",
url = "https://vinar.vin.bg.ac.rs/handle/123456789/9118",
abstract = "The mixing quality of the pigeon diet mix was studied after the mixing in the Ross-type static mixer (pre-mixer) and the vertical feed mixer (final mixer in the line). Three different experiments were performed: firstly, the possibilities of static mixer were investigated, secondly the blending performance of the vertical feed mixer, and the combination of these approaches in the third experiment. The Discrete Element Method was used in numerical modelling of granular flow in the pre-mixer and the vertical feed mixer, to predict the inter-particle mixing quality, and the results of the mixing. The results of the model were compared with appropriate experiments. The main goal was to foresee the behaviour of mixture in two type of mixers and to evaluate the combined mixing action of these two mixers, in order to explore the possibilities to increase the mixing quality, shorten the mixing time and to reduce the energy consumption.",
journal = "Powder Technology",
title = "Blending performance of the coupled Ross static mixer and vertical feed mixer - Discrete element model approach",
volume = "375",
pages = "20-27",
doi = "10.1016/j.powtec.2020.07.104"
}
Pezo, L., Pezo, M. L., Banjac, V., Jovanović, A., Krulj, J., Kojić, J.,& Kojić, P. (2020). Blending performance of the coupled Ross static mixer and vertical feed mixer - Discrete element model approach.
Powder Technology, 375, 20-27.
https://doi.org/10.1016/j.powtec.2020.07.104
Pezo L, Pezo ML, Banjac V, Jovanović A, Krulj J, Kojić J, Kojić P. Blending performance of the coupled Ross static mixer and vertical feed mixer - Discrete element model approach. Powder Technology. 2020;375:20-27
Pezo Lato, Pezo Milada L., Banjac Vojislav, Jovanović Aca, Krulj Jelena, Kojić Jovana, Kojić Predrag, "Blending performance of the coupled Ross static mixer and vertical feed mixer - Discrete element model approach" Powder Technology, 375 (2020):20-27,
https://doi.org/10.1016/j.powtec.2020.07.104 .
1
1

Prediction model based on artificial neural network for pyrophyllite mechano-chemical activation as an integral step in production of cement binders

Terzić, Anja; Radulović, Dragan; Pezo, Milada; Stojanović, Jovica; Pezo, Lato; Radojević, Zagorka; Andrić, Ljubiša

(2020)

TY  - JOUR
AU  - Terzić, Anja
AU  - Radulović, Dragan
AU  - Pezo, Milada
AU  - Stojanović, Jovica
AU  - Pezo, Lato
AU  - Radojević, Zagorka
AU  - Andrić, Ljubiša
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9042
AB  - The optimal outputs of pyrophyllite mechano-chemical activation in an ultra-centrifugal mill performing under different technological conditions were determined by analytical modeling and verified via Artificial Neural Network in order to be employed in the production of cement-based binders. Cluster Analysis and Principal Component Analysis were utilized in assessment of the effect of activation process parameters on the activated pyrophyllite quality. Artificial Neural Network which performed with high prediction accuracy, i.e. 0.914 during the training period, was sufficient for precise prediction of activated pyrophyllite quality in a wide range of processing parameters. The probability of utilization of observed activation products was estimated through interrelation of technological parameters (mesh size sieve, activation period, specific energy consumption) and acquired characteristics of pyrophyllite (grain diameter, specific surface area). The optimal products singled out from each activation sequence were used as mineral additives in the mix-designs of four cement binders (cement replacement portion was 30%). Influence of activated pyrophyllite additions on the cement chemistry, mineral phase compositions and microstructures of the cement binders were monitored by instrumental techniques (DTA/TGA, XRD, SEM). Activated pyrophyllite showed characteristics of pozzolana as it slightly accelerated early stages of hydration, decreased cement hydration energy and increased the quantity of cement mineral alite at later hydration stages. Micron-sized crystalline foila characteristic for mechanically activated pyrophyllite formed micro-reinforcement within cement binder microstructure.
T2  - Construction and Building Materials
T1  - Prediction model based on artificial neural network for pyrophyllite mechano-chemical activation as an integral step in production of cement binders
VL  - 258
SP  - 119721
DO  - 10.1016/j.conbuildmat.2020.119721
ER  - 
@article{
author = "Terzić, Anja and Radulović, Dragan and Pezo, Milada and Stojanović, Jovica and Pezo, Lato and Radojević, Zagorka and Andrić, Ljubiša",
year = "2020",
url = "https://vinar.vin.bg.ac.rs/handle/123456789/9042",
abstract = "The optimal outputs of pyrophyllite mechano-chemical activation in an ultra-centrifugal mill performing under different technological conditions were determined by analytical modeling and verified via Artificial Neural Network in order to be employed in the production of cement-based binders. Cluster Analysis and Principal Component Analysis were utilized in assessment of the effect of activation process parameters on the activated pyrophyllite quality. Artificial Neural Network which performed with high prediction accuracy, i.e. 0.914 during the training period, was sufficient for precise prediction of activated pyrophyllite quality in a wide range of processing parameters. The probability of utilization of observed activation products was estimated through interrelation of technological parameters (mesh size sieve, activation period, specific energy consumption) and acquired characteristics of pyrophyllite (grain diameter, specific surface area). The optimal products singled out from each activation sequence were used as mineral additives in the mix-designs of four cement binders (cement replacement portion was 30%). Influence of activated pyrophyllite additions on the cement chemistry, mineral phase compositions and microstructures of the cement binders were monitored by instrumental techniques (DTA/TGA, XRD, SEM). Activated pyrophyllite showed characteristics of pozzolana as it slightly accelerated early stages of hydration, decreased cement hydration energy and increased the quantity of cement mineral alite at later hydration stages. Micron-sized crystalline foila characteristic for mechanically activated pyrophyllite formed micro-reinforcement within cement binder microstructure.",
journal = "Construction and Building Materials",
title = "Prediction model based on artificial neural network for pyrophyllite mechano-chemical activation as an integral step in production of cement binders",
volume = "258",
pages = "119721",
doi = "10.1016/j.conbuildmat.2020.119721"
}
Terzić, A., Radulović, D., Pezo, M., Stojanović, J., Pezo, L., Radojević, Z.,& Andrić, L. (2020). Prediction model based on artificial neural network for pyrophyllite mechano-chemical activation as an integral step in production of cement binders.
Construction and Building Materials, 258, 119721.
https://doi.org/10.1016/j.conbuildmat.2020.119721
Terzić A, Radulović D, Pezo M, Stojanović J, Pezo L, Radojević Z, Andrić L. Prediction model based on artificial neural network for pyrophyllite mechano-chemical activation as an integral step in production of cement binders. Construction and Building Materials. 2020;258:119721
Terzić Anja, Radulović Dragan, Pezo Milada, Stojanović Jovica, Pezo Lato, Radojević Zagorka, Andrić Ljubiša, "Prediction model based on artificial neural network for pyrophyllite mechano-chemical activation as an integral step in production of cement binders" Construction and Building Materials, 258 (2020):119721,
https://doi.org/10.1016/j.conbuildmat.2020.119721 .

Application of soybean oil and glycerol in animal feed production, ANN model

Dragojlović, Danka; Pezo, Lato; Čolović, Dušica; Vidosavljević, Strahinja; Pezo, Milada L.; Čolović, Radmilo; Kokić, Bojana; Đuragić, Olivera

(2019)

TY  - JOUR
AU  - Dragojlović, Danka
AU  - Pezo, Lato
AU  - Čolović, Dušica
AU  - Vidosavljević, Strahinja
AU  - Pezo, Milada L.
AU  - Čolović, Radmilo
AU  - Kokić, Bojana
AU  - Đuragić, Olivera
PY  - 2019
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8821
AB  - In the past few decades the diet preparation in feed production has evolved towards more complicated technological operations, which include different liquid addition. A wide scale of different liquids is used in contemporary animal feed production, from oils and glycerol to more expensive products in a liquid form, such as enzymes, flavourings, amino acids, vitamins and others. In the presented study the liquid addition in feed production was observed, with a specific goal to investigate the spraying systems in order to better understand the effects of fluids, such as soybean oil and glycerol, on feed production. The dispersion angles of spraying nozzle for glycerol and soybean oil were determined as an indicator of the uniform application of liquids during feed production. Dispersion of the material was accomplished using the two-fluid nozzle. The performance of Artificial Neural Network (ANN) was compared with experimental data in order to develop rapid and accurate method for prediction of dispersion angle. The ANN model showed high prediction accuracy (r2 = 0.945).
T2  - Acta Periodica Technologica
T1  - Application of soybean oil and glycerol in animal feed production, ANN model
IS  - 50
SP  - 51
EP  - 58
DO  - 10.2298/APT1950051D
ER  - 
@article{
author = "Dragojlović, Danka and Pezo, Lato and Čolović, Dušica and Vidosavljević, Strahinja and Pezo, Milada L. and Čolović, Radmilo and Kokić, Bojana and Đuragić, Olivera",
year = "2019",
url = "https://vinar.vin.bg.ac.rs/handle/123456789/8821",
abstract = "In the past few decades the diet preparation in feed production has evolved towards more complicated technological operations, which include different liquid addition. A wide scale of different liquids is used in contemporary animal feed production, from oils and glycerol to more expensive products in a liquid form, such as enzymes, flavourings, amino acids, vitamins and others. In the presented study the liquid addition in feed production was observed, with a specific goal to investigate the spraying systems in order to better understand the effects of fluids, such as soybean oil and glycerol, on feed production. The dispersion angles of spraying nozzle for glycerol and soybean oil were determined as an indicator of the uniform application of liquids during feed production. Dispersion of the material was accomplished using the two-fluid nozzle. The performance of Artificial Neural Network (ANN) was compared with experimental data in order to develop rapid and accurate method for prediction of dispersion angle. The ANN model showed high prediction accuracy (r2 = 0.945).",
journal = "Acta Periodica Technologica",
title = "Application of soybean oil and glycerol in animal feed production, ANN model",
number = "50",
pages = "51-58",
doi = "10.2298/APT1950051D"
}
Dragojlović, D., Pezo, L., Čolović, D., Vidosavljević, S., Pezo, M. L., Čolović, R., Kokić, B.,& Đuragić, O. (2019). Application of soybean oil and glycerol in animal feed production, ANN model.
Acta Periodica Technologica(50), 51-58.
https://doi.org/10.2298/APT1950051D
Dragojlović D, Pezo L, Čolović D, Vidosavljević S, Pezo ML, Čolović R, Kokić B, Đuragić O. Application of soybean oil and glycerol in animal feed production, ANN model. Acta Periodica Technologica. 2019;(50):51-58
Dragojlović Danka, Pezo Lato, Čolović Dušica, Vidosavljević Strahinja, Pezo Milada L., Čolović Radmilo, Kokić Bojana, Đuragić Olivera, "Application of soybean oil and glycerol in animal feed production, ANN model" Acta Periodica Technologica, no. 50 (2019):51-58,
https://doi.org/10.2298/APT1950051D .
1
1

The joint mixing action of the static pre-mixer and the rotating drum mixer – Discrete element method approach

Pezo, Lato; Pezo, Milada L.; Jovanović, Aca; Čolović, Radmilo; Vukmirović, Đuro; Banjac, Vojislav; Đuragić, Olivera

(2018)

TY  - JOUR
AU  - Pezo, Lato
AU  - Pezo, Milada L.
AU  - Jovanović, Aca
AU  - Čolović, Radmilo
AU  - Vukmirović, Đuro
AU  - Banjac, Vojislav
AU  - Đuragić, Olivera
PY  - 2018
UR  - http://linkinghub.elsevier.com/retrieve/pii/S092188311830147X
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/7673
AB  - In this study, the mixing performance of coupled mixing action of the Komax static mixer (which is used as a pre-mixer) and rotating drum (applied as the final mixer) was explored in the maize meal mixing operation. The main objective of this paper was to predict the behaviour of the previously grinded maize particles, during the mixing process in static mixer and drum mixer, and to explore the possibilities to shorten the mixing time in the main mixer (in order to reduce the energy consumption). Three different experiments were performed: in the first experiment, possibilities of static mixer were explored, second experiment showed the mixing performance of rotating drum, and the combination of these two mixing devices was investigated in the third experiment. Homogeneity of the obtained mixtures was determined experimentally, by the “Microtracers” method. The Discrete Element Method was used for modelling of granular flow in the pre-mixing and final mixing applications, and to predict the inter-particle mixing quality within a static mixer and the rotating drum mixer. The results of the numerical simulation are compared with appropriate experimental results. The possible industrial application of this model could be the optimization of parameters of mixing systems taking into account the quality and the duration of the mixing process.
T2  - Advanced Powder Technology
T1  - The joint mixing action of the static pre-mixer and the rotating drum mixer – Discrete element method approach
VL  - 29
IS  - 7
SP  - 1734
EP  - 1741
DO  - 10.1016/j.apt.2018.04.008
ER  - 
@article{
author = "Pezo, Lato and Pezo, Milada L. and Jovanović, Aca and Čolović, Radmilo and Vukmirović, Đuro and Banjac, Vojislav and Đuragić, Olivera",
year = "2018",
url = "http://linkinghub.elsevier.com/retrieve/pii/S092188311830147X, http://vinar.vin.bg.ac.rs/handle/123456789/7673",
abstract = "In this study, the mixing performance of coupled mixing action of the Komax static mixer (which is used as a pre-mixer) and rotating drum (applied as the final mixer) was explored in the maize meal mixing operation. The main objective of this paper was to predict the behaviour of the previously grinded maize particles, during the mixing process in static mixer and drum mixer, and to explore the possibilities to shorten the mixing time in the main mixer (in order to reduce the energy consumption). Three different experiments were performed: in the first experiment, possibilities of static mixer were explored, second experiment showed the mixing performance of rotating drum, and the combination of these two mixing devices was investigated in the third experiment. Homogeneity of the obtained mixtures was determined experimentally, by the “Microtracers” method. The Discrete Element Method was used for modelling of granular flow in the pre-mixing and final mixing applications, and to predict the inter-particle mixing quality within a static mixer and the rotating drum mixer. The results of the numerical simulation are compared with appropriate experimental results. The possible industrial application of this model could be the optimization of parameters of mixing systems taking into account the quality and the duration of the mixing process.",
journal = "Advanced Powder Technology",
title = "The joint mixing action of the static pre-mixer and the rotating drum mixer – Discrete element method approach",
volume = "29",
number = "7",
pages = "1734-1741",
doi = "10.1016/j.apt.2018.04.008"
}
Pezo, L., Pezo, M. L., Jovanović, A., Čolović, R., Vukmirović, Đ., Banjac, V.,& Đuragić, O. (2018). The joint mixing action of the static pre-mixer and the rotating drum mixer – Discrete element method approach.
Advanced Powder Technology, 29(7), 1734-1741.
https://doi.org/10.1016/j.apt.2018.04.008
Pezo L, Pezo ML, Jovanović A, Čolović R, Vukmirović Đ, Banjac V, Đuragić O. The joint mixing action of the static pre-mixer and the rotating drum mixer – Discrete element method approach. Advanced Powder Technology. 2018;29(7):1734-1741
Pezo Lato, Pezo Milada L., Jovanović Aca, Čolović Radmilo, Vukmirović Đuro, Banjac Vojislav, Đuragić Olivera, "The joint mixing action of the static pre-mixer and the rotating drum mixer – Discrete element method approach" Advanced Powder Technology, 29, no. 7 (2018):1734-1741,
https://doi.org/10.1016/j.apt.2018.04.008 .
7
3
6

Discrete element model of particle transport and premixing action in modified screw conveyors

Pezo, Milada L.; Pezo, Lato; Jovanović, Aca; Terzić, Anja; Andrić, Ljubiša; Lončar, Biljana; Kojić, Predrag S.

(2018)

TY  - JOUR
AU  - Pezo, Milada L.
AU  - Pezo, Lato
AU  - Jovanović, Aca
AU  - Terzić, Anja
AU  - Andrić, Ljubiša
AU  - Lončar, Biljana
AU  - Kojić, Predrag S.
PY  - 2018
UR  - https://linkinghub.elsevier.com/retrieve/pii/S0032591018304480
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/7719
AB  - In this paper, five types of horizontal single-pitch screw conveyors with modified geometry, with three different lengths (400, 600 and 800 mm) were investigated for transport and auxiliary mixing action of two materials: natural zeolite and quartz aggregate (sand) with particle sizes 3, 4 and 5 mm. The geometry of the screw transporter is changed by welding three additional helices oriented in the same or the opposite direction from screw cutting edges, enabling the premixing of materials, during the transport. The proper mixing of the observed materials provides an adequate disposition of zeolite particles within the composite and prevents agglomeration and interference with cement hydration. Zeolite application as a binder in a building material is a possible solution to environmental pollution problems caused by cement production. The influences of screw length, particle diameter, the studied geometry variations of screw design, on the mixing performances of the screw conveyor-mixer during material transport were explored. All investigations were performed experimentally and numerically, by using Discrete Element Method (DEM). The experimental results and the results of the DEM investigation were used for the development of mathematical models for the prediction of mixing quality, which are presented in the form of second order polynomial and artificial neural network model.
T2  - Powder Technology
T1  - Discrete element model of particle transport and premixing action in modified screw conveyors
VL  - 336
SP  - 255
EP  - 264
DO  - 10.1016/j.powtec.2018.06.009
ER  - 
@article{
author = "Pezo, Milada L. and Pezo, Lato and Jovanović, Aca and Terzić, Anja and Andrić, Ljubiša and Lončar, Biljana and Kojić, Predrag S.",
year = "2018",
url = "https://linkinghub.elsevier.com/retrieve/pii/S0032591018304480, http://vinar.vin.bg.ac.rs/handle/123456789/7719",
abstract = "In this paper, five types of horizontal single-pitch screw conveyors with modified geometry, with three different lengths (400, 600 and 800 mm) were investigated for transport and auxiliary mixing action of two materials: natural zeolite and quartz aggregate (sand) with particle sizes 3, 4 and 5 mm. The geometry of the screw transporter is changed by welding three additional helices oriented in the same or the opposite direction from screw cutting edges, enabling the premixing of materials, during the transport. The proper mixing of the observed materials provides an adequate disposition of zeolite particles within the composite and prevents agglomeration and interference with cement hydration. Zeolite application as a binder in a building material is a possible solution to environmental pollution problems caused by cement production. The influences of screw length, particle diameter, the studied geometry variations of screw design, on the mixing performances of the screw conveyor-mixer during material transport were explored. All investigations were performed experimentally and numerically, by using Discrete Element Method (DEM). The experimental results and the results of the DEM investigation were used for the development of mathematical models for the prediction of mixing quality, which are presented in the form of second order polynomial and artificial neural network model.",
journal = "Powder Technology",
title = "Discrete element model of particle transport and premixing action in modified screw conveyors",
volume = "336",
pages = "255-264",
doi = "10.1016/j.powtec.2018.06.009"
}
Pezo, M. L., Pezo, L., Jovanović, A., Terzić, A., Andrić, L., Lončar, B.,& Kojić, P. S. (2018). Discrete element model of particle transport and premixing action in modified screw conveyors.
Powder Technology, 336, 255-264.
https://doi.org/10.1016/j.powtec.2018.06.009
Pezo ML, Pezo L, Jovanović A, Terzić A, Andrić L, Lončar B, Kojić PS. Discrete element model of particle transport and premixing action in modified screw conveyors. Powder Technology. 2018;336:255-264
Pezo Milada L., Pezo Lato, Jovanović Aca, Terzić Anja, Andrić Ljubiša, Lončar Biljana, Kojić Predrag S., "Discrete element model of particle transport and premixing action in modified screw conveyors" Powder Technology, 336 (2018):255-264,
https://doi.org/10.1016/j.powtec.2018.06.009 .
7
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9

Optimization of the classification process in the zigzag air classifier for obtaining a high protein sunflower meal - Chemometric and CFD approach

Banjac, Vojislav; Pezo, Lato; Pezo, Milada L.; Vukmirović, Đuro; Colovic, Dusica; Fistes, Aleksandar; Čolović, Radmilo

(2017)

TY  - JOUR
AU  - Banjac, Vojislav
AU  - Pezo, Lato
AU  - Pezo, Milada L.
AU  - Vukmirović, Đuro
AU  - Colovic, Dusica
AU  - Fistes, Aleksandar
AU  - Čolović, Radmilo
PY  - 2017
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/1492
AB  - In this study, sunflower meal is ground by a hammer mill after which air zigzag gravitational air classifier is used for separating sunflower hulls from the kernels in order to obtain protein rich fractions. Three hammer mill sieves with sieve openings diameter of 3, 2 and 1 mm were used, while three air flows (5, 8.7 and 12.5 m(3)/h) and three feed rates (30%, 60% an 90% of bowl feeder oscillation maximum rate) were varied during air classification process. For describing the effects of the test variables on the observed responses Principal Component Analysis, Standard Score analysis and Response Surface Methodology were used. Beside experimental investigations, CFD model was used for numerical optimization of sunflower meal air classification process. Air classification of hammer milled sunflower meal resulted in coarse fractions enriched in protein content. The decrease in sieve openings diameter of the hammer mill sieve increased protein content in coarse fractions of sunflower meal obtained at same air flow, and at the same time decreased matching fraction yield. Increase in air flow lead to the increase in protein content along the same hammer mill sieve. Standard score analysis showed that optimum values for protein content and ratio of coarse and fine fractions have been obtained by using a sieve with 1 mm opening diameter, air flow of 12.5 m(3)/h and 60% of the maximum feeder rate. Fraction ratio and protein content were mostly affected by the linear term of air flow and the sieve openings diameter of the hammer mill sieve in the Second Order Polynomial model. The main focus of CFD analysis was on the particle simulation and the evaluation of the separation efficiency of the zigzag classifier. (C) 2017 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.
T2  - Advanced Powder Technology
T1  - Optimization of the classification process in the zigzag air classifier for obtaining a high protein sunflower meal - Chemometric and CFD approach
VL  - 28
IS  - 3
SP  - 1069
EP  - 1078
DO  - 10.1016/j.apt.2017.01.013
ER  - 
@article{
author = "Banjac, Vojislav and Pezo, Lato and Pezo, Milada L. and Vukmirović, Đuro and Colovic, Dusica and Fistes, Aleksandar and Čolović, Radmilo",
year = "2017",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/1492",
abstract = "In this study, sunflower meal is ground by a hammer mill after which air zigzag gravitational air classifier is used for separating sunflower hulls from the kernels in order to obtain protein rich fractions. Three hammer mill sieves with sieve openings diameter of 3, 2 and 1 mm were used, while three air flows (5, 8.7 and 12.5 m(3)/h) and three feed rates (30%, 60% an 90% of bowl feeder oscillation maximum rate) were varied during air classification process. For describing the effects of the test variables on the observed responses Principal Component Analysis, Standard Score analysis and Response Surface Methodology were used. Beside experimental investigations, CFD model was used for numerical optimization of sunflower meal air classification process. Air classification of hammer milled sunflower meal resulted in coarse fractions enriched in protein content. The decrease in sieve openings diameter of the hammer mill sieve increased protein content in coarse fractions of sunflower meal obtained at same air flow, and at the same time decreased matching fraction yield. Increase in air flow lead to the increase in protein content along the same hammer mill sieve. Standard score analysis showed that optimum values for protein content and ratio of coarse and fine fractions have been obtained by using a sieve with 1 mm opening diameter, air flow of 12.5 m(3)/h and 60% of the maximum feeder rate. Fraction ratio and protein content were mostly affected by the linear term of air flow and the sieve openings diameter of the hammer mill sieve in the Second Order Polynomial model. The main focus of CFD analysis was on the particle simulation and the evaluation of the separation efficiency of the zigzag classifier. (C) 2017 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.",
journal = "Advanced Powder Technology",
title = "Optimization of the classification process in the zigzag air classifier for obtaining a high protein sunflower meal - Chemometric and CFD approach",
volume = "28",
number = "3",
pages = "1069-1078",
doi = "10.1016/j.apt.2017.01.013"
}
Banjac, V., Pezo, L., Pezo, M. L., Vukmirović, Đ., Colovic, D., Fistes, A.,& Čolović, R. (2017). Optimization of the classification process in the zigzag air classifier for obtaining a high protein sunflower meal - Chemometric and CFD approach.
Advanced Powder Technology, 28(3), 1069-1078.
https://doi.org/10.1016/j.apt.2017.01.013
Banjac V, Pezo L, Pezo ML, Vukmirović Đ, Colovic D, Fistes A, Čolović R. Optimization of the classification process in the zigzag air classifier for obtaining a high protein sunflower meal - Chemometric and CFD approach. Advanced Powder Technology. 2017;28(3):1069-1078
Banjac Vojislav, Pezo Lato, Pezo Milada L., Vukmirović Đuro, Colovic Dusica, Fistes Aleksandar, Čolović Radmilo, "Optimization of the classification process in the zigzag air classifier for obtaining a high protein sunflower meal - Chemometric and CFD approach" Advanced Powder Technology, 28, no. 3 (2017):1069-1078,
https://doi.org/10.1016/j.apt.2017.01.013 .
10
7
8

DEM/CFD approach for modeling granular flow in the revolving static mixer

Pezo, Milada L.; Pezo, Lato; Jovanović, Aca; Lončar, Biljana; Čolović, Radmilo

(2016)

TY  - JOUR
AU  - Pezo, Milada L.
AU  - Pezo, Lato
AU  - Jovanović, Aca
AU  - Lončar, Biljana
AU  - Čolović, Radmilo
PY  - 2016
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/1090
AB  - DEM/CFD (Discrete Element Method/Computational Fluid Dynamic) approach was used to develop a three dimensional model of fluid flow and mixing process of solid particles within the revolving static mixer, type Komax. Static mixers are widely used in process industry, food industry, pharmaceutical and chemical industry. Mixing process adds significant value to the final product and it can be regarded as a key process. The quality and the price of the product often depend on mixing efficiency. Both design and operation of the mixing unit itself have a strong influence on the quality produced. In this paper, DEM is used for modeling granular flow of zeolite spheres in the revolving Komax static mixer and CFD method was used for modeling fluid flow through the Eulerian multiphase model. Coupling of these two methods provides reliable analysis of particle motion and flow pattern of the working fluid. The objective of this paper is to predict the behavior of particles after several rotations of the revolving static mixer. This type of device is used for premixing action before the main mixing process, for significant reduction of mixing time and energy consumption. This type of premixing action is not investigated in detail in the open literature. The results of the numerical simulation are compared with appropriate experimental results. The special design revolving static mixer, made of transparent Plexiglas was used for this experiment. Mixing quality was examined by RSD (relative standard deviation) criterion. Application of this model provides the optimization of the number of revolutions and geometrical parameters of mixing process taking into account the quality of the mixing process. (c) 2016 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
T2  - Chemical Engineering Research and Design
T1  - DEM/CFD approach for modeling granular flow in the revolving static mixer
VL  - 109
SP  - 317
EP  - 326
DO  - 10.1016/j.cherd.2016.02.003
ER  - 
@article{
author = "Pezo, Milada L. and Pezo, Lato and Jovanović, Aca and Lončar, Biljana and Čolović, Radmilo",
year = "2016",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/1090",
abstract = "DEM/CFD (Discrete Element Method/Computational Fluid Dynamic) approach was used to develop a three dimensional model of fluid flow and mixing process of solid particles within the revolving static mixer, type Komax. Static mixers are widely used in process industry, food industry, pharmaceutical and chemical industry. Mixing process adds significant value to the final product and it can be regarded as a key process. The quality and the price of the product often depend on mixing efficiency. Both design and operation of the mixing unit itself have a strong influence on the quality produced. In this paper, DEM is used for modeling granular flow of zeolite spheres in the revolving Komax static mixer and CFD method was used for modeling fluid flow through the Eulerian multiphase model. Coupling of these two methods provides reliable analysis of particle motion and flow pattern of the working fluid. The objective of this paper is to predict the behavior of particles after several rotations of the revolving static mixer. This type of device is used for premixing action before the main mixing process, for significant reduction of mixing time and energy consumption. This type of premixing action is not investigated in detail in the open literature. The results of the numerical simulation are compared with appropriate experimental results. The special design revolving static mixer, made of transparent Plexiglas was used for this experiment. Mixing quality was examined by RSD (relative standard deviation) criterion. Application of this model provides the optimization of the number of revolutions and geometrical parameters of mixing process taking into account the quality of the mixing process. (c) 2016 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.",
journal = "Chemical Engineering Research and Design",
title = "DEM/CFD approach for modeling granular flow in the revolving static mixer",
volume = "109",
pages = "317-326",
doi = "10.1016/j.cherd.2016.02.003"
}
Pezo, M. L., Pezo, L., Jovanović, A., Lončar, B.,& Čolović, R. (2016). DEM/CFD approach for modeling granular flow in the revolving static mixer.
Chemical Engineering Research and Design, 109, 317-326.
https://doi.org/10.1016/j.cherd.2016.02.003
Pezo ML, Pezo L, Jovanović A, Lončar B, Čolović R. DEM/CFD approach for modeling granular flow in the revolving static mixer. Chemical Engineering Research and Design. 2016;109:317-326
Pezo Milada L., Pezo Lato, Jovanović Aca, Lončar Biljana, Čolović Radmilo, "DEM/CFD approach for modeling granular flow in the revolving static mixer" Chemical Engineering Research and Design, 109 (2016):317-326,
https://doi.org/10.1016/j.cherd.2016.02.003 .
11
12
13

Granular flow in static mixers by coupled DEM/CFD approach

Pezo, Lato; Pezo, Milada L.; Jovanović, Aca; Kosanic, Nenad; Petrović, Aleksandar Lj.; Levic, Ljubinko

(2016)

TY  - JOUR
AU  - Pezo, Lato
AU  - Pezo, Milada L.
AU  - Jovanović, Aca
AU  - Kosanic, Nenad
AU  - Petrović, Aleksandar Lj.
AU  - Levic, Ljubinko
PY  - 2016
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/1307
AB  - The mixing process greatly influences the mixing efficiency, as well as the quality and the price of the intermediate and/or the final product. Static mixer is used for premixing action before the main mixing process, for significant reduction of mixing time and energy consumption. This type of premixing action is not investigated in detail in the open literature. In this article, the novel numerical approach called Discrete Element Method is used for modelling of granular flow in multiple static mixer applications (1-3 Komax or Ross mixing elements were utilized), while the Computational Fluid Dynamic Method was chosen for fluid flow modelling, using the Eulerian multiphase model. The main aim of this article is to predict the behavior of granules being gravitationally transported in different mixer configuration and to choose the best configuration of the mixer taking into account the total particle path, the number of mixing elements and the quality of the obtained mixture. The results of the numerical simulations in the static mixers were compared to experimental results, the mixing quality is examined by RSD (relative standard deviation) criterion, and the effects on the mixer type and the number of mixing elements on mixing process were studied. The effects of the mixer type and the number of mixing elements on mixing process were studied using analysis of variance (ANOVA). Mathematical modelling is used for optimization of number of Ross and Komax segments in mixer in order to gain desirable mixing results.
T2  - Hemijska industrija
T1  - Granular flow in static mixers by coupled DEM/CFD approach
VL  - 70
IS  - 5
SP  - 539
EP  - 546
DO  - 10.2298/HEMIND151013060P
ER  - 
@article{
author = "Pezo, Lato and Pezo, Milada L. and Jovanović, Aca and Kosanic, Nenad and Petrović, Aleksandar Lj. and Levic, Ljubinko",
year = "2016",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/1307",
abstract = "The mixing process greatly influences the mixing efficiency, as well as the quality and the price of the intermediate and/or the final product. Static mixer is used for premixing action before the main mixing process, for significant reduction of mixing time and energy consumption. This type of premixing action is not investigated in detail in the open literature. In this article, the novel numerical approach called Discrete Element Method is used for modelling of granular flow in multiple static mixer applications (1-3 Komax or Ross mixing elements were utilized), while the Computational Fluid Dynamic Method was chosen for fluid flow modelling, using the Eulerian multiphase model. The main aim of this article is to predict the behavior of granules being gravitationally transported in different mixer configuration and to choose the best configuration of the mixer taking into account the total particle path, the number of mixing elements and the quality of the obtained mixture. The results of the numerical simulations in the static mixers were compared to experimental results, the mixing quality is examined by RSD (relative standard deviation) criterion, and the effects on the mixer type and the number of mixing elements on mixing process were studied. The effects of the mixer type and the number of mixing elements on mixing process were studied using analysis of variance (ANOVA). Mathematical modelling is used for optimization of number of Ross and Komax segments in mixer in order to gain desirable mixing results.",
journal = "Hemijska industrija",
title = "Granular flow in static mixers by coupled DEM/CFD approach",
volume = "70",
number = "5",
pages = "539-546",
doi = "10.2298/HEMIND151013060P"
}
Pezo, L., Pezo, M. L., Jovanović, A., Kosanic, N., Petrović, A. Lj.,& Levic, L. (2016). Granular flow in static mixers by coupled DEM/CFD approach.
Hemijska industrija, 70(5), 539-546.
https://doi.org/10.2298/HEMIND151013060P
Pezo L, Pezo ML, Jovanović A, Kosanic N, Petrović AL, Levic L. Granular flow in static mixers by coupled DEM/CFD approach. Hemijska industrija. 2016;70(5):539-546
Pezo Lato, Pezo Milada L., Jovanović Aca, Kosanic Nenad, Petrović Aleksandar Lj., Levic Ljubinko, "Granular flow in static mixers by coupled DEM/CFD approach" Hemijska industrija, 70, no. 5 (2016):539-546,
https://doi.org/10.2298/HEMIND151013060P .
1
1
1

Technical and Economic Analysis of Grid-Connected PV/Wind Energy Stations in the Republic of Serbia Under Varying Climatic Conditions

Bakić, Vukman; Pezo, Milada L.; Stojkovic, Sasa M.

(2016)

TY  - JOUR
AU  - Bakić, Vukman
AU  - Pezo, Milada L.
AU  - Stojkovic, Sasa M.
PY  - 2016
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/1689
AB  - In this paper technical and economic analysis of grid-connected PV/Wind energy systems located in the Republic of Serbia are presented. The technical and economic data, of the various grid-connected PV/Wind hybrid energy systems for three different locations: Novi Sad, Belgrade and Kopaonik, using the transient simulations software TRNSYS and HOMER were obtained. The results obtained in this paper show that locations and technical characteristics of the energy systems have an important influence on the amount of delivering electrical power to the grid. The CO2 emissions reductions, obtained on the basis of delivered electrical power to distribution networks are also analyzed. Economic analysis is carried out using Life Cycling Cost (LCC) method. The adoption and implementation of feed-in tariffs have a significant role in enhancing the implementation of technologies that use renewable energy resources.
T2  - FME Transactions
T1  - Technical and Economic Analysis of Grid-Connected PV/Wind Energy Stations in the Republic of Serbia Under Varying Climatic Conditions
VL  - 44
IS  - 1
SP  - 71
EP  - 82
DO  - 10.5937/fmet1601071B
ER  - 
@article{
author = "Bakić, Vukman and Pezo, Milada L. and Stojkovic, Sasa M.",
year = "2016",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/1689",
abstract = "In this paper technical and economic analysis of grid-connected PV/Wind energy systems located in the Republic of Serbia are presented. The technical and economic data, of the various grid-connected PV/Wind hybrid energy systems for three different locations: Novi Sad, Belgrade and Kopaonik, using the transient simulations software TRNSYS and HOMER were obtained. The results obtained in this paper show that locations and technical characteristics of the energy systems have an important influence on the amount of delivering electrical power to the grid. The CO2 emissions reductions, obtained on the basis of delivered electrical power to distribution networks are also analyzed. Economic analysis is carried out using Life Cycling Cost (LCC) method. The adoption and implementation of feed-in tariffs have a significant role in enhancing the implementation of technologies that use renewable energy resources.",
journal = "FME Transactions",
title = "Technical and Economic Analysis of Grid-Connected PV/Wind Energy Stations in the Republic of Serbia Under Varying Climatic Conditions",
volume = "44",
number = "1",
pages = "71-82",
doi = "10.5937/fmet1601071B"
}
Bakić, V., Pezo, M. L.,& Stojkovic, S. M. (2016). Technical and Economic Analysis of Grid-Connected PV/Wind Energy Stations in the Republic of Serbia Under Varying Climatic Conditions.
FME Transactions, 44(1), 71-82.
https://doi.org/10.5937/fmet1601071B
Bakić V, Pezo ML, Stojkovic SM. Technical and Economic Analysis of Grid-Connected PV/Wind Energy Stations in the Republic of Serbia Under Varying Climatic Conditions. FME Transactions. 2016;44(1):71-82
Bakić Vukman, Pezo Milada L., Stojkovic Sasa M., "Technical and Economic Analysis of Grid-Connected PV/Wind Energy Stations in the Republic of Serbia Under Varying Climatic Conditions" FME Transactions, 44, no. 1 (2016):71-82,
https://doi.org/10.5937/fmet1601071B .
6
6
7

Numerical Prediction of Nucleate Pool Boiling Heat Transfer Coefficient under High Heat Fluxes

Pezo, Milada L.; Stevanovic, Vladimir D.

(2016)

TY  - JOUR
AU  - Pezo, Milada L.
AU  - Stevanovic, Vladimir D.
PY  - 2016
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/1138
AB  - This paper presents computational fluid dynamics approach to prediction of the heat transfer coefficient for nucleate pool boiling under high heat fluxes. The 3-D numerical simulations of the atmospheric saturated pool boiling are performed. Mathematical modelling of pool boiling requires a treatment of vapor-liquid two-phase mixture on the macro level, as well as on the micro level, such as bubble growth and departure from the heating surface. Two-phase flow is modelled by the two-fluid model, which consists of the mass, momentum, and energy conservation equations for each phase. Interface transfer processes are calculated by the closure laws. Micro level phenomena on the heating surface are modelled with the bubble nucleation site density, the bubble resistance time on the heating wall and with the certain level of randomness in the location of bubble nucleation sites. The developed model was used to determine the heat transfer coefficient and results of numerical simulations are compared with available experimental results and several empirical correlations. A considerable scattering of the predictions of the pool boiling heat transfer coefficient by experimental correlations is observed, while the numerically predicted values are within the range of results calculated by well-known Kutateladze, Mostinski, Kruzhilin, and Rohsenow correlations. The presented numerical modelling approach is original regarding both the application of the two-fluid two-phase model for the determination of heat transfer coefficient in pool boiling and the defined boundary conditions at the heated wall surface.
T2  - Thermal Science
T1  - Numerical Prediction of Nucleate Pool Boiling Heat Transfer Coefficient under High Heat Fluxes
VL  - 20
SP  - S113
EP  - S123
DO  - 10.2298/TSCI150701138P
ER  - 
@article{
author = "Pezo, Milada L. and Stevanovic, Vladimir D.",
year = "2016",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/1138",
abstract = "This paper presents computational fluid dynamics approach to prediction of the heat transfer coefficient for nucleate pool boiling under high heat fluxes. The 3-D numerical simulations of the atmospheric saturated pool boiling are performed. Mathematical modelling of pool boiling requires a treatment of vapor-liquid two-phase mixture on the macro level, as well as on the micro level, such as bubble growth and departure from the heating surface. Two-phase flow is modelled by the two-fluid model, which consists of the mass, momentum, and energy conservation equations for each phase. Interface transfer processes are calculated by the closure laws. Micro level phenomena on the heating surface are modelled with the bubble nucleation site density, the bubble resistance time on the heating wall and with the certain level of randomness in the location of bubble nucleation sites. The developed model was used to determine the heat transfer coefficient and results of numerical simulations are compared with available experimental results and several empirical correlations. A considerable scattering of the predictions of the pool boiling heat transfer coefficient by experimental correlations is observed, while the numerically predicted values are within the range of results calculated by well-known Kutateladze, Mostinski, Kruzhilin, and Rohsenow correlations. The presented numerical modelling approach is original regarding both the application of the two-fluid two-phase model for the determination of heat transfer coefficient in pool boiling and the defined boundary conditions at the heated wall surface.",
journal = "Thermal Science",
title = "Numerical Prediction of Nucleate Pool Boiling Heat Transfer Coefficient under High Heat Fluxes",
volume = "20",
pages = "S113-S123",
doi = "10.2298/TSCI150701138P"
}
Pezo, M. L.,& Stevanovic, V. D. (2016). Numerical Prediction of Nucleate Pool Boiling Heat Transfer Coefficient under High Heat Fluxes.
Thermal Science, 20, S113-S123.
https://doi.org/10.2298/TSCI150701138P
Pezo ML, Stevanovic VD. Numerical Prediction of Nucleate Pool Boiling Heat Transfer Coefficient under High Heat Fluxes. Thermal Science. 2016;20:S113-S123
Pezo Milada L., Stevanovic Vladimir D., "Numerical Prediction of Nucleate Pool Boiling Heat Transfer Coefficient under High Heat Fluxes" Thermal Science, 20 (2016):S113-S123,
https://doi.org/10.2298/TSCI150701138P .
6
6
7

Structural Analysis of Guyed Mast Exposed to Wind Action

Pezo, Milada L.; Bakić, Vukman; Marković, Zoran M.

(2016)

TY  - JOUR
AU  - Pezo, Milada L.
AU  - Bakić, Vukman
AU  - Marković, Zoran M.
PY  - 2016
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/7137
AB  - The behavior of the mast is non-linear due to its slenderness and compliant guy-support system, having a tendency to lose stability and even crush suddenly. Wind load is one of the main factors affecting the stability of the structure of the mast. Structural assessment of the different mast configurations has been investigated in the past. Furthermore, European standards EN 1993-3-1:2006 and EN 1993-1-6:2007 already provides some guidelines about the basis of structural analysis of masts and towers. This paper presents the results of numerical simulations of a guyed mast exposed to wind action using finite element method. Structural analyses were performed for three different constant wind loads, modal analysis provides the values of natural frequency and mode shapes, while the stability analysis was performed for the first three buckling load factor values. The motivation for this study is to investigate the contribution of finite element method to structural analysis of a lattice structure such as guyed mast as an alternative and/or improvement to the literature and codes.
T2  - Thermal Science
T1  - Structural Analysis of Guyed Mast Exposed to Wind Action
VL  - 20
SP  - S1473
EP  - S1483
DO  - 10.2298/TSCI16S5473P
ER  - 
@article{
author = "Pezo, Milada L. and Bakić, Vukman and Marković, Zoran M.",
year = "2016",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/7137",
abstract = "The behavior of the mast is non-linear due to its slenderness and compliant guy-support system, having a tendency to lose stability and even crush suddenly. Wind load is one of the main factors affecting the stability of the structure of the mast. Structural assessment of the different mast configurations has been investigated in the past. Furthermore, European standards EN 1993-3-1:2006 and EN 1993-1-6:2007 already provides some guidelines about the basis of structural analysis of masts and towers. This paper presents the results of numerical simulations of a guyed mast exposed to wind action using finite element method. Structural analyses were performed for three different constant wind loads, modal analysis provides the values of natural frequency and mode shapes, while the stability analysis was performed for the first three buckling load factor values. The motivation for this study is to investigate the contribution of finite element method to structural analysis of a lattice structure such as guyed mast as an alternative and/or improvement to the literature and codes.",
journal = "Thermal Science",
title = "Structural Analysis of Guyed Mast Exposed to Wind Action",
volume = "20",
pages = "S1473-S1483",
doi = "10.2298/TSCI16S5473P"
}
Pezo, M. L., Bakić, V.,& Marković, Z. M. (2016). Structural Analysis of Guyed Mast Exposed to Wind Action.
Thermal Science, 20, S1473-S1483.
https://doi.org/10.2298/TSCI16S5473P
Pezo ML, Bakić V, Marković ZM. Structural Analysis of Guyed Mast Exposed to Wind Action. Thermal Science. 2016;20:S1473-S1483
Pezo Milada L., Bakić Vukman, Marković Zoran M., "Structural Analysis of Guyed Mast Exposed to Wind Action" Thermal Science, 20 (2016):S1473-S1483,
https://doi.org/10.2298/TSCI16S5473P .
2
3
3

Modified screw conveyor-mixers - Discrete element modeling approach

Pezo, Lato; Jovanović, Aca; Pezo, Milada L.; Čolović, Radmilo; Lončar, Biljana

(2015)

TY  - JOUR
AU  - Pezo, Lato
AU  - Jovanović, Aca
AU  - Pezo, Milada L.
AU  - Čolović, Radmilo
AU  - Lončar, Biljana
PY  - 2015
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/755
AB  - Screw conveyors are widely used in the food industry, building construction and mining companies, chemical, agricultural and processing industries, mostly for elevating and/or transporting bulk materials over short to medium distances. Despite their apparent simplicity, the improvement of the transport parameters is a very demanding task and designers usually have to rely on data obtained from empirical investigations. In this paper, fifteen horizontal single-pitch screw conveyors with modified geometry and the different lengths were investigated for premixing action, during the transport of materials. All investigations were performed experimentally and numerically, by using Discrete Element Method (DEM). The influences of screw length, observed geometry variations and different types of screw design, on the performances of the screw conveyor-mixer during material transport were explored. The auxiliary mixing action (used to improve the mixing process) was achieved during the transport of the material. The geometry of the screw conveyor is changed by adding three complementary helices oriented in the same or the opposite direction from screw blades. The particles of the material being transported tumble down from the top of the helix to the next free surface, and that segment of helix was used for additional mixing action. According to experiments and DEM analysis, the particle path length is increased, with the observed modification of screw conveyor, and the improved geometry could be determined for increasing the quality of mixing. (C) 2015 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.
T2  - Advanced Powder Technology
T1  - Modified screw conveyor-mixers - Discrete element modeling approach
VL  - 26
IS  - 5
SP  - 1391
EP  - 1399
DO  - 10.1016/j.apt.2015.07.016
ER  - 
@article{
author = "Pezo, Lato and Jovanović, Aca and Pezo, Milada L. and Čolović, Radmilo and Lončar, Biljana",
year = "2015",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/755",
abstract = "Screw conveyors are widely used in the food industry, building construction and mining companies, chemical, agricultural and processing industries, mostly for elevating and/or transporting bulk materials over short to medium distances. Despite their apparent simplicity, the improvement of the transport parameters is a very demanding task and designers usually have to rely on data obtained from empirical investigations. In this paper, fifteen horizontal single-pitch screw conveyors with modified geometry and the different lengths were investigated for premixing action, during the transport of materials. All investigations were performed experimentally and numerically, by using Discrete Element Method (DEM). The influences of screw length, observed geometry variations and different types of screw design, on the performances of the screw conveyor-mixer during material transport were explored. The auxiliary mixing action (used to improve the mixing process) was achieved during the transport of the material. The geometry of the screw conveyor is changed by adding three complementary helices oriented in the same or the opposite direction from screw blades. The particles of the material being transported tumble down from the top of the helix to the next free surface, and that segment of helix was used for additional mixing action. According to experiments and DEM analysis, the particle path length is increased, with the observed modification of screw conveyor, and the improved geometry could be determined for increasing the quality of mixing. (C) 2015 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.",
journal = "Advanced Powder Technology",
title = "Modified screw conveyor-mixers - Discrete element modeling approach",
volume = "26",
number = "5",
pages = "1391-1399",
doi = "10.1016/j.apt.2015.07.016"
}
Pezo, L., Jovanović, A., Pezo, M. L., Čolović, R.,& Lončar, B. (2015). Modified screw conveyor-mixers - Discrete element modeling approach.
Advanced Powder Technology, 26(5), 1391-1399.
https://doi.org/10.1016/j.apt.2015.07.016
Pezo L, Jovanović A, Pezo ML, Čolović R, Lončar B. Modified screw conveyor-mixers - Discrete element modeling approach. Advanced Powder Technology. 2015;26(5):1391-1399
Pezo Lato, Jovanović Aca, Pezo Milada L., Čolović Radmilo, Lončar Biljana, "Modified screw conveyor-mixers - Discrete element modeling approach" Advanced Powder Technology, 26, no. 5 (2015):1391-1399,
https://doi.org/10.1016/j.apt.2015.07.016 .
28
21
33

DEM/CFD analysis of granular flow in static mixers

Jovanović, Aca; Pezo, Milada L.; Pezo, Lato; Levic, Ljubinko

(2014)

TY  - JOUR
AU  - Jovanović, Aca
AU  - Pezo, Milada L.
AU  - Pezo, Lato
AU  - Levic, Ljubinko
PY  - 2014
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/87
AB  - Mixing of powders, particles and/or granules obtains an economic importance in various technologies, and in the food, pharmaceutical and chemical industries. In many cases, the mixing process greatly influences the quality of the final product. The parameters of the mixing process and the design of equipment have a strong impact on the mixing efficiency, and the quality and the price of the intermediate or final product. In this study, the discrete element method (DEM) is used for modeling of granular flow in various multiple Komax and Ross mixing applications. Computational fluid dynamic (CFD) method was used for modeling of fluid flow through the Eulerian multiphase model. Coupling of these two methods provides reliable, sufficiently correct and adequate results of the proposed model compared to experimental measurements. The objective of this paper is to predict the behavior of particles in different static mixer configurations. The results of the numerical simulation are compared with appropriate experimental results. Application of this model provides the optimization of the geometry and parameters of mixing systems taking into account the quality of the mixing process and the cost of the final product. (C) 2014 Elsevier B.V. All rights reserved.
T2  - Powder Technology
T1  - DEM/CFD analysis of granular flow in static mixers
VL  - 266
SP  - 240
EP  - 248
DO  - 10.1016/j.powtec.2014.06.032
ER  - 
@article{
author = "Jovanović, Aca and Pezo, Milada L. and Pezo, Lato and Levic, Ljubinko",
year = "2014",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/87",
abstract = "Mixing of powders, particles and/or granules obtains an economic importance in various technologies, and in the food, pharmaceutical and chemical industries. In many cases, the mixing process greatly influences the quality of the final product. The parameters of the mixing process and the design of equipment have a strong impact on the mixing efficiency, and the quality and the price of the intermediate or final product. In this study, the discrete element method (DEM) is used for modeling of granular flow in various multiple Komax and Ross mixing applications. Computational fluid dynamic (CFD) method was used for modeling of fluid flow through the Eulerian multiphase model. Coupling of these two methods provides reliable, sufficiently correct and adequate results of the proposed model compared to experimental measurements. The objective of this paper is to predict the behavior of particles in different static mixer configurations. The results of the numerical simulation are compared with appropriate experimental results. Application of this model provides the optimization of the geometry and parameters of mixing systems taking into account the quality of the mixing process and the cost of the final product. (C) 2014 Elsevier B.V. All rights reserved.",
journal = "Powder Technology",
title = "DEM/CFD analysis of granular flow in static mixers",
volume = "266",
pages = "240-248",
doi = "10.1016/j.powtec.2014.06.032"
}
Jovanović, A., Pezo, M. L., Pezo, L.,& Levic, L. (2014). DEM/CFD analysis of granular flow in static mixers.
Powder Technology, 266, 240-248.
https://doi.org/10.1016/j.powtec.2014.06.032
Jovanović A, Pezo ML, Pezo L, Levic L. DEM/CFD analysis of granular flow in static mixers. Powder Technology. 2014;266:240-248
Jovanović Aca, Pezo Milada L., Pezo Lato, Levic Ljubinko, "DEM/CFD analysis of granular flow in static mixers" Powder Technology, 266 (2014):240-248,
https://doi.org/10.1016/j.powtec.2014.06.032 .
29
25
37

Numerical determination of drag coefficient for guyed mast exposed to wind action

Pezo, Milada L.; Bakić, Vukman

(2014)

TY  - JOUR
AU  - Pezo, Milada L.
AU  - Bakić, Vukman
PY  - 2014
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/5940
AB  - Guyed masts are used for meteorological measurements, in the telecommunication industry for wireless communication or for power transmission. For a guyed mast, wind load is the main factor affecting the stability of the structure. Determination of drag coefficient for lattice structure has been investigate in past. ESDU 81027 and 81028 and Eurocode 3 Part 3.1 give already some detailed information of the aerodynamic drag coefficient of lattice mast structures with circular members. Only certain types of lattice masts covers literature and codes tend to be conservative due to the necessity of simplicity. But in this study is presented numerical method using Computational Fluid Dynamics (CFD) to determine drag coefficient. The motivation for this study to investigate what CFD can offer or contribute to determine the aerodynamic drag forces of lattice mast structures as a supplement or even alternative to literature and codes. This would be in particular of interest for design engineers in the field of mast structures. Three-dimensional numerical simulations of one segment of a mast exposed to a wind action with three models of turbulence are performed. Three models of turbulence: standard k-epsilon model, RNG k-epsilon model and Reynolds stress model were used and compared with available experimental results. Drag coefficient was calculated based on integration surface pressure distribution, flow field and a reference area. Modeling was performed for four wind velocities, 10 m/s, 20 m/s, 30 m/s and 40 m/s. Reynolds number for those velocities corresponds to turbulence flow. Direction of inlet velocity is also variable, e.g. there are two angles of attack. (C) 2014 Elsevier Ltd. All rights reserved.
T2  - Engineering Structures
T1  - Numerical determination of drag coefficient for guyed mast exposed to wind action
VL  - 62-63
SP  - 98
EP  - 104
DO  - 10.1016/j.engstruct.2014.01.025
ER  - 
@article{
author = "Pezo, Milada L. and Bakić, Vukman",
year = "2014",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/5940",
abstract = "Guyed masts are used for meteorological measurements, in the telecommunication industry for wireless communication or for power transmission. For a guyed mast, wind load is the main factor affecting the stability of the structure. Determination of drag coefficient for lattice structure has been investigate in past. ESDU 81027 and 81028 and Eurocode 3 Part 3.1 give already some detailed information of the aerodynamic drag coefficient of lattice mast structures with circular members. Only certain types of lattice masts covers literature and codes tend to be conservative due to the necessity of simplicity. But in this study is presented numerical method using Computational Fluid Dynamics (CFD) to determine drag coefficient. The motivation for this study to investigate what CFD can offer or contribute to determine the aerodynamic drag forces of lattice mast structures as a supplement or even alternative to literature and codes. This would be in particular of interest for design engineers in the field of mast structures. Three-dimensional numerical simulations of one segment of a mast exposed to a wind action with three models of turbulence are performed. Three models of turbulence: standard k-epsilon model, RNG k-epsilon model and Reynolds stress model were used and compared with available experimental results. Drag coefficient was calculated based on integration surface pressure distribution, flow field and a reference area. Modeling was performed for four wind velocities, 10 m/s, 20 m/s, 30 m/s and 40 m/s. Reynolds number for those velocities corresponds to turbulence flow. Direction of inlet velocity is also variable, e.g. there are two angles of attack. (C) 2014 Elsevier Ltd. All rights reserved.",
journal = "Engineering Structures",
title = "Numerical determination of drag coefficient for guyed mast exposed to wind action",
volume = "62-63",
pages = "98-104",
doi = "10.1016/j.engstruct.2014.01.025"
}
Pezo, M. L.,& Bakić, V. (2014). Numerical determination of drag coefficient for guyed mast exposed to wind action.
Engineering Structures, 62-63, 98-104.
https://doi.org/10.1016/j.engstruct.2014.01.025
Pezo ML, Bakić V. Numerical determination of drag coefficient for guyed mast exposed to wind action. Engineering Structures. 2014;62-63:98-104
Pezo Milada L., Bakić Vukman, "Numerical determination of drag coefficient for guyed mast exposed to wind action" Engineering Structures, 62-63 (2014):98-104,
https://doi.org/10.1016/j.engstruct.2014.01.025 .
2
3
3

Dynamical simulation of PV/Wind hybrid energy conversion system

Bakić, Vukman; Pezo, Milada L.; Stevanović, Žana; Živković, Marija M.; Grubor, Borislav

(2012)

TY  - JOUR
AU  - Bakić, Vukman
AU  - Pezo, Milada L.
AU  - Stevanović, Žana
AU  - Živković, Marija M.
AU  - Grubor, Borislav
PY  - 2012
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/5054
AB  - In this paper, a PV/Wind integrated hybrid power energy system is analyzed using the dynamical simulation method. The market for the distributed power generation based on renewable energy is increasing, particularly for the standalone mini-grid applications. The main design components of PV/Wind hybrid system are the PV panels and the wind turbine. The case study is realized using the meteorological data for a Typical Metrological Year (TMY) for the city of Belgrade, in Serbia. The dynamical analysis is based on the transient system simulation program TRNSYS 16. The purpose of the study is to design a realistic energy system that maximizes the use of renewable energy and minimizes the use of fossil fuels. The reduction in the CO2 emissions is also analyzed in the paper. (C) 2011 Elsevier Ltd. All rights reserved.
T2  - Energy
T1  - Dynamical simulation of PV/Wind hybrid energy conversion system
VL  - 45
IS  - 1
SP  - 324
EP  - 328
DO  - 10.1016/j.energy.2011.11.063
ER  - 
@article{
author = "Bakić, Vukman and Pezo, Milada L. and Stevanović, Žana and Živković, Marija M. and Grubor, Borislav",
year = "2012",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/5054",
abstract = "In this paper, a PV/Wind integrated hybrid power energy system is analyzed using the dynamical simulation method. The market for the distributed power generation based on renewable energy is increasing, particularly for the standalone mini-grid applications. The main design components of PV/Wind hybrid system are the PV panels and the wind turbine. The case study is realized using the meteorological data for a Typical Metrological Year (TMY) for the city of Belgrade, in Serbia. The dynamical analysis is based on the transient system simulation program TRNSYS 16. The purpose of the study is to design a realistic energy system that maximizes the use of renewable energy and minimizes the use of fossil fuels. The reduction in the CO2 emissions is also analyzed in the paper. (C) 2011 Elsevier Ltd. All rights reserved.",
journal = "Energy",
title = "Dynamical simulation of PV/Wind hybrid energy conversion system",
volume = "45",
number = "1",
pages = "324-328",
doi = "10.1016/j.energy.2011.11.063"
}
Bakić, V., Pezo, M. L., Stevanović, Ž., Živković, M. M.,& Grubor, B. (2012). Dynamical simulation of PV/Wind hybrid energy conversion system.
Energy, 45(1), 324-328.
https://doi.org/10.1016/j.energy.2011.11.063
Bakić V, Pezo ML, Stevanović Ž, Živković MM, Grubor B. Dynamical simulation of PV/Wind hybrid energy conversion system. Energy. 2012;45(1):324-328
Bakić Vukman, Pezo Milada L., Stevanović Žana, Živković Marija M., Grubor Borislav, "Dynamical simulation of PV/Wind hybrid energy conversion system" Energy, 45, no. 1 (2012):324-328,
https://doi.org/10.1016/j.energy.2011.11.063 .
35
32
34

Technical Analysis of Photovoltaic/Wind Systems with Hydrogen Storage

Bakić, Vukman; Pezo, Milada L.; Jovanović, Marina P.; Turanjanin, Valentina; Vučićević, Biljana S.; Mirkov, Nikola S.

(2012)

TY  - JOUR
AU  - Bakić, Vukman
AU  - Pezo, Milada L.
AU  - Jovanović, Marina P.
AU  - Turanjanin, Valentina
AU  - Vučićević, Biljana S.
AU  - Mirkov, Nikola S.
PY  - 2012
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/5063
AB  - The technical analysis of a hybrid wind-photovoltaic energy system with hydrogen gas storage was studied. The market for the distributed power generation based on renewable energy is increasing, particularly for the standalone minigrid applications. The main design components of photovoltaic/wind hybrid system are the photovoltaic panels, the wind turbine and an alkaline electrolyzer with tank. The technical analysis is based on the transient system simulation program TRNSYS 16. The study is realized using the meteorological data for a Typical Metrological Year for region of Novi Sad, Belgrade cities, and Kopaonik national park in Serbia. The purpose of the study is to design a realistic energy system that maximizes the use of renewable energy and minimizes the use of fossil fuels. The reduction in the CO2 emissions is also analyzed in the paper.
T2  - Thermal Science
T1  - Technical Analysis of Photovoltaic/Wind Systems with Hydrogen Storage
VL  - 16
IS  - 3
SP  - 865
EP  - 875
DO  - 10.2298/TSCI120306132B
ER  - 
@article{
author = "Bakić, Vukman and Pezo, Milada L. and Jovanović, Marina P. and Turanjanin, Valentina and Vučićević, Biljana S. and Mirkov, Nikola S.",
year = "2012",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/5063",
abstract = "The technical analysis of a hybrid wind-photovoltaic energy system with hydrogen gas storage was studied. The market for the distributed power generation based on renewable energy is increasing, particularly for the standalone minigrid applications. The main design components of photovoltaic/wind hybrid system are the photovoltaic panels, the wind turbine and an alkaline electrolyzer with tank. The technical analysis is based on the transient system simulation program TRNSYS 16. The study is realized using the meteorological data for a Typical Metrological Year for region of Novi Sad, Belgrade cities, and Kopaonik national park in Serbia. The purpose of the study is to design a realistic energy system that maximizes the use of renewable energy and minimizes the use of fossil fuels. The reduction in the CO2 emissions is also analyzed in the paper.",
journal = "Thermal Science",
title = "Technical Analysis of Photovoltaic/Wind Systems with Hydrogen Storage",
volume = "16",
number = "3",
pages = "865-875",
doi = "10.2298/TSCI120306132B"
}
Bakić, V., Pezo, M. L., Jovanović, M. P., Turanjanin, V., Vučićević, B. S.,& Mirkov, N. S. (2012). Technical Analysis of Photovoltaic/Wind Systems with Hydrogen Storage.
Thermal Science, 16(3), 865-875.
https://doi.org/10.2298/TSCI120306132B
Bakić V, Pezo ML, Jovanović MP, Turanjanin V, Vučićević BS, Mirkov NS. Technical Analysis of Photovoltaic/Wind Systems with Hydrogen Storage. Thermal Science. 2012;16(3):865-875
Bakić Vukman, Pezo Milada L., Jovanović Marina P., Turanjanin Valentina, Vučićević Biljana S., Mirkov Nikola S., "Technical Analysis of Photovoltaic/Wind Systems with Hydrogen Storage" Thermal Science, 16, no. 3 (2012):865-875,
https://doi.org/10.2298/TSCI120306132B .
10
9
11

Numerička simulacija krize ključanja u isparivačkim cevima

Pezo, Milada L.

(Универзитет у Београду, Машински факултет, 2011)

TY  - BOOK
AU  - Pezo, Milada L.
PY  - 2011
UR  - http://eteze.bg.ac.rs/application/showtheses?thesesId=535
UR  - https://fedorabg.bg.ac.rs/fedora/get/o:6576/bdef:Content/download
UR  - http://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=513716899
UR  - http://nardus.mpn.gov.rs/123456789/2308
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/7247
AB  - Predmet ovog rada je numerička simulacija i analiza trodimenzionalnog dvofaznog strujanja i istraživanje mehanizama krize ključanja u isparivačkim cevima. Kriza ključanja je nepovoljna pojava. Nagli porast temperature zida cevi izaziva termomehanička naprezanja, koja mogu dovesti do pojave prskotina i pucanja cevi pod pritiskom.Razvijen je matematički model dvofaznog strujanja u isparivačkoj cevi,koji se sastoji od jednačina održanja mase, količine kretanja i energije za obe faze. Sastoji se od sistema parcijalnih diferencijalnih jednačinakoje su rečavane za definisane granične uslove.Bilo je neophodno uvesti i modeliranje i numeričku simulaciju na mikro nivou, jer je bilo potrebno ispitati i proces pojave i rasta mehura, kao i ponašanje dvofazne mešavine na zagrejačkoj površini na makroskopskom nivou.Rezultati numeričkih simulacija su upoređeni sa raspoloživim eksperimentalnim rezultatima.
AB  - The subject of this thesis is numerical simulation and analyses of three dimensional two-phase flow and mechanism of boiling crises in evaporation pipes. Boiling crises is characterized by a dried out heat surface and can bring physical destruction of the heater. A developed mathematical model of two phase flow in evaporation pipe consists of prescribed mass, momentum and energy conservation equations for liquid and vapor two-phase flow. It consists of set of partial differential equations which were solved for specific boundary conditions. Modeling of the micro scale level was necessary to take into account processes of the bubble rise and behavior of the two-phase mixture at the heating surface. Results of the numerical simulation are compared with similar available results of the experiments from the literature.
PB  - Универзитет у Београду, Машински факултет
T2  - Универзитет у Београду
T1  - Numerička simulacija krize ključanja u isparivačkim cevima
T1  - Numerical simulation of boiling crises mechanism in evaporation pipes
ER  - 
@phdthesis{
author = "Pezo, Milada L.",
year = "2011",
url = "http://eteze.bg.ac.rs/application/showtheses?thesesId=535, https://fedorabg.bg.ac.rs/fedora/get/o:6576/bdef:Content/download, http://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=513716899, http://nardus.mpn.gov.rs/123456789/2308, http://vinar.vin.bg.ac.rs/handle/123456789/7247",
abstract = "Predmet ovog rada je numerička simulacija i analiza trodimenzionalnog dvofaznog strujanja i istraživanje mehanizama krize ključanja u isparivačkim cevima. Kriza ključanja je nepovoljna pojava. Nagli porast temperature zida cevi izaziva termomehanička naprezanja, koja mogu dovesti do pojave prskotina i pucanja cevi pod pritiskom.Razvijen je matematički model dvofaznog strujanja u isparivačkoj cevi,koji se sastoji od jednačina održanja mase, količine kretanja i energije za obe faze. Sastoji se od sistema parcijalnih diferencijalnih jednačinakoje su rečavane za definisane granične uslove.Bilo je neophodno uvesti i modeliranje i numeričku simulaciju na mikro nivou, jer je bilo potrebno ispitati i proces pojave i rasta mehura, kao i ponašanje dvofazne mešavine na zagrejačkoj površini na makroskopskom nivou.Rezultati numeričkih simulacija su upoređeni sa raspoloživim eksperimentalnim rezultatima., The subject of this thesis is numerical simulation and analyses of three dimensional two-phase flow and mechanism of boiling crises in evaporation pipes. Boiling crises is characterized by a dried out heat surface and can bring physical destruction of the heater. A developed mathematical model of two phase flow in evaporation pipe consists of prescribed mass, momentum and energy conservation equations for liquid and vapor two-phase flow. It consists of set of partial differential equations which were solved for specific boundary conditions. Modeling of the micro scale level was necessary to take into account processes of the bubble rise and behavior of the two-phase mixture at the heating surface. Results of the numerical simulation are compared with similar available results of the experiments from the literature.",
publisher = "Универзитет у Београду, Машински факултет",
journal = "Универзитет у Београду",
title = "Numerička simulacija krize ključanja u isparivačkim cevima, Numerical simulation of boiling crises mechanism in evaporation pipes"
}
Pezo, M. L. (2011). Numerical simulation of boiling crises mechanism in evaporation pipes.
Универзитет у Београду
Универзитет у Београду, Машински факултет..
Pezo ML. Numerical simulation of boiling crises mechanism in evaporation pipes. Универзитет у Београду. 2011;
Pezo Milada L., "Numerical simulation of boiling crises mechanism in evaporation pipes" Универзитет у Београду (2011)

Numerical Simulation of the Air Flow Around the Arrays of Solar Collectors

Bakić, Vukman; Živković, Goran S.; Pezo, Milada L.

(2011)

TY  - JOUR
AU  - Bakić, Vukman
AU  - Živković, Goran S.
AU  - Pezo, Milada L.
PY  - 2011
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/4403
AB  - This paper deals with the numerical simulation of air flow around the arrays of flat plate collectors and determination of the flow field, which should provide a basis for estimating a convective heat losses, a parameter which influences their working characteristics. Heat losses are the result of the reflection on the glass, conductive losses at the collectors absorber plate, radiation of the absorber plate and convective losses on the glass. Wind velocity in the vicinity of the absorber plate depends on its position in the arrays of collectors. Results obtained in the numerical simulation of flow around collectors were used as boundary conditions in modeling of thermal-hydraulic processes inside the solar collector. A method for coupling thermal-hydraulic processes inside the collector with heat transfer from plate to tube bundle was developed, in order to find out the distribution of the temperature of the absorber plate and the efficiency of the flat plate collectors. Analyses of flow around arrays of collectors are preformed with RNG k-epsilon model. Three values for free-stream velocity were analysed, i.e. 1 m/s, 5 m/s, and 10 m/s, as well as two values for the angle between the ground and the collector (20 degrees and 40 degrees). Heat transfer coefficient was determined from the theory of boundary layer. Heat transfer inside the plate cavity was analyzed assuming constant intensity of radiation.
T2  - Thermal Science
T1  - Numerical Simulation of the Air Flow Around the Arrays of Solar Collectors
VL  - 15
IS  - 2
SP  - 457
EP  - 465
DO  - 10.2298/TSCI110222051B
ER  - 
@article{
author = "Bakić, Vukman and Živković, Goran S. and Pezo, Milada L.",
year = "2011",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/4403",
abstract = "This paper deals with the numerical simulation of air flow around the arrays of flat plate collectors and determination of the flow field, which should provide a basis for estimating a convective heat losses, a parameter which influences their working characteristics. Heat losses are the result of the reflection on the glass, conductive losses at the collectors absorber plate, radiation of the absorber plate and convective losses on the glass. Wind velocity in the vicinity of the absorber plate depends on its position in the arrays of collectors. Results obtained in the numerical simulation of flow around collectors were used as boundary conditions in modeling of thermal-hydraulic processes inside the solar collector. A method for coupling thermal-hydraulic processes inside the collector with heat transfer from plate to tube bundle was developed, in order to find out the distribution of the temperature of the absorber plate and the efficiency of the flat plate collectors. Analyses of flow around arrays of collectors are preformed with RNG k-epsilon model. Three values for free-stream velocity were analysed, i.e. 1 m/s, 5 m/s, and 10 m/s, as well as two values for the angle between the ground and the collector (20 degrees and 40 degrees). Heat transfer coefficient was determined from the theory of boundary layer. Heat transfer inside the plate cavity was analyzed assuming constant intensity of radiation.",
journal = "Thermal Science",
title = "Numerical Simulation of the Air Flow Around the Arrays of Solar Collectors",
volume = "15",
number = "2",
pages = "457-465",
doi = "10.2298/TSCI110222051B"
}
Bakić, V., Živković, G. S.,& Pezo, M. L. (2011). Numerical Simulation of the Air Flow Around the Arrays of Solar Collectors.
Thermal Science, 15(2), 457-465.
https://doi.org/10.2298/TSCI110222051B
Bakić V, Živković GS, Pezo ML. Numerical Simulation of the Air Flow Around the Arrays of Solar Collectors. Thermal Science. 2011;15(2):457-465
Bakić Vukman, Živković Goran S., Pezo Milada L., "Numerical Simulation of the Air Flow Around the Arrays of Solar Collectors" Thermal Science, 15, no. 2 (2011):457-465,
https://doi.org/10.2298/TSCI110222051B .
3
6
8

Numerical prediction of critical heat flux in pool boiling with the two-fluid model

Pezo, Milada L.; Stevanovic, Vladimir

(2011)

TY  - JOUR
AU  - Pezo, Milada L.
AU  - Stevanovic, Vladimir
PY  - 2011
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/4395
AB  - Three-dimensional numerical simulations of the atmospheric saturated pool boiling are performed with the aim of predicting the critical heat flux. The two-phase mixture in pool boiling is described with the transient two-fluid model. The transient heat conduction in the horizontal heated wall is also solved. Dynamics of vapor generation on the heated wall is modeled through the density of nucleation sites and the bubble residence time on the wall. The heaters surface is divided into zones, which number per unit area equals the density of nucleation sites, while the location of nucleation site within each zone is determined by a random function. The results show a replenishment of the heaters surface with water and surface wetting for lower heat fluxes, while heaters surface dry-out is predicted at critical heat flux values. Also, it is shown that the decrease of nucleation site density leads to the reduction of critical heat flux values. Obtained results of critical heat flux are in good agreement with available measured data. The presented approach is original regarding both the application of the two-fluid two-phase model for the prediction of boiling crisis in pool boiling and the defined boundary conditions at the heated wall surface. (C) 2011 Elsevier Ltd. All rights reserved.
T2  - International Journal of Heat and Mass Transfer
T1  - Numerical prediction of critical heat flux in pool boiling with the two-fluid model
VL  - 54
IS  - 15-16
SP  - 3296
EP  - 3303
DO  - 10.1016/j.ijheatmasstransfer.2011.03.057
ER  - 
@article{
author = "Pezo, Milada L. and Stevanovic, Vladimir",
year = "2011",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/4395",
abstract = "Three-dimensional numerical simulations of the atmospheric saturated pool boiling are performed with the aim of predicting the critical heat flux. The two-phase mixture in pool boiling is described with the transient two-fluid model. The transient heat conduction in the horizontal heated wall is also solved. Dynamics of vapor generation on the heated wall is modeled through the density of nucleation sites and the bubble residence time on the wall. The heaters surface is divided into zones, which number per unit area equals the density of nucleation sites, while the location of nucleation site within each zone is determined by a random function. The results show a replenishment of the heaters surface with water and surface wetting for lower heat fluxes, while heaters surface dry-out is predicted at critical heat flux values. Also, it is shown that the decrease of nucleation site density leads to the reduction of critical heat flux values. Obtained results of critical heat flux are in good agreement with available measured data. The presented approach is original regarding both the application of the two-fluid two-phase model for the prediction of boiling crisis in pool boiling and the defined boundary conditions at the heated wall surface. (C) 2011 Elsevier Ltd. All rights reserved.",
journal = "International Journal of Heat and Mass Transfer",
title = "Numerical prediction of critical heat flux in pool boiling with the two-fluid model",
volume = "54",
number = "15-16",
pages = "3296-3303",
doi = "10.1016/j.ijheatmasstransfer.2011.03.057"
}
Pezo, M. L.,& Stevanovic, V. (2011). Numerical prediction of critical heat flux in pool boiling with the two-fluid model.
International Journal of Heat and Mass Transfer, 54(15-16), 3296-3303.
https://doi.org/10.1016/j.ijheatmasstransfer.2011.03.057
Pezo ML, Stevanovic V. Numerical prediction of critical heat flux in pool boiling with the two-fluid model. International Journal of Heat and Mass Transfer. 2011;54(15-16):3296-3303
Pezo Milada L., Stevanovic Vladimir, "Numerical prediction of critical heat flux in pool boiling with the two-fluid model" International Journal of Heat and Mass Transfer, 54, no. 15-16 (2011):3296-3303,
https://doi.org/10.1016/j.ijheatmasstransfer.2011.03.057 .
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Sustainability estimation of energy system options that use gas and renewable resources for domestic hot water production

Jovanović, Marina P.; Turanjanin, Valentina; Bakić, Vukman; Pezo, Milada L.; Vučićević, Biljana S.

(2011)

TY  - JOUR
AU  - Jovanović, Marina P.
AU  - Turanjanin, Valentina
AU  - Bakić, Vukman
AU  - Pezo, Milada L.
AU  - Vučićević, Biljana S.
PY  - 2011
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/6906
AB  - Two possible substitutions for fossil fuel used in heat production are biomass and solar energy. This paper presents an evaluation of various energy sources for hot water production in a heating plant. The heating plant was situated in one of the largest municipalities in the city of Belgrade, Serbia. It produces and delivers domestic hot water and energy for heating to approximately 17,000 households. It is possible to use of using renewable energy instead of fossil fuel for producing the thermal energy for the supply of domestic hot water. Hence, in this paper, an evaluation of the sustainability of different energy options for obtaining thermal energy was considered: 1) from gas combustion: 2) from gas combustion and solar collection 3) from biomass combustion 4) from gas and biomass combustion, and 5) from gas and biomass combustion and solar collection. To compare the different energy systems, the method of multi-criteria analysis was utilised. This method integrates various multi-dimensional criteria and provides an efficient method of estimating the sustainability of complex systems. The obtained results were compared by the General Index of Sustainability which is a measure of the complexity of a system. A basic set of energy indicators that relate to different aspects of sustainable development was defined. In this way, the results in the assessment of sustainability of energy options do not depend on the various analysts in decision making. (C) 2010 Elsevier Ltd. All rights reserved.
T2  - Energy
T1  - Sustainability estimation of energy system options that use gas and renewable resources for domestic hot water production
VL  - 36
IS  - 4
SP  - 2169
EP  - 2175
DO  - 10.1016/j.energy.2010.08.042
ER  - 
@article{
author = "Jovanović, Marina P. and Turanjanin, Valentina and Bakić, Vukman and Pezo, Milada L. and Vučićević, Biljana S.",
year = "2011",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/6906",
abstract = "Two possible substitutions for fossil fuel used in heat production are biomass and solar energy. This paper presents an evaluation of various energy sources for hot water production in a heating plant. The heating plant was situated in one of the largest municipalities in the city of Belgrade, Serbia. It produces and delivers domestic hot water and energy for heating to approximately 17,000 households. It is possible to use of using renewable energy instead of fossil fuel for producing the thermal energy for the supply of domestic hot water. Hence, in this paper, an evaluation of the sustainability of different energy options for obtaining thermal energy was considered: 1) from gas combustion: 2) from gas combustion and solar collection 3) from biomass combustion 4) from gas and biomass combustion, and 5) from gas and biomass combustion and solar collection. To compare the different energy systems, the method of multi-criteria analysis was utilised. This method integrates various multi-dimensional criteria and provides an efficient method of estimating the sustainability of complex systems. The obtained results were compared by the General Index of Sustainability which is a measure of the complexity of a system. A basic set of energy indicators that relate to different aspects of sustainable development was defined. In this way, the results in the assessment of sustainability of energy options do not depend on the various analysts in decision making. (C) 2010 Elsevier Ltd. All rights reserved.",
journal = "Energy",
title = "Sustainability estimation of energy system options that use gas and renewable resources for domestic hot water production",
volume = "36",
number = "4",
pages = "2169-2175",
doi = "10.1016/j.energy.2010.08.042"
}
Jovanović, M. P., Turanjanin, V., Bakić, V., Pezo, M. L.,& Vučićević, B. S. (2011). Sustainability estimation of energy system options that use gas and renewable resources for domestic hot water production.
Energy, 36(4), 2169-2175.
https://doi.org/10.1016/j.energy.2010.08.042
Jovanović MP, Turanjanin V, Bakić V, Pezo ML, Vučićević BS. Sustainability estimation of energy system options that use gas and renewable resources for domestic hot water production. Energy. 2011;36(4):2169-2175
Jovanović Marina P., Turanjanin Valentina, Bakić Vukman, Pezo Milada L., Vučićević Biljana S., "Sustainability estimation of energy system options that use gas and renewable resources for domestic hot water production" Energy, 36, no. 4 (2011):2169-2175,
https://doi.org/10.1016/j.energy.2010.08.042 .
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Fossil fuels substitution by the solar energy utilization for the hot water production in the heating plant Cerak in Belgrade

Turanjanin, Valentina; Bakić, Vukman; Jovanović, Marina P.; Pezo, Milada L.

(2009)

TY  - JOUR
AU  - Turanjanin, Valentina
AU  - Bakić, Vukman
AU  - Jovanović, Marina P.
AU  - Pezo, Milada L.
PY  - 2009
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/6837
AB  - The main objective of this paper is to evaluate energy and environmental benefits of the large-scale solar heating system connection with district heating system. The assessment of fossil fuels substitution by the solar energy for the hot water production for domestic use, during the summer period, is done. Hot water for district heating and domestic use is produced in heating plant Cerak placed in the suburb of Belgrade. The existing production and distribution system are based on fossil fuel energy, mainly on the natural gas. in the first phase of the project plan was to install about 10,000 m(2) of solar collectors to substitute nearly 25% of natural gas consumption. During the summer period, the saving of natural gas calculated for presented system is approximately 430,000 m(3) and in this way 900 t of the CO(2) emissions would be reduced. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.
T2  - International Journal of Hydrogen Energy
T1  - Fossil fuels substitution by the solar energy utilization for the hot water production in the heating plant Cerak in Belgrade
VL  - 34
IS  - 16
SP  - 7075
EP  - 7080
DO  - 10.1016/j.ijhydene.2008.11.005
ER  - 
@article{
author = "Turanjanin, Valentina and Bakić, Vukman and Jovanović, Marina P. and Pezo, Milada L.",
year = "2009",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/6837",
abstract = "The main objective of this paper is to evaluate energy and environmental benefits of the large-scale solar heating system connection with district heating system. The assessment of fossil fuels substitution by the solar energy for the hot water production for domestic use, during the summer period, is done. Hot water for district heating and domestic use is produced in heating plant Cerak placed in the suburb of Belgrade. The existing production and distribution system are based on fossil fuel energy, mainly on the natural gas. in the first phase of the project plan was to install about 10,000 m(2) of solar collectors to substitute nearly 25% of natural gas consumption. During the summer period, the saving of natural gas calculated for presented system is approximately 430,000 m(3) and in this way 900 t of the CO(2) emissions would be reduced. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.",
journal = "International Journal of Hydrogen Energy",
title = "Fossil fuels substitution by the solar energy utilization for the hot water production in the heating plant Cerak in Belgrade",
volume = "34",
number = "16",
pages = "7075-7080",
doi = "10.1016/j.ijhydene.2008.11.005"
}
Turanjanin, V., Bakić, V., Jovanović, M. P.,& Pezo, M. L. (2009). Fossil fuels substitution by the solar energy utilization for the hot water production in the heating plant Cerak in Belgrade.
International Journal of Hydrogen Energy, 34(16), 7075-7080.
https://doi.org/10.1016/j.ijhydene.2008.11.005
Turanjanin V, Bakić V, Jovanović MP, Pezo ML. Fossil fuels substitution by the solar energy utilization for the hot water production in the heating plant Cerak in Belgrade. International Journal of Hydrogen Energy. 2009;34(16):7075-7080
Turanjanin Valentina, Bakić Vukman, Jovanović Marina P., Pezo Milada L., "Fossil fuels substitution by the solar energy utilization for the hot water production in the heating plant Cerak in Belgrade" International Journal of Hydrogen Energy, 34, no. 16 (2009):7075-7080,
https://doi.org/10.1016/j.ijhydene.2008.11.005 .
8
6
7

A two-dimensional model of the kettle reboiler shell side thermal-hydraulics

Pezo, Milada L.; Stevanovic, VD; Stevanović, Žarko M.

(2006)

TY  - JOUR
AU  - Pezo, Milada L.
AU  - Stevanovic, VD
AU  - Stevanović, Žarko M.
PY  - 2006
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/2991
AB  - A two-dimensional two-fluid numerical model is developed for the prediction of two-phase flow thermal-hydraulics on the shell side of the kettle reboiler. The two-phase flow around tubes in the bundle is modeled with the porous media approach. A closure law for the vapour-liquid interfacial friction is based on modified pipe two-phase flow correlations. The tube bundle flow resistance is calculated by applying to each phase stream the correlations for the pressure drop in a single phase flow across tube bundles and by taking into account the separate contribution of each phase to the total pressure drop. Physically based boundary conditions for the velocity field at the two-phase mixture swell level are stated. The system of governing equations is solved numerically with the finite volume approach for two-phase flow built in the commercial computer program. Simulations are performed for available conditions of performed physical experiments. In comparison to the previous kettle reboiler two-dimensional modeling approaches, here presented model is original regarding the applied closure laws for the interfacial friction and bundle flow resistance, as well as applied boundary conditions for the modeling of two-phase mixture free surface. Also, regarding the previous published results, here obtained numerical results are compared with the available measured data of void fraction within the tube bundle and acceptable agreement is shown. (c) 2005 Elsevier Ltd. All rights reserved.
T2  - International Journal of Heat and Mass Transfer
T1  - A two-dimensional model of the kettle reboiler shell side thermal-hydraulics
VL  - 49
IS  - 7-8
SP  - 1214
EP  - 1224
DO  - 10.1016/j.ijheatmasstransfer.2005.10.004
ER  - 
@article{
author = "Pezo, Milada L. and Stevanovic, VD and Stevanović, Žarko M.",
year = "2006",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/2991",
abstract = "A two-dimensional two-fluid numerical model is developed for the prediction of two-phase flow thermal-hydraulics on the shell side of the kettle reboiler. The two-phase flow around tubes in the bundle is modeled with the porous media approach. A closure law for the vapour-liquid interfacial friction is based on modified pipe two-phase flow correlations. The tube bundle flow resistance is calculated by applying to each phase stream the correlations for the pressure drop in a single phase flow across tube bundles and by taking into account the separate contribution of each phase to the total pressure drop. Physically based boundary conditions for the velocity field at the two-phase mixture swell level are stated. The system of governing equations is solved numerically with the finite volume approach for two-phase flow built in the commercial computer program. Simulations are performed for available conditions of performed physical experiments. In comparison to the previous kettle reboiler two-dimensional modeling approaches, here presented model is original regarding the applied closure laws for the interfacial friction and bundle flow resistance, as well as applied boundary conditions for the modeling of two-phase mixture free surface. Also, regarding the previous published results, here obtained numerical results are compared with the available measured data of void fraction within the tube bundle and acceptable agreement is shown. (c) 2005 Elsevier Ltd. All rights reserved.",
journal = "International Journal of Heat and Mass Transfer",
title = "A two-dimensional model of the kettle reboiler shell side thermal-hydraulics",
volume = "49",
number = "7-8",
pages = "1214-1224",
doi = "10.1016/j.ijheatmasstransfer.2005.10.004"
}
Pezo, M. L., Stevanovic, V.,& Stevanović, Ž. M. (2006). A two-dimensional model of the kettle reboiler shell side thermal-hydraulics.
International Journal of Heat and Mass Transfer, 49(7-8), 1214-1224.
https://doi.org/10.1016/j.ijheatmasstransfer.2005.10.004
Pezo ML, Stevanovic V, Stevanović ŽM. A two-dimensional model of the kettle reboiler shell side thermal-hydraulics. International Journal of Heat and Mass Transfer. 2006;49(7-8):1214-1224
Pezo Milada L., Stevanovic VD, Stevanović Žarko M., "A two-dimensional model of the kettle reboiler shell side thermal-hydraulics" International Journal of Heat and Mass Transfer, 49, no. 7-8 (2006):1214-1224,
https://doi.org/10.1016/j.ijheatmasstransfer.2005.10.004 .
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