Numerical Simulation of Wind Flow Influence on Heat Island Temperature Characteristics in Urban City Area

Abstract

The main aim of this paper is threedimensional (CFD) simulation of turbulent wind flow around realistic block of buildings located in city center in Belgrade, Serbia. Two different cases for different inlet wind directions were simulated. The first one in which wind flows from eastern direction, and the second one in which wind flows from southern direction. All input wind parameters (velocity magnitude, velocity direction, air temperature, outdoor radiative temperature) were obtained from complex measuring campaign performed in this area. The obtained results showed deep insight in velocity field, vortex structure and their influence on temperature increase of analyzed block of buildings area. It was shown that the main causes for the observed temperature increase are developed horizontal standing vortex structures. It was also shown that this negative effect is to some extent retarded by the presence of vertical recirculation zones which enhance heat transfer away from inner area of block of buildings. Influence of “Venturi effect” of narrow passage on low altitude wind speed increase was also determined. It was concluded that temperature increase is present in the both investigated cases. However, this temperature increase is significantly lower in the second case which was chosen as a more favorable.