Buoyancy Combined with Buildings Layout Effects on the Thermal Diffusion under Background Wind: Wind Tunnel PIV Measurement

¹ College of Civil Engineering, Northeast Forestry University, China
² Key Laboratory of Cold Region Urban and Rural Human Settlement Environment Science and Technology Ministry of Industry and Information Technology, School of Architecture, Harbin Institute of Technology, China

Corresponding author: hithdl2020@163.com

Abstract

The temperature in the urban areas are higher compared with rural areas because of the UHI effect. The wind-driven ventilation play a significant role on the heat removal. Moreover, the air velocity in the urban areas is influenced by the background wind speed, the exposure of heated surfaces and building layout. However, available experimental data for the thermal diffusion mechanism of different heat source conditions and building layout is limited. Aim at the problem above, the thermal diffusion mechanism of different surface heating conditions and building layout was analysed by conducting wind tunnel experiment with PIV system. To investigate the thermal diffusion mechanism, the building façade, impervious road surface, and traditional roof are heated up three different temperatures to induce buoyant. The effects of three different buildings layouts on flow and temperature also were investigated in this paper. The results showed that building layouts had a marked impact on the flow field near buildings. The terraced building layout is best for heat removal. This study improves understanding of how the buoyancy and wind speed influence the thermal diffusion in different buildings layouts, expands experimental database under different surface temperature conditions and buildings layouts in wind tunnel experiments with PIV.