Numerical Simulation Of The Effects Of Thermal Environment On Microclimate In Residential Districts

The urban spatial form and the thermal characteristics of building wall materials have a very important effect on the urban microclimate.By setting different simulation conditions to find out the key factors and laws affecting the local microclimate,it can play a role in improving the local microclimate of the city,but also reduce the burden of urban energy consumption and improve the comfort of residential,and finally achieve the purpose of improving the ability of the city to cope with climate change.At present,the research on the thermal characteristics of residential building wall materials and the influence mechanism of urban local microclimate in China is not mature,and at the same time,there is a lack of analysis methods to comprehensively consider multiple influencing factors.In this paper,FLUENT is used to conduct numerical simulation research on the influence mechanism of residential thermal radiation environment and local microclimate under solar radiation conditions,and the research focuses on the radiation traps formed by multiple reflections of radiation in the denser building clusters.Through the establishment of a typical urban residential district model in Guangzhou,and with the climate of south China in summer as the meteorological background,the research is carried out.This topic mainly studies the influence of the sky view factor of the residential area and the thermal characteristics of wall materials(albedo)on the local microclimate of the city under the condition of solar radiation,so as to study the three-dimensional CFD numerical model established by buildings,pavement and air under different working conditions.By analyzing the relevant simulation results under different working conditions,the key factors and laws affecting the local microclimate are found out,and the relevant conclusions are drawn.At the same time,the degree of influence of different working conditions is evaluated by using the index of body sensation comfort and air conditioning energy consumption,so we can get the corresponding law of influence is obtained.The results of this research are summarized as follows: the local microclimate of the community is greatly affected by solar radiation.The solar radiation will have a strong influence on the temperature of concrete pavement.The atmospheric temperature in the near surface area changes greatly with the height from the ground,while the atmospheric temperature in the above near surface area gradually tends to slow with the height from the ground,and finally remains relatively stable.The change of thermal radiation environment will cause a great change to the local microclimate.Within a certain range,the larger sky view factor is,the higher average pavement temperature within the residential area will be.At the same time,the indoor and outdoor air temperature will rise to a certain extent,while the temperature of the wall will decline,and the more difficult the outdoor environment is to reach a more comfortable state.Under the least ideal sky view factor condition,the higher albedo of the wall material,the lower temperature of the wall will be.The air temperature at the outdoor pedestrian height increases slightly,while the indoor air temperature decreases to a certain extent,and the indoor energy consumption decreases to some extent.Appropriately reducing the sky view factor or choosing wall materials with higher albedo can effectively improve the thermal radiation environment inside the community,and at the same time play a better role in regulating the local microclimate.