Numerical Study of Micro-Thermal Environment in Block Based on Porous Media Model

Abstract

The mitigation of the heat island effect has become one of the most challenging issues with the rapid urbanization and increased human activities. A standard model and a porous media model were developed to simulate the microthermal environment in the presence of anthropogenic heat in Nanjing Xinjiekou block. The accuracy of the simulation results was verified by field measurement data. Compared with the standard CFD method, the porous media method reduces the number of meshes by 27.8% and the total computation time by 66.7%. By comparing and analyzing the thermal environment of the block with various porosities and heat intensities at different heights, calculations proved that the velocity is positively correlated with the porosity change, and the temperature is negatively correlated with it in contrast. The temperature increases linearly with the increase in anthropogenic heat intensity under the block height range, and the gradient is about 0.025 K/W at the height of 2 m. The porous media approach allows for effective prediction of the micro-thermal environment in the initial stages of urban design while increasing the porosity of the block and controlling the intensity of anthropogenic heat emissions can be a prominent means of improving the thermal environment.