Effect of Gas Radiation on Radiative Heat Transfer in Urban Street Canyon Model

In this paper, we describe the results of numerical simulation of radiative heat transfer between the human body and an urban street canyon (building walls, pavement, and the sky) in the presence of participating non-gray gas mixtures consisting of H2O and CO2. The ambient temperature in typical summer conditions and the concentration of gas mixtures during summer in Tokyo were assumed. Further, the parallel infinite plane model and simple urban street canyon model were used. The results show that the participating gas significantly affects the infrared radiation field in an urban street canyon. The radiation flux emitted by the participating gas is approximately 35% of the total radiation flux incident on the human body surface. This causes a homogenization of the infrared radiation field surrounding the human body. Gas radiation plays an important role in the heat transfer between the human body and the environment under hot and humid summer conditions. (C) 2009 Wiley Periodicals, Inc.