Numerical and experimental study on convective heat transfer of the human body in the outdoor environment

In this study, we measure the convective heat transfer coefficient for the human body in the outdoor environment by means of a wind tunnel test and computational fluid dynamics (CFD) analysis. A comparison of the results shows that the CFD analysis is sufficiently accurate. We conduct a sensitivity analysis based on CFD analysis for the mean convective heat transfer coefficient for the human body with changing values of velocity and turbulence intensity. We then develop a formula for the mean convective heat transfer coefficient for the human body in the outdoor environment that can evaluate both the influences of velocity and turbulence intensity of the wind on the human body. This formula is more effective for evaluating thermal comfort in the outdoor environment where there is large turbulence, because conventional formulae can evaluate only the influences of velocity. While the conventional formula produces an unrealistic increase in sensible temperature, the new formula causes the temperature to decrease, which is more reasonable, based on an analysis of thermal comfort in a tree-planted city block.