Experimental study of the effects of human movement on the convective heat transfer coefficient

Abstract

This present study is dedicated to the analysis of the effects of moving speed, moving direction angle and temperature difference between human body and environment on the convective heat transfer coefficients of the human body. The experiments were carried out in a full-scale cabin with a thermal manikin. Five moving speeds of the manikin (0.2, 0.5, 0.8, 1.1 and 1.3m/s) were carried out with a motor on a 10m-length-rail, and four temperature differences were selected (4, 8, 12 and 16°C) by changing the heating power of the manikin. Eight moving direction angles between the moving direction and the manikin face were set. In each experimental case, the temperatures of the environment and the wall in different heights were measured by the thermocouples to calculate the convective heat transfer coefficients. Through comparison with experimental data of the human body in wind tunnel, it can be demonstrated that the effect of the moving speed on the convective heat transfer coefficients is weaker than that of wind speed for the trunk parts of the manikin, while stronger for the upper limbs. The convective heat transfer coefficients are obviously affected by the moving direction angles under the moving condition for different body parts: in general the body parts having higher convective heat losses when they move against the wind. The experimental results also show that the convective heat transfer coefficients increase as the moving speeds and the temperature differences, i.e., the higher values correspond to the higher speeds and the higher temperature differences.