Analysis of natural and forced convection heat losses from a thermal manikin: Comparative assessment of the static and dynamic postures

The present experimental work is dedicated to the analysis of the effect of walking movements and air velocity on the convective heat transfer coefficients (h(conv)) of the human body. A wind tunnel and an articulated thermal manikin of the Pernille type with sixteen body segments were used. Beyond the standing posture (static condition), a step rate of 45 steps/min was selected, corresponding to a walking speed of 0.51 m/s (dynamic condition). The free stream air velocity was varied from 0 to about 10 m/s. The experimental conditions were thus varied from natural to forced convection. The convection coefficients for the different body segments and the whole body were determined for each air velocity giving details about the differences between them. In the case of the whole body, for the standing static reference posture and free convection, the mean value of h(conv) was equal to 3.5 W m(-2) degrees C-1. In the dynamic condition the corresponding h(conv) value was 4.5 W m(-2) degrees C-1. In forced convection, the highest values correspond to the highest wind speed and were equal to 22.4 W m(-2) degrees C-1 for the static condition and 23.0 W m(-2) degrees C-1 for the dynamic posture. (C) 2014 Elsevier Ltd. All rights reserved.