HEAT AND MOISTURE TRANSPORT FROM A SWINGING LIMB OF A CLOTHED WALKING HUMAN
The paper extends the 3-D cylinder model of Ghaddar et al. (2005a) of the fabric-skin concentric cylinders system ventilation model with contact and no contact to accurately predict heat loss from skin for the true periodic rotational motion of the limb with respect to clothing during walking by using data of Lamoreux (1971) on the human gait. Extracted data on relative rotation of the hip during extension and flexion in the walking cycle are represented by simple correlations of the thigh segment kinematic parameters as a function of the stride length, walking speed, and swing time. The heat and moisture transport from the skin during the motion is governed by two mechanisms. The first transport mechanism is periodic ventilation when relative motion is present between fabric boundary and skin boundary while no contact takes place between the two boundaries. The second mechanism is by diffusion and convection to external environment when contact is present between fabric and skin system at finite intervals during the motion cycle. The modified cylinder model predicts the time-averaged steady-periodic sensible and latent heat loss for the limb. The rate of heat loss increases with increased ventilation frequency. The presence of an open aperture has a limited effect on increasing the total heat loss.