Zeitschrift für angewandten Maschinenbau

Abstrakt

Robust Modeling of Human Thermal Response to Hand and Forearm cooling for Improved Performance and Energy Efficiency

M Rida, W Karaki, N Ghaddar and K Ghali

A modeling approach is used to study the effectiveness of the Active Cooling (AC) method of hand and forearm immersion in cold water to reduce core temperature following heavy physical activity. A transient multi-node segmental bioheat model based on physiology and accurate mathematical modeling of thermoregulatory functions are used to predict human segmental core and skin temperatures, and arterial blood flow for given metabolic rate and environmental conditions. The validity of the model is confirmed by comparison with published experimental data on core temperature during and after immersion of forearms and hands in cold water. The validated model is used in a case study to enhance understanding of associated body thermal changes and arterial blood flow and AVA mechanisms during AC interventions that alleviate thermal stress in hot environment. The time needed for the core  temperature to drop from 38.0°C to 37.0°C is found to be 33 minutes when subject is at rest and is exposed to air cooling at 21°C compared to 15 minutes when hands and forearms are immersed in
water at 10°C. The average sensible heat loss during the cooling period associated with immersion of forearms and hands in water at 10°C was found to be 106.2 W compared to 75.9 W for passive air cooling at 21°C. The active cooling was found to be an effective method for accelerating reduction on core temperature and can be used with efficient, localized, and portable cooling devices.