THERMAL MODELING OF ICE-PACKS IN COOLING VESTS FOR EXTREME HOT CLIMATIC CONDITION: A NUMERICAL APPROACH
Prevention of heat related injuries caused by prolonged exposure to extreme hot climate during outdoor activities in summer or fire-fighting can be addressed by cooling vests with the provision of carrying ice-packs. Since ice has large fusion enthalpy (335 kj?kg), melting process of ice is capable of absorbing large amounts of thermal energy and thus can be used to protect the body from thermal injuries. A suitable thickness of insulating material is however necessary in order to maintain the body surface temperature within the comfort range of 33 ± 2 °C. The present work aims at evaluating the thermal comfort duration for a given configuration of ice-pack stacked between two layers of insulating materials. Detailed CFD modeling for the melting of ice stacked between insulators is performed considering exterior of one of the insulators to be exposed to high temperature (~50°C) while the other insulating side is in contact with the body. The predicted body-surface temperatures obtained from numerical model are validated with the experimentally measured body-surface side temperature, which provided a reasonable agreement. Particularly the trend of skin temperature variation over time is well captured by the model.