Thermal Manikin and Thermoregulatory Modeling Evaluation of Footwear Systems Using Standard Test Methods and Emerging Wet Footwear Test Methods

This report focuses on the biophysical evaluation of footwear through the use of standard thermal manikin testing methods and a new method that evaluates wet footwear. The Six Cylinder Thermoregulatory Model (SCTM) was used to determine foot endurance time, which is the amount of time Soldiers are able to function before a cold injury is likely to occur. The SCTM predicted foot endurance time of five dry footwear configurations to be between 34 and 49 minutes with the subject at rest, and between 43 and 99 minutes with the subject working at a total metabolic rate of 250 W. The predicted foot endurance time for two wet footwear configurations is between 28 and 36 minutes for a subject at rest and between 34 and 48 minutes for a subject working at a total metabolic rate of 250 W. The simulated air temperature was -51 deg C. The wet thermal resistance results showed between 7% and 22% decrease from the dry footwear thermal resistance. Water saturation in the footwear decreased thermal resistance and endurance times by approximately 5 minutes.