Study of the risk of frostbite in humans with the help of a transient 3D finger model

Abstract

A new three dimensional transient human finger model was developed to predict the risk of frostbite in humans at different environmental conditions. The shape of the finger model was similar to that of a real human finger. Finite Element Techniques were used to build the finger model. Smith’s Model (1991) energy balance equations were used to calculate the temperatures in the current finger model. The current 3D finger model was validated against the experimental data of Wilson (1976) and Santee (1990). The model agreed well with the Wilson experiments and with the cold test in Santee experiments. The comparison indicates that the current finger model can be used to adequately predict the human finger responses in different environments. The current finger model was then tested in temperatures of 0, -10, -20, -25 and -30 oC and with different airspeeds 0, 3 and 6.8 m/s to assess the risk of frostbite in humans. Three resistances 0, 0.4 and 0.8 clo were used on the finger model to obtain responses in different environmental conditions. From the experimental results, an expression for safe glove resistance required to prevent frostbite in known temperatures was calculated. Also, the temperatures up to which a glove with known thermal resistance value can protect a human finger from frostbite was also computed.