Numerical modeling of transdermal heat transfer due to air bag deployment

One of the key selling points of present-day automobiles is such safety devices as the air bag. While air bags offer a high level of protection against head and chest injury, they also have the potential of producing minor injuries consisting primarily of skin abrasions and burns. The current research focus is to develop a method that will predict the likelihood of thermal injuries from the high-temperature air bag exhaust gas. In the present study a mathematical model of the heat transfer into the skin from the air bag exhaust gas is developed and solved numerically. An analytical solution is used to validate the numerical model during the air bag deflation period. In comparison with the models used by previous researchers, it was found that the present model is more realistic and accurate. A parametric study is performed to determine the relative importance of the gas jet velocity, gas jet temperature, air bag deflation time, and vent-to-skin spacing. If was found that the gas jet velocity and air bag deflation time resulted in the most significant changes in the maximum skin temperature for the range of parameters studied.