Laboratory studies related to the potential for thermal burns due to high-temperature airbag exhaust gas were conducted. A laboratory apparatus was constructed to produce a 10-mm-diameter jet of hot air that was directed onto the leg skin of human volunteers in time-controlled pulses. Skin burns were produced in 70 of 183 exposures conducted using air temperatures ranging from 350 to 550 degrees Celsius, air velocities from 50 to 90 m/s, and exposure durations from 50 to 300 ms. A mathematical model of heat transfer to the skin and burn injury was developed. This was done along with an empirical description of the threshold for partial-thickness skin burn as a function of gas velocity, gas temperature, and exposure duration. The mathematical burn injury model was combined with a lumped-parameter gas-dynamics model of airbag inflation to demonstrate the application of the skin thermal tolerance data to prediction of airbag-induced skin burn.
Abstract