Fire Propagation as a Function of Oxygen Concentration and Pressure

Astronauts, firefighters, the military, and the general public use fire-resistant fabrics to reduce the risk of skin burns, fire hazards, and fatalities. Understanding the effects of pressure on the oxygen concentration required for fire propagation is important for applications that deviate from standard atmospheric conditions. This work examines the effects of pressure levels, oxygen concentration, and flame configuration in fire propagation on Nomex and other fabrics. Concurrent and opposed fabric configurations are studied. The minimum and maximum critical oxygen concentrations for propagation are determined in a controlled chamber with fixed wind velocity and pressure levels, while varying the oxygen concentration. At lower pressure levels, higher oxygen concentrations are needed for the fires to propagate on Nomex. Concurrent configurations are observed to propagate more aggressively than opposed configurations on Nomex under the conditions tested. These results will be compared to tests on additional fabrics.