Effect of ambient pressure on the extinction limit for opposed flame spread over an electrical wire in microgravity

Parabolic flight experiments were carried out to investigate the effect of ambient pressure on extinction limit for opposed flame spread over an electric wire insulation in microgravity. Low-density polyethylene insulated Nickel-Chrome wires with inner core diameter 0.50 mm and thickness 0.30 examined pressures ranging from 50 kPa 140 external flow 10 cm/s. The showed that limiting volumetric oxygen concentration (LOC) increased as total decreased. This LOC trend can be explained by radiation loss surface. decreased – a result increase preheat length decreasing pressure. Moreover, when data was plotted partial vs. space, it became evident (LOPP) LOPP fact temperature under constant In current fire safety design spacecraft, tentative criteria spacecraft suggested NASA is assumed 30% concentration, this value independent However, present implies consideration flammability necessary, especially respect possibility extension allowable atmosphere condition cabin low region.