Experimental study on downward/opposed flame spread and extinction over electric wires in partial gravity environments

Downward/opposed flame spread over laboratory wire samples under varied gravity conditions were investigated in the range from 0 G to 1 G. Reduced experiments are conducted by parabolic flights of an airplane. Limiting oxygen concentrations (LOCs) and rates (Vf) obtained as a function level, with concentration, forced flow velocity, characteristics such insulation thickness core material experimental variables. The used this study consist low-density polyethylene (LDPE) metallic cores. Copper (Cu) nickel-chrome (NiCr) selected materials. It is found that effect on flammability varies thermal conductivity core; LOCs Cu sample less affected gravity, while those NiCr decrease decreasing level. On other hand, Vf increase monotonically increasing level sample, show peak value low conditions. suggested these differences response due difference materials controlled fuel concentration reaction zone, which Vf. also molten LDPE produced during process shows unique behaviors depending levels characteristics. Some dynamic motion process, deformation dripping, summarized paper. data provide useful information partial environment will serve database for fire safety design future space exploration.