2008 Volume 50 Issue 153 Pages 255-263
Effects of radiation feedback on flame spread behavior along polymer-insulated wire in microgravity are investigated numerically. Polyethylene-insulated nickel-chrome (NiCr) wire is considered as the test sample since the experimental data of this sample are available. Time-dependent, 2-D heat and mass transport processes with one-step finite rate reaction model in gas phase as well as solid phase are numerically solved. Forced weak flow is given from one end of the domain and opposed flame spread mode is of interest in the present study. Radiation energy transport from the (sooty) flame to the unburned solid is modeled with the simplest way and parametric study are performed to elucidate the importance of radiative energy transfer on the precise prediction of the flame spread behavior. It turns out that flame spread behavior in near-quiescent regime has strong sensitivity on the imposed radiation properties, suggesting that proper radiation model must be included for the precise prediction of the flame spread behavior in microgravity. In addition, our model predicts that 10 s (corresponding to the maximum microgravity duration brought by JAMIC) might be insufficient to achieve steady state in an ideal quiescent environment. To make further concern on the feasibility study of the numerical model, long-term microgravity test would be necessary.
