Prediction of Limiting Oxygen Concentration of Thin Materials in Microgravity

Abstract

In order to predict the flammability limit of thin materials in microgravity environments without conducting microgravity experiments, we developed a simplified model for flame spread in an opposed flow by introducing two non-dimensional parameters which represent radiative quenching and blow-off extinction. Thin PMMA sheet and NOMEX HT90-40 fabric were used as the sample. For predicting the blow-off limiting curve, the pre-exponential factor and the activation energy are required, however, these properties are hardly available in the literature. Hence, we proposed a novel blow-off test in a forced flow to obtain empirical parameters which reproduce the actual blow-off phenomena correctly. Although the properties of NOMEX are unknown, the limiting curves of NOMEX with these empirical parameters well agreed with the results of the parabolic flights, and the obtained minimum oxygen concentration was also close to the experimental value.

Flame spread behaviour of Polydimethylsiloxane (PDMS) membranes in 1 g and µg environments

“…� was used and is based on the an extended simplified theory (EST) developed by Bhattacharjee, Takahashi and co-workers [28,32,50]. The flame temperature (1200 °C) and the pyrolysis temperature (444 °C) were taken from the literature [3,7].…”