A study of opposed flow smoldering of polyurethane foam: Comparison between normal- and microgravity.

摘要

An experimental study of one-dimensional opposed flow smolder of polyurethane foam has been carried out with an objective of providing a better understanding of the controlling mechanisms of smolder for the purpose of prevention and control, in both normal- and microgravity. The experiments are part of the NASA funded Microgravity Smoldering Combustion (MSC) research program, aimed to study the smolder characteristics of porous materials in a microgravity environment.;The energetic requirements for smolder initiation show a well defined smolder ignition regime primarily determined igniter power and the time the igniter is powered. An energy balance model, based on the assumption that for ignition to occur the igniter must provide a heat flux equivalent to that of a propagating smolder front at a given distance from the igniter, describes well the experimental observations. Smolder propagation is determined by the competition of heat generation and energy transfer to the gas with increased oxygen mass flux, which leads to a maximum in smolder front velocity. A critical oxygen mass flux (0.05 g/m