Response of a confined gas to volumetric heating in the absence of gravity. I: Slow transients

Abstract

A one-dimensional model for bulk motion induced by a transient volumetric heat source in a confined gas at zero gravity is considered. Rational approximation methods are used to derive a quantitative theory for the gas response to a spatially distributed, time-dependent internal power deposition. The resulting low Mach number compressible flow equations are solved by using perturbation methods. Solutions are given for a conduction-free core and thin conductive boundary layers adjacent to the end walls. It is found that any spatially nonuniform power deposition will cause fluid motion. Net mass transport in the closed container will occur for certain spatially distributed heating. The model mimics the thermal effects of an exothermic gas phase reaction in vapor transport experiments conducted in space. The solutions demonstrate that thermally induced mass transport can be as large as diffusive mass transport in a typical experiment.