Gas-particle flow in convergent nozzles at high loading ratios

Abstract

Abstract : Nozzle flows of gas-particle mixtures are analyzed for particle loadings for which the particle volume may not be negligible. Nozzle shapes are such that the particle velocity is a constant fraction of the gas velocity. The influence of various parameters which enter into the analysis is discussed. For loading ratios greater than about five, the gas and particle temperatures remain substantially constant for the entire flow, and the assumption of isothermal flow reduces the flow equations to algebraic relationships. Throat conditions then can be obtained directly without having to compute the entire flow. A procedure is outlined to evaluate the ranges of the loading ratio for which the assumption of either isothermal flow or of negligible particle volume keeps errors below a desired level, and it is found that these ranges may overlap. An important intermediate range of the loading ratio therefore exists, typically from about five to fifty, for which both simplifying assumptions are permissible with a resultant extreme simplification of the relationships. (Author)