Combustion with source flows

The set of conservation equations that governs the behavior of a chemically-active material is what one might call naturally inhomogeneous in view of the need to incorporate algebraic information within it about the rates of production of individual chemical species. There are circumstances for which it is expedient to augment this natural array of algebraic terms, by including others that account for the appearance of distributed sources of mass, momentum, and energy within the material. f indication is given of how such ideas can be made consistent with physically-realistic events in a two-phase flow. They are then used to construct a simple model of events that take place during ignition of solid propellants that burn in the gas-phase. The model can be used as a test problem for computer codes; it also forms a basis on which to build more detailed models of the complex physical processes involved in two-phase combustion.