Modeling of pressure-coupled response functions of solid propellants

Abstract

The applicability to various situations of a classic equation formulation commonly used to relate solid propellant pressure-coupled response functions to such steady-state combustion parameters as pressure and temperature sensitivity of burning rate has been examined. It is found that while this equation is valid under certain conditions, allowance for dependence of a surface heat release parameter on propellant conditioning temperature or for oscillations in the composition (oxidizer/fuel ratio) of material ablating from the propellant surface, accompanying surface temperature oscillations, invalidates this approach. In such cases, response functions calculated using this equation differ markedly from those calculated using a complete perturbation analysis. In addition, a potential destabilizing mechanism for heterogeneous propellants which is not present in the case of homogeneous propellants is identified, and an approach to improving combustion stability characteristics of composite propellants is suggested.