A Phenomenological Model for the Unsteady Combustion of Solid Propellants from a Zel’dovich-Novzhilov Approach

Solid rocket motors are prone to combustion instabilities, which may lead to various problems for the rockets, from unexpected oscillations, precision decreasing, to explosion. The unsteady combustion dynamics of the propellants play a crucial role in most solid rocket motors experiencing combustion instabilities. A modeling framework for the unsteady combustion of the solid propellant is constructed via the Zel’dovich-Novozhilov (ZN) phenomenological perspective. The overall unsteady combustion features of a quasi-steady homogeneous one-dimensional (QSHOD) model are investigated. The phenomenological ZN parameters are then calculated. Compared with the traditional ZN-QSHOD linear equivalence relation, the new calculated system yields better results for the pressure coupling response, especially in the non-linear regime. The proposed phenomenological modeling provides a new methodology for the model reduction of the complex flame models.