Combustion Organization of Micro-Solid Rocket Motor

A detailed reaction mechanism model of ammonium perchlorate-nitrocellulose (AP/NC) micro-propellant microscale combustion was established to further study the mechanism of propellant combustion in micro-solid rocket engine, which includes 64 components and 408 steps. Through user-defined functions (UDF) secondary development, the numerical calculation of microscale combustion of AP/NC micro-sized propellant was carried out. By coupling the primitive reaction with the flow and considering the diffusion mixing process of species transport, the prediction accuracy of micro-propellant combustion behavior was improved. The numerical results show that the critical premixed flame height rises first and then falls when the combustion pressure is increased. When the mass ratio of NC to AP in the propellant formulation is 1.1, the critical pressure is 8 MPa. At the same time, with the increase of pressure, the gas phase has a stronger conduction feedback effect near the burning surface, resulting in an increase in temperature. However, with the increase of NC content in the propellant formulation, the steady flame height decreases gradually.