Prediction of high precision ignition process in the condition of multi flow area coupling of micro solid rocket motor.

With the shrinking of structure size, the pressure surge, oscillation and rapid heat transfer process in the transient ignition of SRM (solid rocket motor) become more and more complex. The multi physical field coupling among combustion, flow and thermal structure in the internal multi flow area of the micro motor makes a challenge and safety to the stability of the motor. In this paper, the ignition process of a micro solid rocket motor with multiple flow areas in the combustion chamber is numerically simulated based on the N-S equation and k-e turbulence model. Motor simulation with the practical work under the condition of the initial stage of simulation curves are in good agreement with the experimental curve. The simulated ignition sequence of the inside and outside surfaces of the main charge also explains the rising-falling trend of the pressure in the combustion chamber during the balancing work of the motor. Through the numerical simulation, the quantitative and qualitative analysis of the ignition section is carried out to obtain the flow field state of the combustion chamber in three typical periods of ignition. By analyzing the gas flow of the monitoring point at all times, the working process of the ignition section is predicted with high precision. Through the analysis of the transient physical parameters, more reference and selection basis and safety guarantee are provided for the reasonable design of the motor.