Influence of Ignition Channel on the Ignition Performance of Ignition Device

Abstract

Based on relative theories of gas dynamics and computational fluid dynamics, the flow field computation software ANSYS Fluent was used to simulate the steady flow field of the solid type ignition device of liquid-propellant rocket engine in two working conditions (condition I: without ignition channel, condition II: with ignition channel). On this basis, the influence of ignition channel on the working characteristics of the solid type ignition device of the liquid-propellant rocket engine was analyzed and experimentally tested. The results showed that when the pressure in the combustion chamber was atmospheric pressure, under condition II, the gas velocity at the throat of the ignition device did not reach the sonic velocity, and the position of sonic velocity moved to the downstream section of the ignition channel. Compared to condition I, the gas velocity and energy at the ignition outlet increased, which would be beneficial for initial ignition, and the gas pressure and temperature at the throat increased as well, indicating that the structural strength at the throat should be evaluated. The gas flow, gas pressure, and gas temperature at the ignition outlet decreased compared to working condition I, yet the changes were small and would have minimal effect on the ignition performance. During the pressure increase process in the combustion chamber, the gas pressure, velocity, temperature, flow, and energy at the ignition outlet experienced a steady stage in both working conditions before coming to an inflection point. The inflection point under condition II is smaller than that under condition I. To improve the ignition reliability, the working pressure of the ignition device should be further increased.