Study on coupling characteristics of supersonic inlet and pulse detonation combustor

超声速进气道与脉冲爆震燃烧室匹配工作特性研究

School of Power and Energy, Northwestern Polytechnical University, Xi'an 710072, China

Received: 10 June 2022

Abstract

Coupling model for two-dimensional mixed-compression supersonic inlet with Mach number of 2.5 at design point and pulse detonation combustor was established, and three working schemes were designed to investigate multi cycle working process by using unsteady numerical simulation with chemical reaction. The results show that the following two measurements can both restrain the back-propagating compression wave and broaden the stability margin of the inlet and increase the frequency, one of which is the pressure relief at the outlet of the combustor, the other is valve at the inlet of the combustor. Nevertheless, the former will lose thrust, while the latter can greatly increase thrust. Meanwhile, the valve will reflect the compression wave in the production; increase the turbulence in the combustor, and make the gas entrained into the diffuser section of the inlet at the moment of opening the valve. However, the reflected compression wave in the hot production will not affect the velocity and shape of the detonation wave. Furthermore, in the period of detonation wave initiation and propagation, the blockage ratio of physical obstructions at the inlet of the combustor should be expanded as much as possible. At the same time, the flow at the outlet of the inlet should not be blocked to increase the flow resistance.

摘要

为探索设计点马赫数为2.5的三波系二元混压式超声速进气道与脉冲爆震燃烧室的匹配工作特性, 设计了3种工作方案, 采用带有化学反应的非定常数值仿真方法, 研究了多循环工作过程。结果表明: 燃烧室出口泄压与燃烧室进口机械阀均能抑制反传压缩波向上游的传播, 拓宽进气道稳定工作裕度, 且能提高循环频率; 但前者会损失推力, 而后者能大幅增加推力。机械阀会对燃气中的压缩波产生反射作用, 增大燃烧室内湍流度, 使得在开阀瞬间燃气被卷吸至上游扩张段内, 但燃气中的反射压缩波不会影响爆震波波速与形态。在爆震波起爆与传播过程中, 燃烧室进口应尽可能扩大物理遮挡物阻塞比, 且不应对进气道出口流动造成堵塞, 增加流动阻力。