论文部分内容阅读
针对支板喷注煤油和一次火箭引导燃烧的RBCC发动机,在亚燃模态下的高效燃烧组织和性能开展了实验研究和数值分析。实验验证了在亚燃模态低来流总温条件下,使用小流量富燃一次火箭产生的高温射流作为引导火焰,可以实现支板喷注二次燃料的可靠点火和高效稳定燃烧。通过数值模拟获得了燃烧室的详细流场特征和燃烧组织细节,分析表明支板后方集中的燃料热释放可形成扩张燃烧室流道中的“热力壅塞”;通过热力喉道的控制,实现了在直扩流道内的高效燃烧。研究表明:发动机在亚燃模态下燃烧组织应尽可能地使热力喉道处于燃烧室较后位置,使燃料在燃烧室高压区内充分燃烧释热,从而提高其燃烧效率。论文还研究了燃料支板喷注位置的影响,进一步开展RBCC发动机亚燃模态性能的优化。
For the RBCC engine with kerosene injection and primary rocket-guided combustion, experimental studies and numerical analyzes were carried out on the high-efficiency combustion structure and properties in the sub-combustion mode. Experiments show that under the condition of low flow and total temperature in the sub-combustion mode, the high-temperature jet generated by a small-volume fuel-rich primary rocket can be used as the pilot flame to achieve reliable ignition and efficient and stable combustion of the secondary fuel injected into the support plate. The detailed flow field characteristics and combustion organization details of the combustion chamber are obtained by numerical simulation. The analysis shows that the concentrated fuel heat release at the back of the support plate can form a “thermal plug” in the flow passage of the expanded combustion chamber. Through the control of the thermal throat, In the direct expansion of the flow within the efficient combustion. The research shows that the engine combustion structure in the sub-combustion mode should make the thermal throat be located at the later position of the combustion chamber as much as possible, so that the fuel can fully burn and release heat in the high pressure area of the combustion chamber so as to improve the combustion efficiency. The paper also studies the influence of fuel jet injection position and further optimizes the sub-combustion modal performance of RBCC engine.