中心支板式RBCC发动机引射模态流动与燃烧研究

In order to realize a deeper understanding of the operational mechanism in the ejector mode, fully channel integrated numerical simulations were carried out on a central-strut based RBCC engine within different built-in rocket operational conditions at a typical flight Mach number of 2. In detail, the internal flow characteristics, the mixing and development characteristics of rocket jet and entrained air, as well as the heat release and flame structure were analyzed. It has been found that the mixing and combustion process in the RBCC engine adopting the Simultaneous Mixing and Combustion(SMC) cycle in the ejector mode was a complex and highly coupled process. In SMC combustion mode, the combustion was mainly carried out in the shear layer formed between the built-in rocket jet and the incoming air. The thickness of the shear layer at the upstream of the flow channel was thinner, the gradients of temperature and component concentration were larger, and the mixing rate was higher. The high heat release zone was mainly distributed in the upstream of the channel, which could be divided into supersonic and subsonic heat release zones. The reaction in the channel was mainly diffusion combustion, and gradually transited to premixed combustion along with the mixing process. With the increase of the rocket mass flow rate, the temperature and the reaction distance increases, however, the mixing efficiency decreases.