Numerical analysis on RBCC inlets of different types in ejector mode

A two-dimensional RBCC inlet and a sidewall compression RBCC inlet were designed. By deploying the same embedded rocket, combustor and nozzle, integration numerical simulations were carried out on five typical flight conditions (Mach 0, 0.3, 0.9, 1.5 and 2.0), and the interior flow features and operational characteristics of the two different types of inlets were numerically compared and analyzed. (1) The operational state of the two RBCC inlets was extremely sensitive, and both strongly correlated with the flight condition, embedded rocket operation, and secondary combustion, etc.. (2) The key parameter of air entraining mass flow rate affected the RBCC engine performance significantly in the ejector mode. The inlet type had minor effect on its performance, and actually, the physical throat area of the RBCC inlet played the dominating role in the parameter. (3) Specially, the sidewall RBCC inlet exhibited better resistance to the serious flow separations, and correspondingly better air entrainment ability at Mach 0, while performed more excellent “low-drag” characteristic as the flight Mach number increased.