Bleeding control for improving internal waverider inlet self-starting ability

Internal waverider inlets (IWIs) are novel three-dimensional (3D) high-performance inward turning inlets. However, they possess poor self-starting capacity when applied in a fixed-geometry inlet for ramjets. Firstly, this paper presents an analysis of self-starting capacity for IWIs to demonstrate that IWIs face more difficult challenges when used as ramjet inlets than they do as scramjet inlets. Self-starting capacity must be taken into account when designing ramjet inlets. Secondly, the impact of a fluidic control method on a fixed-geometry IWI was studied by numerical simulation of fluid flow. The numerical results show that the fluidic control mechanism improved the self-starting capacity of the IWI at low Mach numbers: the minimum Mach number of self-starting capacity was reduced from M3.8 to M3.2; furthermore, the compression ratio was increased from 29.9 with no fluidic control to 31.9. By analyzing two different groups of fluidic control positions, it was determined that bleeding before the separation bubble has no impact on the IWI self-starting capacity.