INTEGRATED DESIGN OF FOREBODY/INLET WITH DUAL-WAVERIDER IN THE STREAM DIRECTION BASED ON DISCRETE ISO-CONTRACTION RATIO

The integrated forebody/inlet design is an essential enabler for air vehicles targeting hypersonic flight regimes. The crux of this integrated design lies in achieving the aerodynamic fusion between the forebody and inlet in the baseline flow field. Based on the idea of the discrete equal contraction ratio consistent everywhere, this study puts forward a novel discrete iso-contraction ratio design approach to mitigate the detrimental impact of nonuniform flow induced by compression of the forebody on inlet performance in a ventral inlet configuration. This proposed method successfully attains the targeted aerodynamic fusion design between the waverider forebody and inward-turning inlet flows in conjunction with an aerodynamically-contoured variable cross-section duct design. In the proposed way, a three-dimensional inlet flowfield is decomposed into a bundle of three-dimensional flow tubes, which share identical contraction ratios. The side wall of each stream tube is treated as a virtual axisymmetric flowfield, and we optimize each three-dimensional stream tube by taking the nonuniform flow compressed by the conical-derived waverider forebody as design conditions and total pressure recovery as the design objective. These three-dimensional tubes are recombined into an inward-turning, variable cross-section inlet configuration by aligning shock reflection locations in the flow direction, with the respective three-dimensional tube boundaries forming the inlet contours. This design approach accommodates any given nonuniform inlet flow, allows flexible control over lip positioning, and enables variable cross-section transitions between arbitrary geometries. The numerical study is performed to preliminarily investigate the performance of the integrated configuration of waverider forebody and inward-turning inlet, and the results validate that the integrated configuration developed using this proposed method meets anticipated performance, evidenced by a uniform outlet flow and enhanced resistance to unstart. Favorable flow structures are also maintained at off-design conditions. This discrete iso-contraction ratio design methodology offers new perspectives on enabling aerodynamic fusion for integrated forebody/inlet designs in ventral inlet layouts.