Hypersonic Flow over V-Shaped Leading Edges: A Review of Shock Interactions and Aerodynamic Loads

For hypersonic air-breathing vehicles, the V-shaped leading edges (VSLEs) of supersonic combustion ramjet (scramjet) inlets experience complex shock interactions and intense aerodynamic loads. This paper provides a comprehensive review of flow characteristics at the crotch of VSLEs, with particular focus on the transition of shock interaction types and the variation of wall heat flux under different freestream Mach numbers and geometric configurations. The mechanisms governing shock transition, unsteady oscillations, hysteresis, and three-dimensional effects in VSLE flows are first examined. Subsequently, thermal protection strategies aimed at mitigating extreme heating loads are reviewed, emphasizing their relevance to practical engineering applications. Special attention is given to recent studies addressing thermochemical nonequilibrium effects on VSLE shock interactions, and the limitations of current research are critically assessed. Finally, perspectives for future investigations into hypersonic VSLE shock interactions are outlined, highlighting opportunities for advancing design and thermal management strategies.