Transitional wave configurations between Type Ⅲ and Type Ⅳ oblique-shock/bow-shock interactions

The interactions of oblique/bow shock waves are the key flow phenomena restricting the design and aerothermodynamic performance of high-speed vehicles. Type Ⅲ and Type Ⅳ Shock/Shock Interactions(SSIs) have been extensively investigated, as such interactions can induce abnormal aerodynamic heating problems in hypersonic flows of vehicles. The transition process between these two distinct types of shock/shock interactions remains unclear. In the present study, a subclass of shock/shock interaction configuration is revealed and defined as Type Ⅲa. Type Ⅲa interaction can induce much more severe aerodynamic heating than a Type Ⅳ interaction which was ever reported to be the most serious in literature. The intense aerodynamic heating observed in this configuration highlights a new design point for the thermal protection system of hypersonic vehicles. A secondary Mach interaction between shock waves in the supersonic flow path of a Type Ⅲ configuration is demonstrated to be the primary mechanism for such a subclass of shock/shock interaction configuration.