Effects of corner bluntness on the flow characteristics of the double-cone in non-equilibrium flow

Shock wave/boundary layer interaction (SWBLI) and shock/shock interaction (SSI) have drawn considerable focus due to their potential to cause severe aerodynamic heating. Research (Ai et al., 2024) demonstrated that within a high-enthalpy freestream environment, the 25°/55° double-cone flow exhibits critical coupling between SWBLI and SSI when considering high-temperature effects. This study extends the investigation into the effects of corner bluntness on double-cone flow characteristics, employing numerical simulations and the shock polar method. The results highlight a critical fillet radius beyond which the separation length decreases inversely with increasing bluntness, and below which it stabilizes at a larger value. As bluntness decreases, four distinct flow states are identified: weak interaction state, transition state, strong interaction state, and separation state. The separation state features a complex interaction of Type VI SSI, Type IV SSI, and SWBLI. Modest bluntness counterintuitively amplifies thermal loads, while substantial bluntness reduces the peak heat flux by 54.4%. Thermodynamic non-equilibrium downstream of the bow shock remains insensitive to bluntness, yet air dissociation and heat transfer correlate strongly with flow state evolution. Parameter evolution is further analyzed along wall-normal profiles at load extrema and streamlines through the triple point across bluntness variations. These insights hold significant implications for the industrial design and manufacturing of hypersonic vehicles.