TYPE Ⅱ HYPERSONIC SHOCK WAVE INTERACTION ON A SWEPT-FORWARD FIN

An investigation of swept-forward fin shock interactions is conducted theoretically and numerically, focusing on the effects of wedge angle and swept-forward angle on the flow pattern and heat flux distribution of type II interaction. Numerical results indicate that three types of jets are observed in the downstream flow pattern of the type II interaction on the symmetry plane: supersonic, subsonic, and transonic jets. Notably, an extremely high heat flux which is caused by a supersonic jet is observed in the case where the wedge angle is 20°. In contrast, for cases with transonic and subsonic jets, the peak heat flux is significantly lower than that of the supersonic jet, due to the weakening of the wall strike effect. The study demonstrates that within a specific range of geometric parameters, increasing the wedge angle does not necessarily result in a corresponding increase in heat flux. Instead, a larger wedge angle can promote the transition of the jet from supersonic to subsonic speeds, thus leading to a reduction in heat flux. This finding challenges conventional assumptions and offers potential pathways for controlling aerodynamic heating in high-speed flows. The conditions for the generation of subsonic and supersonic jets are theoretically analyzed under the assumption of local uniform flow in the interference region and numerically verified with a freestream Mach number of 6.36. Theoretical analysis indicates that subsonic and transonic jets, which result in lower heat flux peaks, are generally present within a wide range of parameters. For a given freestream Mach number, larger wedge angles are more likely to produce subsonic or transonic jets. Due to the simplifications inherent in the uniform flow assumption, the critical wedge angles predicted for the formation of subsonic and supersonic jets were found to be slightly higher than those obtained from CFD simulations, with a discrepancy of approximately 1°.