INVESTIGATION ON THE HEAT FLUX REDUCTION CHARACTERISTICS OF THE LOCAL BULGES IN THE V-SHAPED BLUNT LEADING EDGE

Complex shock interaction structures and severe aerothermal heating loads are usually encountered on the lips of the three-dimensional inward-turning inlet, which seriously threatens the performance and safety of the hypersonic flight vehicle. The passive heat flux reduction scheme with the local bulge is designed based on the simplified model of the V-shaped lip, the V-shaped blunt leading edge. By performing numerical simulations, the heat flux reduction ability and the heat flux reduction principle of the local bulge scheme are researched at Mach number of 6.0. Then, the key design parameters of the scheme, which include the position, the height, and the width of the local bulge, are preliminarily optimized. Finally, the applicability of the optimized scheme in terms of attack angle, sideslip angle, and Mach number is analyzed. The oblique shocks formed at the edges of the upstream bulge interact with the transmitted shock formed by the primary Mach reflection structure, which can weaken the intensity of the transmitted shock impinging on the wall and achieve the purpose of heat flux reduction. By changing the collision angle of the supersonic jets, the stagnation bulge can reduce the collision intensity of the jets and achieve the purpose of heat flux reduction as well. The heat flux reduction ability of the original local bulge scheme is about 37.75%. After preliminarily optimizing the key design parameters of the local bulge scheme, the heat flux reduction ability of the optimized local bulge scheme can be increased to 44.60%. The optimized scheme under design condition has excellent applicability of attack angle. Meanwhile, the optimized scheme with changeable height can be well applied to the flow with sideslip angles or high freestream Mach numbers. Within the research scope of this work, the heat flux reduction ability of the optimized local bulge scheme with changeable height is higher than 20%.