An experimental and numerical study was carried out to investigate the effect of leading edge bluntness on the flowfield characteristics of a Mach 6 scramjet inlet. The numerical study was performed using Ansys Fluent 18.0 software. A steady two-dimensional Reynolds-Averaged Navier–Stokes simulation was carried out using $k\text{-}\epsilon$-Re-Normalisation Group model for a sharp edge and leading edge with bluntness of 0.5 and 1 mm (ramp and cowl tip). Significant changes in the flowfield characteristics and parameters were observed for a blunt leading edge compared to the sharp leading edge case. The experimental campaign was carried out in the Mach 6 S1 Hypersonic Ludwieg Tunnel to validate the numerical results, and a good match was observed up to the separation bubble, and deviation in the reattachment is observed. Furthermore, the unsteadiness associated with the shockwave–boundary-layer interaction region inside the isolator was studied for the sharp and blunt leading edge cases. It was observed that changing the leading edge bluntness modifies the flowfield oscillations, separation bubbles, shear layer oscillations, etc.

进行了实验和数值研究，以研究前缘钝度对马赫 6 超燃冲压发动机入口流场特性的影响。数值研究是使用 Ansys Fluent 18.0 软件进行的。使用以下方法进行稳定二维雷诺平均纳维-斯托克斯模拟$k\text{-}\epsilon$-重新归一化组模型，用于锐边和钝度为 0.5 毫米和 1 毫米的前缘（坡道和整流罩尖端）。与尖锐前缘的情况相比，观察到钝前缘的流场特性和参数的显着变化。实验在马赫 6 S1 高超音速路德维格隧道中进行，以验证数值结果，观察到分离气泡的良好匹配，并观察到重新附着的偏差。此外，针对尖锐和钝的前缘情况，研究了与隔离器内部冲击波-边界层相互作用区域相关的不稳定性。据观察，改变前缘钝度会改变流场振荡、分离气泡、剪切层振荡等。