近年来，研究者越来越重视条带失稳在高超声速边界层转捩中的作用，普遍采用最优增长理论描述瞬态增长的条带。事实上，最优增长理论未考虑条带的感受性过程，无法描述真实条带的增长。本项目拟选用我们前期实验及理论研究中采用的钝平板模型，研究高超声速边界层中条带对自由流扰动的感受性机理。项目将建立三维自由流扰动与斜激波的线性作用模型，用于确定自由流扰动在弓形激波后形成的新扰动的特征。采用谐波型线性化Navier-Stokes方法，高效模拟弓形激波后的扰动在高超声速边界层中的响应及条带的激发过程；确定能够高效地激发高超声速边界层中条带的自由流扰动类型及扰动参数组合；确定自由流扰动进入高超声速边界层并激发条带的主导流动区域及该区域的流动特征。

In recent years, researchers have paid more and more attention to the role of streak instability in transition of hypersonic boundary layers, and generally adopted the optimal growth theory to describe transient growth streaks. In fact, the optimal growth theory cannot correctly describe the evolution of realistic streaks, because the receptivity of streaks is not considered. In this project, the blunt plate model used in our previous experimental and theoretical researches is selected to study the receptivity of streaks to freestream perturbations in hypersonic boundary layer. The project will establish a model describing the linear interaction between three-dimensional free stream perturbations and oblique shock wave. The model is used to determine the characteristics of the new perturbations formed by freestream perturbations behind the bow shock wave. The harmonic linearized Navier-Stokes (HLNS) method is used to efficiently simulate the response of the perturbations behind bow shock wave in hypersonic boundary layer and the excitation process of streaks. The types and parameter combinations of freestream perturbations that can effectively excite the streaks in the hypersonic boundary layer will be determined. We will also determine the dominant flow region and the flow characteristics in the region where the freestream perturbations enter the hypersonic boundary layer and excite streaks.