为了研究激波与转捩边界层的干扰机理，采用直接数值模拟方法对来流马赫数2.9，24o压缩拐角内激波与转捩边界层的相互作用进行了系统地研究。考察了转捩干扰下压缩拐角内拟序涡结构、分离泡形态和激波波系结构等的典型特征。比较了转捩干扰与湍流干扰流动结构的差异，并分析了造成差异的原因。研究了拐角内转捩边界层的演化特性，探讨了转捩干扰下脉动峰值压力和峰值摩阻的分布规律及形成机制。研究表明：相较于湍流干扰，转捩干扰下拐角内拟序涡结构沿展向非均匀分布，两侧发卡涡串的展向挤压使得分离区起始点以V字型分布，且分离激波沿展向以破碎状态为主，激波脚呈现多层结构。拐角内的干扰作用急剧加速了边界层的转捩过程。转捩干扰下的拐角内峰值脉动压力以单峰结构出现在分离区的下游，同时干扰区内的强湍动能和高雷诺剪切应力使得其局部峰值摩阻系数要高于湍流干扰。

A direct numerical simulation of shock wave and transitional boundary layer interaction for a 24 deg compression ramp at Mach 2.9 is conducted. The intricate flow phenomena in the ramp-corner, including coherent vortex structures, separation bubble characteristics and shock wave behaviors, have been studied systematically. The DNS results of transitional interaction are compared with the corresponding turbulent interaction and the reasons for the differences are analyzed. The evolution of the transitional boundary layer in the ramp is researched. The fluctuation of wall pressure and distribution of skin-friction coefficient in the transitional interaction are investigated in detail. Results indicate that the distribution of coherent vortex structures is non-uniform in the spanwise direction and the separation bubble is reduced to a V-shape by the mutual interactions of the hairpin vortices chains. The shock fronts are destroyed badly and even break down by the interaction. The multiple layer of shock foots is observed obviously. The interactions rapidly accelerate the evolution of transition and greatly amplify the intensity of fluctuations. The peak of wall pressure fluctuations appears with single-peak structure at the downstream of separation region. And the overshoot of skin friction induced by transitional interaction is explained by the strong Reynolds shear stress and high turbulent kinetic energy.