不同波系配置的鼓包压缩面引起的激波/边界层干扰特性

Characteristic of shock wave/boundary layer interactions induced by bumps with different shock wave system arrangements

为了对不同波系配置的鼓包压缩面引起的锥形激波和来流边界层干扰的流场特性进行对比分析,分别以总偏转角相同的单锥、双锥和等熵锥等3种外锥流场为基准流场,在来流马赫数为2.0的条件下,采用流线追踪法设计了3种鼓包压缩面。在此基础上,采用数值仿真的方法对这3种鼓包压缩面在不同马赫数下的三维激波/边界层干扰流场进行了对比分析,结果表明:相比于单锥鼓包,双锥和等熵鼓包流场中的涡量集中区明显减小,且涡核处的涡量值也有所降低;对于双锥和等熵鼓包,由于受到后续波系的干扰,其表面流动的拓扑结构不再呈现出锥形相似性;双锥与等熵鼓包具有和单锥鼓包相同的边界层排移能力,且这一能力不随来流马赫数的变化而变化。此外,采用多波系配置能提高鼓包外压缩系统的总压恢复系数,波系数目越多,提升的程度就越大,且这一优势在高马赫数下更加明显。

In order to analyze the flow field characteristics of conical shock wave/boundary layer interactions induced by bumps with different shock wave system arrangements,three different bump compression surfaces were designed from the single cone,bipyramid and isentropic cone basic flow fields,respectively,by using the streamline tracing method.And such three basic flow fields had the same total deflection angle with the free stream Mach number 2.0.With the help of the numerical method,the three-dimensional shock wave/boundary layer interactions flow fields of such three bumps at different Mach numbers were compared.The results show that compared with single cone bump,the vorticity concentration regions in the flow fields of the bipyramid and isentropic bumps decrease evidently,the same with the vorticity values in the vortex core.Due to the interference of subsequent compression wave system,the flow patterns of the bipyramid and isentropic bumps don’t perform in the quasiconical similarity manner.Besides,the bipyramid and isentropicbumps have the same level of ability with the single cone bump in diverting the boundary layer,and such ability keeps invariant with the change of the free stream Mach number.Furthermore,the multi-wave system arrangement can improve the total pressure recovery coefficient of the bump external compression system.And the total pressure recovery coefficient will go higher with the increase of the wave number,particularly at high Mach number.