高超声速椭圆锥短轴流向涡处的全局稳定性研究

高超声速椭圆锥短轴处存在流向涡，这里的边界层全局稳定性问题，既与工程实际密切相关，又有重要的科学意义。本项目拟用数值计算的方法得到基本流，再在短轴处做二维全局稳定性分析。拟通过对稳定性四方面特性的研究，以期对高超声速椭圆锥短轴流向涡处的全局稳定性有系统的、深入的认识。第一，确认短轴处是否有不稳定的内模态。第二，研究正弦型外模态、余弦型外模态和内模态是否有相同的物理本质，即是否都由无粘的拐点不稳定性所引起。第三，研究每个不稳定模态沿流向的变化。第四，确认不同长短轴比对稳定性的影响。

Streamwise vortices are formed near the minor-axis meridian of hypersonic elliptic cone. The global instability on the streamwise vortices plays a key role in engineering problems, and is of great importance to science development as well. In the present project, we plane to do BiGlobal instability analysis on the base flow near minor-axis meridian, which is obtained by numerical calculation. The present project aims to develop and deepen our understanding of the global instability on streamwise vortices near minor-axis meridian of hypersonic elliptic cone by investigating four aspects of it. Firstly, it is expected to confirm whether there is unstable inner mode. Secondly, it is expected to investigate whether sinuous type outer mode, varicose type outer mode, and inner mode have the same physical essence, i.e. all these unstable modes are caused by inviscid inflection instability. Thirdly, it is expected to study how each unstable mode evolves in streamwise direction. Fourthly, it is expected to confirm the effects of aspect ratio on instability.