斜爆轰的多波结构及其稳定性研究进展

斜爆轰是气相爆轰物理的一个重要研究方向,在航空航天新型动力领域有重要的潜在应用价值.作为激波诱导的高速燃烧, 斜爆轰波可以简化为包含能量添加的间断面.然而, 斜爆轰流动中往往涉及激波、湍流等多种的流体力学现象,它们和燃烧放热耦合在一起, 导致流动和燃烧机理非常复杂. 一方面,斜爆轰波具有的多尺度和非线性的特征, 理论研究难以深入; 另一方面,爆轰波流场高温、高压、高速的特点, 又给实验研究带来了很大的困难.过去20年, 主要借助数值方法,研究者对斜爆轰波开展了系统的模拟和分析,在诸多方面取得了明显的进展.本文首先介绍了理想情况下的起爆区波系结构和波面稳定性研究进展;其次着眼于推进系统的问题,关注了非均匀来流效应以及斜爆轰波与稀疏波的作用;最后对未来的研究工作提出一些建议. 

Progress in multi-wave structure and stability of oblique detonations

Oblique detonation is an important direction in gaseous detonation physics and has great potential in the application of new-concept aeronautic and astronautic propulsion. As the fast combustion induced by shock, the oblique detonation wave could be simplified into a discontinuity with energy input. However, in oblique detonation flow, there concern several complicated fluid phenomena, such as shock wave and turbulence, which are coupled with the heat release and result in complicated flow and combustion mechanisms. A theoretical investigation is hard to be performed due to the characteristics of multi-scale and nonlinearity. Meanwhile, experimental investigation encounters the difficulties from measuring the flow fields of high temperature, high pressure, and high velocity. In the last two decades, the main progress of oblique detonation is achieved by numerical investigation through comprehensive simulation and analysis. First of all, the multi-wave structure of the initiation region and surface stability are introduced in the ideal inflow conditions. Then, derived from the application in engines, the effects of inflow inhomogeneity and interaction with expansion waves are studied and analyzed. Finally, some suggestions on future work are proposed and discussed.