高超声速二元进气道脉冲起动双波结构的理论与数值研究

Theoretical and Numerical Study of Double Shock Structure During 2D Hypersonic Inlet Pulse-Starting Process

为了研究高超声速进气道的脉冲起动特性,对二元高超声速进气道在脉冲风洞中流场建立过程进行了数值模拟,并根据运动激波关系式建立了双波结构数学模型,分析了进气道脉冲起动过程中双波结构的产生及传播过程。研究表明通过理论计算得到的双波结构气动参数与仿真结果基本一致。结合仿真发现进气道脉冲起动过程流场的主要特征包括:运动激波与斜激波相交、激波/边界层相互干扰以及分离包的空间位置和自身体积变化、进气道自起动过程等。另外结合双波结构计算模型,通过仿真研究了影响双波结构流动参数及影响进气道脉冲起动特性的因素,发现初始条件影响进气道的脉冲起动特性主要是通过改变双波结构的强度实现的。

In order to investigate the pulse-starting characteristics of hypersonic inlet, simplified numer- ical simulation of a 2D hypersonic inlet starting process in shock tunnel has been performed. According to the basic moving shock relations, a mathematical model has been set up to analyze the appearance and promulgating process of the double shock. The parameters of double shock calculated by the mathematical model match numerical simulation well. The CFD results show that the flow-field characteristics during the inlet pulse-starting process mainly include the interaction of moving shock and oblique shockwave, shock- wave/boundary layer interactions, separation bubble transformation on spatial position and itself volume, the self-starting process as well. In addition, some possible factors that may influence the double shock and the pulse-starting ability of 2D hypersonic inlet have been analyzed. The results reveal that these factors take effect by transforming the strength of double shock.