温度扰动对ODW结构影响的数值模拟

利用二维非稳态无黏可压欧拉方程模拟得到了能够稳定自持的斜爆震波（ODW）结构，在某时刻从进口边界施加一温度的瞬间变化（分别为下降100 K、上升100 K），从而得到一次温度扰动。模拟结果表明，ODW结构能够顺利过渡，但扰动传播过后，ODW的内部不稳定性被进一步被释放，胞格结构更加清晰；结合定量和定性分析发现，扰动主要以激波、膨胀波和弱压缩波3种形式在燃烧室内传播；对比2种扰动下的结果得出，3种波在爆震区内传播过程中的位置分布相同，但在爆燃区内却完全相反，造成这种结果的主要原因是2种扰动引发的弱压缩波的强度不同，从而对ODW结构调整所起到的作用也存在很大区别；在温降扰动下，3种波沿壁面向下游传播，其中激波会呈现出弓形激波、马赫反射、规则反射和近乎垂直于壁面的正激波4种形态，而在温升扰动下，3种波沿ODW面向下游传播，传播形态也较为稳定。

Numerical simulation of influence of temperature disturbance on oblique detonation wave structure

2D Euler equations were used for the numerical simulation of the influence of temperature disturbance on oblique detonation waves (ODW) in an oblique detonation combustion chamber. Instantaneous variation of temperature was introduced from the inlet as the disturbance by increasing and decreasing 100 K respectively. The simulation results show that the ODW can adjust with the temperature disturbance and the transition progress is smooth enough. But the inherent instability of ODW is found to be further released by disturbance and cell structure is clearer. The existing form of disturbance was researched quantitatively and qualitatively, which is the complex of shock wave, expansion wave and weak compression wave. Comparison between the results from two kinds of disturbance was conducted, which demonstrates that the distribution of waves is basically the same in detonation zone, while reversed in deflagration zone. It is caused by the difference in the strength of weak compression wave in two cases,which effects the ODW structure enormously in consequence. Furthermore, at decreasing temperature, the complex of three kinds of wave propagates downstream along the ramp and shock wave appears in four types of form which are bow-like shock, Mach reflection, regular reflection and normal shock nearly vertical to the ramp. There is an enormous bifurcation at increasing temperature, where the waves propagate along the surface of ODW and the form of waves remains stable relatively.