斜爆轰波的波角和法向速度-曲率关系初探

为研究斜劈诱导斜爆轰波的波阵面弯曲效应，以期为斜爆轰的不稳定性及其演化规律提供新的见解，基于加权本质无振荡（WENO）格式空间离散和附加Runge-Kutta方法时间离散的求解器，针对不同的化学反应参数（释热量、放热速率和化学反应区参考长度）条件，开展斜爆轰波的数值计算研究。结果表明斜爆轰波沿波阵面的波角变化可分为3个区域：区域I，波角平滑减小；区域II，波角跃升后衰减；区域III，波角有规律振荡。波阵面法向速度-曲率关系在区域I呈现准垂直直线变化趋势，并伴随着爆轰波强度的不断衰减；在区域III则呈现出"D"形曲线，即由极曲线段、光滑水平变化段和拟线性变化段组成，为类胞格结构的周期性演变；区域II可认为是以上两个区域特征的耦合。不同的化学反应参数对斜爆轰波波阵面的弯曲效应影响存在较大差别。

Preliminary study on wave angle and normal velocity-curvature relation of oblique detonation wave

To provide an insight into the instability of oblique detonation waves and the evolution law of cellular-like structures, a numerical study on the curvature effect of wedge induced oblique detonation waves is conducted with different chemical kinetic parameters (heat release quality, heat release ratio and reference lengths of chemical reaction zones). The solver based on the Weighted Essentially Non-Oscillatory (WENO) scheme processed spatial discretization and additive Runge-Kutta method processed time discretization is used here. The numerical results show that the trend of the wave angles along the oblique detonation wave front can be divided into three regions: Region I, where the wave angles decrease smoothly; Region II, in which the wave angles experience a steep increase first and followed then by decay; Region III, where the wave angles exhibit an oscillation. The normal velocity-curvature relation in Region I is a quasi-vertical line with the flow field being a decaying oblique detonation wave. A "D" shaped curve consisting of a polar line, a smooth horizon curve and a quasilinear curve can be found in the normal velocity-curvature diagram for Region III, where a cycle evolution of cellular-like structures occurs in the front. Region II is deemed as the coupling effect of Regions I and III. Different chemical kinetic parameters bring diverse effects on the oblique detonation wave front.