激波与障碍物作用加速衰减的数值研究

INVESTIGATIONS INTO THE ACCELERATING ATTENUATION OF SHOCK WAVES BY OBSTACLES

强激波在管道内传播时与障碍物作用会发生绕射和反射,同时还会生成膨胀波等复杂波系结构。初步研究表明,若障碍物形状合适,则可导致激波强度衰减,但其衰减程度与障碍物形状的关系则仍待进一步研究。该文利用高阶数值格式结合沉浸边界法(IBM)以及自适应网格加密(AMR)技术,对激波在管道内与不同迎风面角度的障碍物作用过程进行了数值模拟,对激波与障碍物作用衰减的机理进行了分析,并对三种障碍物对激波衰减的效果进行了对比分析,结果表明,迎风面斜率为负的障碍物相对于其他两种障碍物具有最佳激波衰减效果。另外,与目前隧道中常用的壁面为矩形障碍物的模型为算例进行了对比,结果表明,该三角形模型比矩形障碍物具有更显著的激波衰减效果。

When a strong shock wave interacts with obstacles in a tube, some complex physical phenomena, such as shock wave reflection and diffraction etc., may occur, which generates expansive waves and many other complex wave structures. Previous research has shown that, if the shape of the obstacle is appropriate, the intensity of the shock wave may be attenuated. However, the relationship between the attenuation magnitude of shock waves and obstacles requires further clarification. In this study, numerical investigation of the interaction of shock waves with three triangular obstacles of different slopes of windward sides were carried out using high order numerical schemes, i.e. the immersed boundary method(IBM) and the adaptive mesh refinement(AMR) technology. Results show that, obstacles with a negative windward side slope have the most favourable effects on shock wave attenuation when compared to those with positive and zero slopes. In addition, triangular obstacles have shown to impose a more significant attenuation effect on shock waves than the commonly-used rectangular obstacles in tunnels.