环形激波聚焦流场特性的数值研究

Numerical investigation on flow field characteristics of toroidal shock waves focusing in a cylindrical tube

针对环形激波聚焦过程产生的高温、高压特性,采用间断有限元方法模拟了环形激波在同轴圆柱形激波管内的聚焦流场特性。计算结果表明,采用间断有限元方法能够有效地捕捉激波聚焦过程形成的二次激波、涡环、三波交点和球面双马赫反射等主要流动特征。此外,通过改变环形管道内外半径对聚焦流场进行模拟发现,环形管道外径对中心轴线上聚焦峰值压力的大小和位置影响较小,环形管道内径对中心轴线上聚焦峰值压力的大小和位置影响较大。计算结果可以为工程应用提供一定的理论指导。

Aimed at high temperature and high pressure characteristics generated from toroidal shock wave focusing,a discontinuous finite element method was used to numerically simulate toroidal shock wave focusing in a co-axis cylindrical tube.The simulated results indicate that the discontinuous finite element method can capture efficiently the complicated flow-field wave structures which include secondary shock wave,vortex ring,triple point and spherical double Mach reflection formed during shock waves propagating in the co-axial cylindrical shock tube.And from the simulated results,it can be found that the inner radius of the toroidal pipeline can affect markedly the value and location of the peak pressure along the axis line,and the outer radius of the toroidal pipeline plays a weak role.The investigated results can provide a theoretical guide for engineering application.