气体体积粘性对二维环形激波聚焦的影响

Numerical Investigation of Bulk Viscosity Effect on Two-dimensional Toroidal Shock Wave Focusing

基于体积粘性系数ζ的分子运动论和连续介质理论,对二维环形激波聚焦(马赫数Ma=2.0)的体积粘性效应进行数值研究,结果表明:对于热完全气体,体积粘性使得激波汇聚中心点处的压力减小、温度增加、密度减小,聚焦点物理参数的改变量分别可达20%、10%、30%,体积粘性效应对环形激波聚焦的影响是不可忽略的;与转动模态相比,在振动模态下环形激波聚焦的体积粘性效应更为明显,因为激波聚焦点附近的体积粘性应力ζΔ·V与热力学压力p达到同一数量级,从而显著改变了流动参数.

With kinetic and continuum theories of bulk viscosity coefficient, bulk-viscosity effect on two-dimensional toroidal shockwave focus （Mach number Ma = 2. 0） is studied numerically. It shows that bulk-viscosity effect on toroidal shock-wave focusing is not negligible for perfect gases. Due to bulk viscous effect in compressible flows, pressure, temperature and density at the central focus perform 20% reduction, 10% increase and 30% reduction, respectively. Compared with rotational mode, shock wave focusing present obvious bulk-viscosity effect in vibrational mode, since bulk viscous stress has same order of magnitude with thermodynamic pressure.