Computational simulations of microscale shock–vortex interaction using a mixed discontinuous Galerkin method
Computational simulations of microscale shock–vortex interaction using a mixed discontinuous Galerkin method
复制标题
DOI：
10.1016/j.compfluid.2014.09.027
复制
发表时间：
2014-12
影响因子：
2.8
通讯作者：
H. Xiao;R. Myong
中科院分区：
文献类型：
--
作者：
H. Xiao;R. Myong
本文通过求解非牛顿本构关系的守恒律方程，对氩气微尺度激波-涡旋相互作用的物理过程进行了深入的研究。为了数值求解粘性应力和热流的守恒律和相关的隐式二阶本构方程，发展了一种混合间断Galerkin（DG）格式。在热非平衡条件下，微尺度激波与涡的相互作用具有三个主要特征：宏观近平衡条件下的四极声波结构不存在;强相互作用时耗散率增大;弱相互作用时涡此外，我们还发现，在高激波或涡马赫数下，强的激波-涡相互作用会引起涡拟能的增加。我们还发现粘性效应是占主导地位的净涡产生。在激波和涡参数中，激波马赫数、涡马赫数和涡尺寸对涡的变形和相互作用的强度起着关键作用，而涡的变形和相互作用的强度又决定着相互作用过程中由于粘性效应而引起的涡量的演化、耗散率的变化和涡拟能的增减。
This study extensively investigates the physics of microscale shock–vortex interaction of argon gas by solving conservation laws with non-Newtonian constitutive relations. In order to solve the conservation laws and associated implicit type second-order constitutive equations of viscous stress and heat flux numerically, a mixed discontinuous Galerkin (DG) formulation is developed. Three major characteristics are found in the microscale shock–vortex interaction in thermal nonequilibrium: the absence of quadrupolar acoustic wave structure, which is the major feature in macroscale near-equilibrium; the increase in the dissipation rate during the strong interaction; and the decrease in enstrophy during the weak interaction. Moreover, we show that the strong shock–vortex interaction in high shock or vortex Mach numbers can cause an increase in enstrophy. We also find the viscous effect to be dominant in the net vorticity generation. Among shock and vortex parameters, the shock Mach number, vortex Mach number and vortex size turn out to play a critical role in the deformation of the vortex and the strength of interaction, which in turn govern the evolution of vorticity due to the viscous effects, the change in the dissipation rate and the increase or decrease in enstrophy during the interaction.