In this paper, we propose a high order semi-implicit well-balanced finite difference scheme for all Mach Euler equations with a gravitational source term. To obtain the asymptotic preserving property, we start from the conservative form of full compressible Euler equations and add the evolution equation of the perturbation of potential temperature. The resulting system is then split into a (non-stiff) nonlinear low dynamic material wave to be treated explicitly, and (stiff) fast acoustic and gravity waves to be treated implicitly. With the aid of explicit time evolution for the perturbation of potential temperature, we design a novel well-balanced finite difference WENO scheme for the conservative variables, which can be proven to be both asymptotic preserving and asymptotically accurate in the incompressible limit. Extensive numerical experiments were provided to validate these properties.
翻译:在本文中,我们提出了一个针对所有马赫尤勒方程式的高顺序半隐含的平衡的有限差异方案,并有一个引力源术语。为了获得无症状保护属性,我们从完全压缩的埃勒方程式的保守形式开始,加上潜在温度扰动的进化方程式。由此形成的系统随后被分割成一个非线性、非线性、低动态物质波,需要明确处理,以及(stiff)快速声波和重力波,需要暗中处理。在潜在温度扰动的明确时间演化帮助下,我们为保守变量设计了一个新颖的平衡的有限差异WENO方案,这可以证明既无症状保护,又在不可压缩的限度内是无症状准确的。为了验证这些属性,提供了广泛的数字实验。