arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2008.01789math.NAcs.NAphysics.comp-ph
收藏

全马赫数下三维斯托克斯方程的高阶压力基半隐式IMEX格式

High order pressure-based semi-implicit IMEX schemes for the 3D Navier-Stokes equations at all Mach numbers

Walter Boscheri, Lorenzo Pareschi

摘要:

本文旨在发展一个高阶压力基解,用于求解三维可压缩Navier-Stokes方程组在所有马赫数下的解。我们提出了一个细胞为中心的离散化的控制方程,分裂成一个快速和一个缓慢的规模的部分,这是隐式和显式处理的通量,分别。提出了一种新的半隐式离散的动能以及焓通量的能量方程,从而避免了任何需要迭代求解。隐式离散产生一个关于压力的椭圆型方程,该方程可以求解理想气体和一般方程。在非线性状态方程的情况下,采用嵌套牛顿法求解压力的轻度非线性系统。隐式显式(IMEX)的时间步进,而一种新的CWENO技术有效地实现了一个维度的方式开发实现显式对流和粘性通量的离散化在空间上的高阶。一个无求积的有限体积求解器,然后推导出高阶近似的数值通量。最后采用适当精度的无耗散中心格式对隐式项进行数值逼近。因此,CFL型的稳定性条件的最大容许时间步长是只基于流体的速度,而不是声速,使新的计划工作均匀的所有马赫数。收敛性和鲁棒性所提出的方法进行评估,通过广泛的基准问题,涉及低和高马赫数制度,以及无粘和粘性流。

英文摘要:

This article aims at developing a high order pressure-based solver for the solution of the 3D compressible Navier-Stokes system at all Mach numbers. We propose a cell-centered discretization of the governing equations that splits the fluxes into a fast and a slow scale part, that are treated implicitly and explicitly, respectively. A novel semi-implicit discretization is proposed for the kinetic energy as well as the enthalpy fluxes in the energy equation, hence avoiding any need of iterative solvers. The implicit discretization yields an elliptic equation on the pressure that can be solved for both ideal gas and general equation of state (EOS). A nested Newton method is used to solve the mildly nonlinear system for the pressure in case of nonlinear EOS. High order in time is granted by implicit-explicit (IMEX) time stepping, whereas a novel CWENO technique efficiently implemented in a dimension-by-dimension manner is developed for achieving high order in space for the discretization of explicit convective and viscous fluxes. A quadrature-free finite volume solver is then derived for the high order approximation of numerical fluxes. Central schemes with no dissipation of suitable order of accuracy are finally employed for the numerical approximation of the implicit terms. Consequently, the CFL-type stability condition on the maximum admissible time step is based only on the fluid velocity and not on the sound speed, so that the novel schemes work uniformly for all Mach numbers. Convergence and robustness of the proposed method are assessed through a wide set of benchmark problems involving low and high Mach number regimes, as well as inviscid and viscous flows.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑