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arXiv 2003.10695math.NAcs.NA
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高速可压缩流的新型、简单和鲁棒的接触间断捕获格式

Novel, simple and robust contact-discontinuity capturing schemes for high speed compressible flows

Ramesh Kolluru, N. Venkata Raghavendra, S. V. Raghurama Rao, G. N. Sekha

摘要:

可压缩流体流动的控制方程中的非线性对流项本质上是双曲的,并且对于建模和数值模拟是非平凡的。许多数值方法在过去的几十年中已经开发了用于此目的,通常是基于黎曼解算子,这是强烈依赖于基本的本征结构的控制方程。本工作的目的是开发简单的算法,不依赖于特征结构,但可以很容易地处理双曲部分。具有智能扩散机制的中心方案适合于此目的。为解决数值扩散问题,提出了满足Rankine-Hugoniot(RH)条件和广义Riemann不变量的基本思想。两个这样有趣的算法,准确地捕捉网格对齐的稳定接触不连续性,但有足够的数值扩散,以避免数值激波不稳定性。这两种算法都是强大的,在避免冲击不稳定性,除了准确捕捉接触不连续性,不需要波的速度校正,是独立的特征结构的基本双曲部分的系统。

英文摘要:

The nonlinear convection terms in the governing equations of compressible fluid flows are hyperbolic in nature and are nontrivial for modelling and numerical simulation. Many numerical methods have been developed in the last few decades for this purpose and are typically based on Riemann solvers, which are strongly dependent on the underlying eigen-structure of the governing equations. Objective of the present work is to develop simple algorithms which are not dependent on the eigen-structure and yet can tackle easily the hyperbolic parts. Central schemes with smart diffusion mechanisms are apt for this purpose. For fixing the numerical diffusion, the basic ideas of satisfying the Rankine-Hugoniot (RH) conditions along with generalized Riemann invariants are proposed. Two such interesting algorithms are presented, which capture grid-aligned steady contact discontinuities exactly and yet have sufficient numerical diffusion to avoid numerical shock instabilities. Both the algorithms presented are robust in avoiding shock instabilities, apart from being accurate in capturing contact discontinuities, do not need wave speed corrections and are independent of eigen-strutures of the underlying hyperbolic parts of the systems.

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。

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