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Related papers: New numerical solver for flows at various Mach num…

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Based on the Roe solver a new technique that allows to correctly represent low Mach number flows with a discretization of the compressible Euler equations was proposed in Miczek et al.: New numerical solver for flows at various mach…

Internal flows inside gravitationally stable astrophysical objects, such as the Sun, stars and compact stars are compressed and extremely subsonic. Such low Mach number flows are usually encountered when studying for example dynamo action…

Astrophysics · Physics 2007-12-24 A. Hujeirat , F. -K. Thielemann , J. Dusek , A. Nusser

Continuing on our previous work [ArXiv:1212.2644], we develop semi-implicit numerical methods for solving low Mach number fluctuating hydrodynamic equations appropriate for modeling diffusive mixing in isothermal mixtures of fluids with…

Numerical Analysis · Mathematics 2016-01-20 A. J. Nonaka , Y. Sun , J. B. Bell , A. Donev

Many astrophysical phenomena are highly subsonic, requiring specialized numerical methods suitable for long-time integration. In a series of earlier papers we described the development of MAESTRO, a low Mach number stellar hydrodynamics…

Instrumentation and Methods for Astrophysics · Physics 2015-05-18 A. Nonaka , A. S. Almgren , J. B. Bell , M. J. Lijewski , C. M. Malone , M. Zingale

Accurate simulations of flows in stellar interiors are crucial to improving our understanding of stellar structure and evolution. Because the typically slow flows are merely tiny perturbations on top of a close balance between gravity and…

Solar and Stellar Astrophysics · Physics 2021-08-18 P. V. F. Edelmann , L. Horst , J. P. Berberich , R. Andrassy , J. Higl , G. Leidi , C. Klingenberg , F. K. Roepke

We propose a low Mach number, Godunov-type finite volume scheme for the numerical solution of the compressible Euler equations of gas dynamics. The scheme combines Klein's non-stiff/stiff decomposition of the fluxes (J. Comput. Phys.…

Numerical Analysis · Mathematics 2014-12-05 Sebastian Noelle , Georgij Binev , K. R. Arun , Maria Lukáčová-Medviďová , Claus-Dieter Munz

We propose two novel two-state approximate Riemann solvers for the compressible Euler equations which are provably entropy dissipative and suitable for the simulation of low Mach numbers. What is new, is that one of our two methods in…

Numerical Analysis · Mathematics 2020-04-06 Jonas P. Berberich , Christian Klingenberg

While traditional approaches to prevent the carbuncle phenomenon in gas dynamics simulations increase the viscosity on entropy and shear waves near shocks, it was quite recently suggested to instead decrease the viscosity on the acoustic…

Numerical Analysis · Mathematics 2021-02-15 Friedemann Kemm

Roe scheme is known for its good performance in moderate-Mach-number flows. However, this scheme and its extended versions suffers from many disastrous problems, such as non-physical behavior, global cut-off, and checkerboard problems, for…

Computational Physics · Physics 2018-02-12 Xue-song Li , Xiao-dong Ren , Chun-wei Gu

Modelling long-time convective flows in the interiors of stars is extremely challenging using conventional compressible hydrodynamics codes due to the acoustic timestep limitation. Many of these flows are in the low Mach number regime,…

Computational Physics · Physics 2020-12-09 A. Harpole , D. Fan , M. P. Katz , A. J. Nonaka , D. E. Willcox , M. Zingale

In astrophysics and meteorology there exist numerous situations where flows exhibit small velocities compared to the sound speed. To overcome the stringent timestep restrictions posed by the predominantly used explicit methods for…

We introduce a low Mach number model for moist atmospheric flows that accurately incorporates reversible moist processes in flows whose features of interest occur on advective rather than acoustic time scales. Total water is used as a…

Atmospheric and Oceanic Physics · Physics 2015-05-08 Max Duarte , Ann Almgren , John Bell

A low-Mach-number flow, in the laminar regime, has intrinsically two characteristic spatial scales for a given time scale, or two characteristic temporal scales for a given spatial scale, and these dual scales are very different due to the…

Three asymptotic limits exist for the Euler equations at low Mach number - purely convective, purely acoustic, and mixed convective-acoustic. Standard collocated density-based numerical schemes for compressible flow are known to fail at low…

Fluid Dynamics · Physics 2023-03-24 J. Hope-Collins , L. di Mare

We present a new method for numerical hydrodynamics which uses a multidimensional generalisation of the Roe solver and operates on an unstructured triangular mesh. The main advantage over traditional methods based on Riemann solvers, which…

Instrumentation and Methods for Astrophysics · Physics 2017-06-28 Sijme-Jan Paardekooper

A simple HLLE-type scheme is proposed for all Mach number flows. In the proposed scheme, no extra wave structure is added in the HLLE scheme to resolve the shear wave while the contact wave is resolved by adding a wave structure similar to…

Fluid Dynamics · Physics 2022-07-15 A. Gogoi , J. C. Mandal

Convection is an important physical process in astrophysics well-studied using numerical simulations under the Boussinesq and/or anelastic approximations. However these approaches reach their limits when compressible effects are important…

Computational Physics · Physics 2019-05-01 T. Padioleau , P. Tremblin , E. Audit , P. Kestener , S. Kokh

In this paper, we justify the low Mach number limit of the steady irrotational Euler flows for the airfoil problem, which is the first result for the low Mach number limit of the steady Euler flows in an exterior domain. The uniform…

Analysis of PDEs · Mathematics 2019-01-15 Mingjie Li , Tian-Yi Wang , Wei Xiang

In this paper, we propose a new approach to singular limits of inviscid fluid flows based on the concept of dissipative measure-valued solutions. We show that dissipative measure-valued solutions of the compressible Euler equations converge…

Analysis of PDEs · Mathematics 2019-05-06 Eduard Feireisl , Christian Klingenberg , Simon Markfelder

We present a new approach to Eulerian computational fluid dynamics that is designed to work at high Mach numbers encountered in astrophysical hydrodynamic simulations. The Eulerian fluid conservation equations are solved in an adaptive…

Astrophysics · Physics 2009-11-10 Hy Trac , Ue-Li Pen
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