English
Related papers

Related papers: Numerical Bow Shock Instabilities in Inert Polyato…

200 papers

Elastic turbulence is a chaotic regime that emerges in polymer solutions at low Reynolds numbers. A common way to ensure stability in numerical simulations of polymer solutions is to add artificially large polymer-stress diffusion. In order…

Fluid Dynamics · Physics 2019-05-22 Anupam Gupta , Dario Vincenzi

In this paper we show results of numerical simulations for the turbulence in the interstellar medium. These results were obtained using a Riemann solver-free numerical scheme for high-Mach number hyperbolic equations. Here we especially…

Astrophysics of Galaxies · Physics 2011-02-11 R. Kissmann , J. Kleimann , H. Fichtner , R. Grauer

The shock instability problem commonly arises in flow simulations involving strong shocks, particularly when employing high-order schemes, limiting their applications in hypersonic flow simulations. This study focuses on exploring the…

Numerical Analysis · Mathematics 2023-08-08 Weijie Ren , Wenjia Xie , Ye Zhang , Hang Yu , Zhengyu Tian

In this paper, we show that the quasi-one-dimensional flow of an ideal inviscid fluid in a corrugated pipe is parametrically unstable in certain frequency bands. First-order perturbation theory is used to analyze the stability of the flow,…

Fluid Dynamics · Physics 2021-02-09 Nikita V. Bykov

Parker instability arises from the presence of magnetic fields in a plasma in a gravitational field such as the interstellar medium (ISM), wherein the magnetic buoyant pressure expels the gas and causes the gas to move along the field…

High Energy Astrophysical Phenomena · Physics 2011-09-07 Chih-Yueh Wang , Ying-Yi Lo , Chung-Ming Ko

Supernova remnant (SNR) blast shells can reach the flow speed $v_s = 0.1 c$ and shocks form at its front. Instabilities driven by shock-reflected ion beams heat the plasma in the foreshock, which may inject particles into diffusive…

Astrophysics · Physics 2017-08-02 M. E. Dieckmann , A. Meli , P. K. Shukla , L. O. C. Drury , A. Mastichiadis

A case of two interpenetrating, cold and quasi-neutral ion-electron plasmas is investigated with the multi-fluid approach. We consider that one plasma flows quasi-parallel to the lines of a background magnetic field embedded in another…

High Energy Astrophysical Phenomena · Physics 2019-03-19 Vladimir Zekovic

Context. While the shapes of many observed bow shocks can be reproduced by simple astrosphere models, more elaborate approaches have recently been used to explain differing observable structures. Aims. By placing perturbations of an…

Astrophysics of Galaxies · Physics 2021-06-02 Lennart R. Baalmann , Klaus Scherer , Jens Kleimann , Horst Fichtner , Dominik J. Bomans , Kerstin Weis

When the pressure of particles accelerated at shock waves is no longer negligible compared to the kinetic pressure of the gas, the linear theory of diffusive shock acceleration breaks down. This is expected in particular when the shock…

High Energy Astrophysical Phenomena · Physics 2021-12-22 Thibault Vieu , Stefano Gabici , Vincent Tatischeff

We investigate the dynamics of a Bose-Einstein condensate in a progressively bended three dimensional cigar shaped potential. The interplay between geometry and nonlinearity is considered. At high curvature, topological localization occurs…

Quantum Gases · Physics 2016-04-05 Claudio Conti

Brenner has recently proposed modifications to the Navier-Stokes equations that are based on theoretical arguments but supported only by experiments having a fairly limited range. These modifications relate to a diffusion of fluid volume…

Fluid Dynamics · Physics 2009-11-13 Christopher J. Greenshields , Jason M. Reese

In recent works, we proposed a hypothesis, according to which turbulence in gases is created by the mean field effect of an intermolecular potential. We discovered that, in a numerically simulated inertial flow, turbulent solutions indeed…

Fluid Dynamics · Physics 2023-10-18 Rafail V. Abramov

The processes of merging and splitting dilute-gas Bose-Einstein condensates are studied in the nonadiabatic, high-density regime. Rich dynamics are found. Depending on the experimental parameters, uniform soliton trains containing more than…

Other Condensed Matter · Physics 2009-11-13 J. J. Chang , P. Engels , M. A. Hoefer

This paper is devoted to studying the inflow problem for an ideal polytropic model with non-viscous gas in one-dimensional half space. We showed the existence of the boundary layer in different areas. By employing the energy method, we also…

Analysis of PDEs · Mathematics 2018-06-01 Meichen Hou , Lili Fan

We extend the linear analysis of the drag instability in a 1D perpendicular isothermal C-shock by Gu & Chen to 2D perpendicular and oblique C-shocks in the typical environment of star-forming clouds. Simplified dispersion relations are…

Solar and Stellar Astrophysics · Physics 2021-06-21 Pin-Gao Gu

Context. Relativistic jets from Active Galactic Nuclei are observed to be collimated on the parsec scale. When the pressure between the jet and the ambient medium is mismatched, recollimation shocks and rarefaction shocks are formed.…

High Energy Astrophysical Phenomena · Physics 2025-01-15 Xu-Fan Hu , Yosuke Mizuno , Christian M. Fromm

Quantum droplets are ultradilute liquid states which emerge from the competitive interplay of two Hamiltonian terms, the mean-field energy and beyond-mean-field correction, in a weakly interacting binary Bose gas. We relate the formation of…

With a help of hydrodynamical models, we explore fundamental modes of gas flow in central parts of a galaxy potential with non-axisymmetric perturbations of various strengths. Our grid-based algorithm allows us to get a detailed picture of…

Astrophysics · Physics 2007-05-23 Witold Maciejewski

We present accurate simulations of the dynamical bar-mode instability in full General Relativity focussing on two aspects which have not been investigated in detail in the past. Namely, on the persistence of the bar deformation once the…

Astrophysics · Physics 2008-11-26 Luca Baiotti , Roberto De Pietri , Gian Mario Manca , Luciano Rezzolla

The Kelvin-Helmholtz instability serves as a simple, well-defined setup for assessing the accuracy of different numerical methods for solving the equations of hydrodynamics. We use it to extend our previous analysis of the convergence and…

Instrumentation and Methods for Astrophysics · Physics 2020-12-09 Martin Obergaulinger , Miguel-Ángel Aloy