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Related papers: Modelling Shear Flows with SPH and Grid Based Meth…

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We investigate the Kelvin-Helmholtz instability occuring at the interface of a shear flow configuration in 2D compressible magnetohydrodynamics (MHD). The linear growth and the subsequent non-linear saturation of the instability are studied…

Astrophysics · Physics 2009-10-31 R. Keppens , G. Toth , R. H. J. Westermann , J. P. Goedbloed

We present an open-source Python library for simulating two-dimensional incompressible Kelvin-Helmholtz instabilities in stratified shear flows. The solver employs a fractional-step projection method with spectral Poisson solution via Fast…

Massive galaxies at high redshift are predicted to be fed from the cosmic web by narrow, dense, cold streams. These streams penetrate supersonically through the hot medium encompassed by a stable shock near the virial radius of the…

Astrophysics of Galaxies · Physics 2016-09-20 Nir Mandelker , Dan Padnos , Avishai Dekel , Yuval Birnboim , Andreas Burkert , Mark R. Krumholz , Elad Steinberg

We compare two state-of-the-art numerical codes to study the overall accuracy in modeling the intergalactic medium and reproducing Lyman-$\alpha$ forest observables for DESI and high-resolution data sets. The codes employ different…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-30 Solène Chabanier , J. D. Emberson , Zarija Lukić , Jesus Pulido , Salman Habib , Esteban Rangel , Jean Sexton , Nicholas Frontiere , Michael Buehlmann

We study liquid-vapor phase separation under shear via the Shan-Chen lattice Boltzmann model. Besides the rheological characteristics, we analyze the Kelvin-Helmholtz(K-H) instability resulting from the tangential velocity difference of the…

Soft Condensed Matter · Physics 2015-05-13 Ce Wang , Aiguo Xu , Guangcai Zhang , Yingjun Li

The study of shear layer instability in compressible flows is key to understanding phenomena from aerodynamics to astrophysical jets. Blumen's seminal paper [``Shear layer instability of an inviscid compressible fluid," J. Fluid Mech. {\bf…

Fluid Dynamics · Physics 2025-05-29 Symphony Chakraborty , Hsien Shang

In this paper, we study random dissipative weak solutions of the compressible Euler equations in the Kelvin-Helmholtz (KH) instability. Motivated by the fact that weak entropy solutions are not unique and can be viewed as inviscid limits of…

In this book chapter we describe the {\em Lagrangian} numerical relativity code \sphi. This code evolves spacetimes in full General Relativity by integrating the BSSN equations on structured meshes with a simple dynamical mesh refinement…

General Relativity and Quantum Cosmology · Physics 2024-05-22 S. Rosswog , P. Diener

We study the effects of Kelvin Helmholtz Instability (KHI) on the cold streams that feed massive halos at high redshift, generalizing our earlier results to include the effects of radiative cooling and heating from a UV background, using…

Astrophysics of Galaxies · Physics 2020-04-08 Nir Mandelker , Daisuke Nagai , Han Aung , Avishai Dekel , Yuval Birnboim , Frank van den Bosch

We investigate the perturbation dynamics in a supersonic shear layer using a combination of large-eddy simulations (LES) and linear-operator-based input-output analysis. The flow consists of two streams-a main stream (Mach 1.23) and a…

Fluid Dynamics · Physics 2024-07-26 Mitesh Thakor , Yiyang Sun , Datta V. Gaitonde

The Kelvin-Helmholtz (KH) instability of a shear layer with an initially-uniform magnetic field in the direction of flow is studied in the framework of 2D incompressible magnetohydrodynamics with finite resistivity and viscosity using…

Plasma Physics · Physics 2021-03-15 A. E. Fraser , P. W. Terry , E. G. Zweibel , M. J. Pueschel , J. M. Schroeder

Many dynamic pipe flow simulator tools are capable of predicting the onset of hydrodynamic flow instability through detailed simulation. These instabilities provide a natural mechanism for flow regime transition. The quality and reliability…

Fluid Dynamics · Physics 2018-11-29 Andreas Holm Akselsen

The weakly compressible Smoothed Particle Hydrodynamics (SPH) is known to suffer from the pressure oscillation, which would undermine the simulation stability and accuracy. To address this issue, we propose a generalized density dissipation…

Fluid Dynamics · Physics 2023-08-30 Bo Xue Zheng , Zhi Wen Cai , Pei Dong Zhao , Xiao Yang Xu , Tak Shing Chan , Peng Yu

We explore the effects of shear viscosity on the hydrodynamic evolution and final hadron spectra of Cu+Cu collisions at ultrarelativistic collision energies, using the newly developed (2+1)-dimensional viscous hydrodynamic code VISH2+1.…

Nuclear Theory · Physics 2010-04-06 Huichao Song , Ulrich W Heinz

In this paper we report on PD-SPH the new tree-sph code developed in Padua. The main features of the code are described and the results of a new and independent series of 1-D and 3-D tests are shown. The paper is mainly dedicated to the…

Astrophysics · Physics 2009-10-30 Giovanni Carraro , Cesario Lia , Cesare Chiosi

The interplay between shear and bulk viscosities on the flow harmonics, $v_n$'s, at RHIC is investigated using the newly developed relativistic 2+1 hydrodynamical code v-USPhydro that includes bulk and shear viscosity effects both in the…

Nuclear Theory · Physics 2014-09-17 J. Noronha-Hostler , J. Noronha , F. Grassi

Strong shear flow regions found in astrophysical jets are shown to be important dissipation regions, where the shear flow kinetic energy is converted into electric and magnetic field energy via shear instabilities. The emergence of these…

High Energy Astrophysical Phenomena · Physics 2014-04-03 E. P. Alves , T. Grismayer , R. A. Fonseca , L. O. Silva

Dust is present in a large variety of astrophysical fluids, from tori around supermassive black holes to molecular clouds, protoplanetary discs, and cometary outflows. In many such fluids, shearing flows are present, leading to the…

Astrophysics of Galaxies · Physics 2015-06-18 Tom Hendrix , Rony Keppens

A new variational inference method, SPH-ParVI, based on smoothed particle hydrodynamics (SPH), is proposed for sampling partially known densities (e.g. up to a constant) or sampling using gradients. SPH-ParVI simulates the flow of a fluid…

Artificial Intelligence · Computer Science 2024-07-29 Yongchao Huang

Using a new numerical code we have carried out two-dimensional simulations of the nonlinear evolution of unstable sheared magnetohydrodynamic flows. We considered two cases: a strong magnetic field (Alfven Mach number, M_a = 2.5) and a weak…

Astrophysics · Physics 2009-10-28 Adam Frank , T. W. Jones , Dongsu Ryu , Joseph B. Gaalaas