Advanced search
1 file | 244.38 KB Add to list

Kelvin-Helmholtz instabilities in smoothed particle hydrodynamics

(2011) EAS Publications Series. 48. p.405-406
Author
Organization
Abstract
We have investigated whether Smoothed Particle Hydrodynamics (SPH), equipped with artificial conductivity, is able to capture the physics of density/energy discontinuities in the case of the so-called shearing layers test, a test for examining Kelvin-Helmholtz (KH) instabilities. We can trace back each failure of SPH to show KH rolls to two causes: i) shock waves travelling in the simulation box and ii) particle clumping, or more generally, particle noise. The probable cause of shock waves is the Local Mixing Instability (LMI), previously identified in the literature. Particle noise on the other hand is a problem because it introduces a large error in the SPH momentum equation. We show that setting up initial conditions with a suitably smoothed density gradient dramatically improves results. Particle clumping is easy to overcome, the most straightforward method being the use of a suitable smoothing kernel with non-zero first central derivative. We present results to that effect using a new smoothing kernel: the LInear Quartic (LIQ) kernel. Furthermore, we present new Artificial Conductivity signal velocities that lead to less diffusion. The effects of the shock waves and of particle disorder become less important as the time-scale of the physical problem (for the shearing layers problem: lower density contrast and higher Mach numbers) decreases. At the resolution of current galaxy formation simulations mixing is probably not important. However, mixing could become crucial for next-generation simulations.

Downloads

  • (...).pdf
    • full text
    • |
    • UGent only
    • |
    • PDF
    • |
    • 244.38 KB

Citation

Please use this url to cite or link to this publication:

MLA
Valcke, Sander, Sven De Rijcke, and Elke Röediger. “Kelvin-Helmholtz Instabilities in Smoothed Particle Hydrodynamics.” EAS Publications Series. Ed. M Koleva, P Prugniel, & I Vauglin. Vol. 48. Les Ulis, France: EDP Sciences, 2011. 405–406. Print.
APA
Valcke, Sander, De Rijcke, S., & Röediger, E. (2011). Kelvin-Helmholtz instabilities in smoothed particle hydrodynamics. In M Koleva, P. Prugniel, & I. Vauglin (Eds.), EAS Publications Series (Vol. 48, pp. 405–406). Presented at the Conference on a Universe of Dwarf Galaxies (CRAL 2010), Les Ulis, France: EDP Sciences.
Chicago author-date
Valcke, Sander, Sven De Rijcke, and Elke Röediger. 2011. “Kelvin-Helmholtz Instabilities in Smoothed Particle Hydrodynamics.” In EAS Publications Series, ed. M Koleva, P Prugniel, and I Vauglin, 48:405–406. Les Ulis, France: EDP Sciences.
Chicago author-date (all authors)
Valcke, Sander, Sven De Rijcke, and Elke Röediger. 2011. “Kelvin-Helmholtz Instabilities in Smoothed Particle Hydrodynamics.” In EAS Publications Series, ed. M Koleva, P Prugniel, and I Vauglin, 48:405–406. Les Ulis, France: EDP Sciences.
Vancouver
1.
Valcke S, De Rijcke S, Röediger E. Kelvin-Helmholtz instabilities in smoothed particle hydrodynamics. In: Koleva M, Prugniel P, Vauglin I, editors. EAS Publications Series. Les Ulis, France: EDP Sciences; 2011. p. 405–6.
IEEE
[1]
S. Valcke, S. De Rijcke, and E. Röediger, “Kelvin-Helmholtz instabilities in smoothed particle hydrodynamics,” in EAS Publications Series, Lyon, France, 2011, vol. 48, pp. 405–406.
@inproceedings{2944790,
  abstract     = {We have investigated whether Smoothed Particle Hydrodynamics (SPH), equipped with artificial conductivity, is able to capture the physics of density/energy discontinuities in the case of the so-called shearing layers test, a test for examining Kelvin-Helmholtz (KH) instabilities. We can trace back each failure of SPH to show KH rolls to two causes: i) shock waves travelling in the simulation box and ii) particle clumping, or more generally, particle noise. The probable cause of shock waves is the Local Mixing Instability (LMI), previously identified in the literature. Particle noise on the other hand is a problem because it introduces a large error in the SPH momentum equation. We show that setting up initial conditions with a suitably smoothed density gradient dramatically improves results. Particle clumping is easy to overcome, the most straightforward method being the use of a suitable smoothing kernel with non-zero first central derivative. We present results to that effect using a new smoothing kernel: the LInear Quartic (LIQ) kernel. Furthermore, we present new Artificial Conductivity signal velocities that lead to less diffusion. The effects of the shock waves and of particle disorder become less important as the time-scale of the physical problem (for the shearing layers problem: lower density contrast and higher Mach numbers) decreases. At the resolution of current galaxy formation simulations mixing is probably not important. However, mixing could become crucial for next-generation simulations.},
  author       = {Valcke, Sander and De Rijcke, Sven and Röediger, Elke},
  booktitle    = {EAS Publications Series},
  editor       = {Koleva, M and Prugniel, P and Vauglin, I},
  isbn         = {9782759806621},
  issn         = {1633-4760},
  language     = {eng},
  location     = {Lyon, France},
  pages        = {405--406},
  publisher    = {EDP Sciences},
  title        = {Kelvin-Helmholtz instabilities in smoothed particle hydrodynamics},
  url          = {http://dx.doi.org/10.1051/eas/1148088},
  volume       = {48},
  year         = {2011},
}

Altmetric
View in Altmetric
Web of Science
Times cited: