Are heuristic switches necessary to control dissipation in modern smoothed particle hydrodynamics ?

Fuente: arXiv
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Main Authors: García-Senz, Domingo, Cabezón, Rubén M.
Format: Preprint
Published: 2025
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author García-Senz, Domingo
Cabezón, Rubén M.
author_facet García-Senz, Domingo
Cabezón, Rubén M.
contents Artificial viscosity is commonly employed in smoothed particle hydrodynamics (SPH) to model dissipation in hydrodynamic simulations. However, its practical implementation today relies, in many cases, on complex numerical switches to restrict its application to regions where dissipation is physically warranted, such as shocks. These switches, while essential, are imperfect and can introduce additional numerical noise. In this work we develop and validate a more efficient shock capture scheme for SPH that does not rely on artificial viscosity switches. Recent studies have proposed that subtracting the linear component of the velocity field can suppress spurious dissipation in shear-dominated regions. Building on this idea, we implement a velocity-reconstruction technique that removes the bulk linear motion from the local velocity field and uses the Balsara correction to modulate the dissipation. The presented methodology yields a balanced dissipation scheme that performs well across a range of regimes, including subsonic instabilities, shear flows, and strong shocks. We demonstrate that this approach yields improved accuracy and lower spurious dissipation, compared to the reference viscosity switch used in this work.
format Preprint
id arxiv_https___arxiv_org_abs_2510_20534
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Are heuristic switches necessary to control dissipation in modern smoothed particle hydrodynamics ?
García-Senz, Domingo
Cabezón, Rubén M.
Fluid Dynamics
Instrumentation and Methods for Astrophysics
Artificial viscosity is commonly employed in smoothed particle hydrodynamics (SPH) to model dissipation in hydrodynamic simulations. However, its practical implementation today relies, in many cases, on complex numerical switches to restrict its application to regions where dissipation is physically warranted, such as shocks. These switches, while essential, are imperfect and can introduce additional numerical noise. In this work we develop and validate a more efficient shock capture scheme for SPH that does not rely on artificial viscosity switches. Recent studies have proposed that subtracting the linear component of the velocity field can suppress spurious dissipation in shear-dominated regions. Building on this idea, we implement a velocity-reconstruction technique that removes the bulk linear motion from the local velocity field and uses the Balsara correction to modulate the dissipation. The presented methodology yields a balanced dissipation scheme that performs well across a range of regimes, including subsonic instabilities, shear flows, and strong shocks. We demonstrate that this approach yields improved accuracy and lower spurious dissipation, compared to the reference viscosity switch used in this work.
title Are heuristic switches necessary to control dissipation in modern smoothed particle hydrodynamics ?
topic Fluid Dynamics
Instrumentation and Methods for Astrophysics
url https://arxiv.org/abs/2510.20534