English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Given the importance of shear flows for astrophysical gas dynamics, we study the evolution of the Kelvin–Helmholtz instability (KHI) analytically and numerically. We derive the dispersion relation for the two‐dimensional KHI including viscous dissipation. The resulting expression for the growth rate is then used to estimate the intrinsic viscosity of four numerical schemes depending on code‐specific as well as on physical parameters. Our set of numerical schemes includes the Tree‐SPH code  vine , an alternative smoothed particle hydrodynamics (SPH) formulation developed by Price and the finite‐volume grid codes  flash  and  pluto . In the first part, we explicitly demonstrate the effect of dissipation‐inhibiting mechanisms such as the Balsara viscosity on the evolution of the KHI. With  vine , increasing density contrasts lead to a continuously increasing suppression of the KHI (with complete suppression from a contrast of 6:1 or higher). The alternative SPH formulation including an artificial thermal conductivity reproduces the analytically expected growth rates up to a density contrast of 10:1. The second part addresses the shear flow evolution with  flash  and  pluto . Both codes result in a consistent non‐viscous evolution (in the equal as well as in the different density case) in agreement with the analytical prediction. The viscous evolution studied with  flash  shows minor deviations from the analytical prediction.

Modelling shear flows with smoothed particle hydrodynamics and grid‐based methods