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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

An original spectral study of the compressible hybrid lattice Boltzmannmethod (HLBM) on standard lattice is proposed. In this framework, the mass andmomentum equations are addressed using the lattice Boltzmann method (LBM),while finite difference (FD) schemes solve an energy equation. Both systems arecoupled with each other thanks to an ideal gas equation of state. This workaims at answering some questions regarding the numerical stability of suchmodels, which strongly depends on the choice of numerical parameters. To thisextent, several one- and two-dimensional HLBM classes based on different energyvariables, formulation (primitive or conservative), collision terms andnumerical schemes are scrutinized. Once appropriate corrective termsintroduced, it is shown that all continuous HLBM classes recover theNavier-Stokes Fourier behavior in the linear approximation. However, strikingdifferences arise between HLBM classes when their discrete counterparts areanalysed. Multiple instability mechanisms arising at relatively high Machnumber are pointed out and two exhaustive stabilization strategies areintroduced: (1) decreasing the time step by changing the reference temperature$T_{ref}$ and (2) introducing a controllable numerical dissipation $\sigma$ viathe collision operator. A complete parametric study reveals that only HLBMclasses based on the primitive and conservative entropy equations are foundusable for compressible applications. Finally, an innovative study of themacroscopic modal composition of the entropy classes is conducted. Through thisstudy, two original phenomena, referred to as shear-to-entropy andentropy-to-shear transfers, are highlighted and confirmed on standardtwo-dimensional test cases.

A linear stability analysis of compressible hybrid lattice Boltzmann methods