Two-equation and multi-fluid turbulence models for Richtmyer-Meshkov mixing

Kokkinakis, Ioannis W. and Drikakis, Dimitris and Youngs, David L. (2020) Two-equation and multi-fluid turbulence models for Richtmyer-Meshkov mixing. Physics of Fluids, 32 (7). 074102. ISSN 1070-6631

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    Abstract

    This paper concerns an investigation of two different approaches in modeling the turbulent mixing induced by the Richtmyer–Meshkov instability (RMI): A two-equation K-L multi-component Reynolds-averaged Navier–Stokes model and a two-fluid model. We have improved the accuracy of the K-L model by implementing new modifications, including a realizability condition for the Reynolds stress tensor and a threshold in the production of the turbulence kinetic energy. We examine the models in the one-dimensional (1D) form in the (re)-shocked mixing of a double-planar air and sulfur-hexafluoride (SF6) interface of the Atwood number |At| ≃ 0.6853. Furthermore, we investigated the models’ accuracy to RMI-induced mixing of a (re)-shocked planar-inverse chevron air–SF6 interface. Relevant integral quantities in time, as well as instantaneous profiles and contour plots, are used to assess the models’ accuracy against high-resolution implicit large eddy simulations. The proposed modifications improve the efficiency of the K-L model. The model is designed as a simple model capable of capturing the self-similar growth of Rayleigh–Taylor and Richtmyer–Meshkov flows. The two-fluid model remains more accurate but is also computationally more expensive.

    ORCID iDs

    Kokkinakis, Ioannis W. ORCID logoORCID: https://orcid.org/0000-0001-9694-3764, Drikakis, Dimitris and Youngs, David L.;
    • Item type:Article
      ID code:73219
      Dates:
      Date
      Event
      2 July 2020
      Published
      15 June 2020
      Accepted
      Keywords:Richtmyer–Meshkov instability (RMI), Reynolds stress tensor, Reynolds-Averaged Navier– Stokes (RANS) model, two-fluid model, Physics, Physics and Astronomy(all)
      Subjects:Science > Physics
      Department:Faculty of Engineering > Mechanical and Aerospace Engineering
      Depositing user: Pure Administrator
      Date deposited:15 Jul 2020 13:49
      Last modified:03 Mar 2021 01:56
      URI:https://strathprints.strath.ac.uk/id/eprint/73219
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