A two-scale Langevin PDF model for Richtmyer-Meshkov turbulence with a small Atwood number

PHYSICA D-NONLINEAR PHENOMENA

卷:403

Article

Soulard, Olivier¹  Guillois, Florian¹  Griffond, Jerome¹  Sabelnikov, Vladimir²  Simoens, Serge³ 

[1] CEA, DAM, DIF, F-91297 Arpajon, France

[2] Off Natl Etud & Rech Aerosp, DMPE, Palaiseau, France

[3] Ecole Cent Lyon, MFAE LMFA, Ecully, France

关键词: Turbulence;    Probability density function (PDF);    Langevin model;    Richtmyer-Meshkov instability;    Permanence of large-eddies;    Pressure-velocity correlation;   

DOI  :  10.1016/j.physd.2019.132276

来源: Elsevier

【 摘 要 】

In this article, we derive a Langevin probability density function (PDF) model in order to predict turbulent mixing zone evolutions when generated by the Richtmyer-Meshkov instability. The aim of the model is to account for the permanence of large eddies which is observed in these flows when the density contrast, as measured by the Atwood number, is small. To this end, a two-scale decomposition of the velocity field is proposed and used to adapt existing Langevin models. In addition, the role played by pressure fluctuations on the transport of kinetic energy is also discussed. A closure for this turbulent process is added to the two-scale Langevin model. Finally, large-eddy simulations of Richtmyer-Meshkov turbulent flows are performed and used to validate the different closures proposed in this work. (C) 2019 Elsevier B.V. All rights reserved.

【 授权许可】

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