Large eddy simulations of Rayleigh-Taylor turbulence

Xavier Silvani , Jacques Magnaudet (1)

1 IMFT - Institut de mécanique des fluides de Toulouse

This paper reports on Large Eddy Simulations (LES) of self-similar Rayleigh-Taylor (RT) turbulence in the incompressible limit. We first discuss the filtered governing equations and the associated subgrid-scale modelling. Having performed LES of RT turbulence for three different initial density ratios, we then provide results showing evidence of self-similarity. After a transition to fully developed turbulence (Re > 104), first order moments indicate a self-similar behavior of the mixing evolution. Furthermore, the internal structure of the turbulent flows presents a scale invariance, with velocity and concentration spectra following a Kolmogorov-Obukhov k-5/3 scaling. Several averaged properties characterizing the mixing evolution are computed. They are found to agree closely with available experimental and numerical data

Mots clés: Rayleigh-Taylor instability; Large Eddy Simulation; incompessible flow; variable density

Domaines: Thermique [physics.class-ph]

Xavier Silvani, Jacques Magnaudet. Large eddy simulations of Rayleigh-Taylor turbulence. 5th International Symposium on Turbulence, Heat and Mass Transfer, Sep 2006, Dubrovnik, Croatia. pp.117. ⟨hal-00189734⟩