Large-Eddy Simulations of Rayleigh-Taylor Instability in a Convergent Geometry

Large-eddy simulation (LES) is performed of a Rayleigh-Taylor mixing layer in a convergent geometry. The harmonic content of a multimode initial condition is varied, and effects of the initial condition on linear and non-linear growth rates are analyzed. Simulations are demonstrated to cover several bubble merger generations, and distance from self-similarity is quantified using the metric proposed by Morgan \emph{et al.} [Morgan, B.E., Olson, B.J., White, J.E., and McFarland, J.A., ``Self-similarity of a Rayleigh-Taylor mixing layer at low Atwood number with a multimode initial perturbation,'' \emph{J. Turbul.}, 2017]. Finally, turbulence profiles are compared against LES from a planar mixing layer and against one-dimensional Reynolds-averaged Navier-Stokes simulation.