Compressible Rayleigh-Taylor Instability with Local Heat Transfer and Large Transport Property Contrasts*

In extreme environments such as during Inertial Confinement Fusion (ICF) or supernovae explosions, the Rayleigh-Taylor (RT) instability may occur under large variations in density or fluid transport properties, either through temperature variation or differences in the fluid properties themselves.  We conduct DNS-quality simulations of the 3D fully compressible RT instability at various temperature ratios and transport property configurations, providing a more comprehensive overview of how heat conduction, large variations in transport properties and sudden changes in transport properties can affect the evolution of a RT mixing layer.  We consider the idealized configuration of a hotter, less dense fluid pushing against a colder, denser fluid.  Nonuniform fluid expansion/contraction induced by heat transfer can significantly affect local density differences and instability growth, causing profile asymmetries about the interface for flow and mixing statistics.  We observe departure from self-similar development of the mixing layer, along with misalignment between regions of mixing and regions of most intense turbulent activity, caused by both heat transfer and transport property contrasts.