The 6th International Conference on Matter and Radiation at Extremes (ICMRE2023)

42 / 2023-04-07 10:09:17

Linear Stability Analysis of the Radiation Effects on the Stratified Compressible Rayleigh-Taylor Instability

Radiation,Rayleigh-Taylor Instability,Compressible Flows

Radiation and Hydrodynamics > Hydrodynamic instability-poster

The influence of radiation on the Rayleigh-Taylor instability (RTI) developed from a stratified isothermal background state is studied by normal mode stability analysis. Radiation has a significant effect on the compressibility of the fluid, which alters the growth rate of the RTI. More specifically, increasing the radiative diffusion has a positive effect on the compressibility, which can increase the growth rate from the initial adiabatic limit to the isothermal limit. Meanwhile, increasing the radiative pressure has a negative effect on compressibility, causing the growth rate to approach the incompressible limit. The Peclet number, which characterizes the relative importance of convection and heat diffusion, and the Mihalas number, which characterizes the relative importance of internal and radiative energy, are found to be the key parameters determining the extent to which the growth rate can be affected. The radiation effects are studied at different Atwood numbers (At), stratification parameters (Sr) and diffuse thicknesses, showing that cases with low Atwood numbers, higher stratification parameters or larger diffuse thicknesses have more significant effects on the RTI growth rate.