Saturation Of Rayleigh-Taylor Instability Research Articles

Impact of Boundary Roughness and MHD on Saturation of Rayleigh-Taylor Instability at the Interface between Two Superposed Couple-Stress Fluids

This study is about the influence at the boundary between two Couple-stress Casson fluids which are superposed on Rayleigh- Taylor instability (RTI) flowing in the existence of a uniform magnetic field acting normal to the surface in porous medium. The density of both the fluids is not the same. Established on fully developed approximations the stability analysis is applied, to achieve mathematical ease. The maximum wave numbers as well as resulting maximum frequency are found. In this analysis we discussed, the evolution of Rayleigh-Taylor unsteadiness due to non-Newtonian couple-stress Casson fluids over porous media. Graphical representations of stability that are discussed numerically based on the consequences of physical parameters for instance permeability parameter, non-Newtonian parameter, magnetic parameter, and couple-stress parameter.

Using Anisotropies as a Forensic Tool for Decoding Supernova Remnants

We present a method for analyzing supernova remnants (SNRs) by diagnosing the drivers responsible for structure at different angular scales. First, we perform a suite of hydrodynamic models of the Rayleigh–Taylor instability (RTI) as a supernova (SN) collides with its surrounding medium. Using these models we demonstrate how power spectral analysis can be used to attribute which scales in an SNR are driven by RTI and which must be caused by intrinsic asymmetries in the initial explosion. We predict the power spectrum of turbulence driven by RTI and identify a dominant angular mode that represents the largest scale that efficiently grows via RTI. We find that this dominant mode relates to the density scale height in the ejecta, and therefore reveals the density profile of the SN ejecta. If there is significant structure in an SNR on angular scales larger than this mode, then it is likely caused by anisotropies in the explosion. Structure on angular scales smaller than the dominant mode exhibits a steep scaling with wavenumber, possibly too steep to be consistent with a turbulent cascade, and therefore might be determined by the saturation of RTI at different length scales (although systematic 3D studies are needed to investigate this). We also demonstrate, consistent with previous studies, that this power spectrum is independent of the magnitude and length scales of perturbations in the surrounding medium and therefore this diagnostic is unaffected by “clumpiness” in the circumstellar medium.