Effects of Local Thermal Nonequilibrium and Magnetic Fields on the Stability of Rotating Partially Ionized Plasma Heated From Below

Abstract

This study examines the impact of local thermal nonequilibrium (LTNE) on the stability of rotating partially ionized plasma (PIP) within a porous medium. The plasma, subjected to heating from below, is analyzed under various boundary conditions (BCs). Both nonlinear (via the energy method) and linear (using normal mode analysis) analyses are performed. Eigenvalue problems in both frameworks are formulated and solved using the Galerkin method, employing trigonometric or polynomial basis functions chosen to satisfy BCs, ensuring the robustness and reliability of the numerical results. The findings underscore the significant roles of medium permeability, compressibility, rotation, and magnetic fields on the stability characteristics of the system. The influence of collisional frequency among plasma components and the thermal diffusivity ratio on energy decay is also considered. The findings demonstrate that the Rayleigh-Darcy number is the same across both nonlinear and linear analyses, thereby negating the presence of a subcritical region and affirming global stability. Stabilizing effects of rotation, magnetic field influence, compressibility, and interphase heat transfer have direct relevance for optimizing plasma confinement in fusion reactors and understanding stability in astrophysical phenomena, such as accretion disks. Conversely, increased permeability and a higher porosity-modified conductivity ratio demonstrate destabilizing tendencies, hastening the onset of convection. Rigid-rigid bounding surfaces are identified as thermally more stable for confining the PIP. These findings underscore potential applications in advanced thermal management systems, plasma confinement technology, and other engineering designs requiring precise control over stability and heat transfer.