Applying Asymptotic Approximations to the Full Two-Fluid Plasma System to Study Reduced Fluid Models

Summary form only given. Simulations are performed using the full two-fluid plasma system. The two-fluid plasma model is investigated for its capabilities of capturing physics that is lost with simpler fluid models such as magnetohydrodynamics (MHD). The regime in between the full two-fluid equation system and MHD is explored by the application of asymptotic approximations to the two-fluid system. These asymptotic approximations involve ignoring electron inertia, setting the speed of light to infinity and ensuring charge neutrality. Applying all three approximations together gives Hall MHD. The results obtained by applying the asymptotic approximations are compared to the two-fluid plasma model to determine what physics is lost by the application of each approximation. Simulations of electromagnetic plasma shock and collisionless reconnection will be presented to demonstrate the various physical effects in comparison to the results of the two-fluid model.