Affordable Collision-Radiative Model with Petrov-Galerkin Model Reduction for Thermochemical Non-Equilibrium Gas: An Expense Comparison and Showcase for Earth and Mars Atmospheres.

Thermochemical models and the detailed descriptions of the physics of nonequilibrium phenomena are computationally extremely expensive and are hence out of reach for early plasma researchers around the world. Throughout the years, researchers have modelled empirical formulations to meet the criteria of large-scale, multidimensional simulations. However, the resulting formulations have inherent assumptions that are often inaccurate and fail to capture the original physics. In addition to this, the need for rigorous research and maintenance of such deep formulations requires profound user supervision and a large number of parameter tunings, which broadens the gap for rising researchers to get firsthand complex phenomena-capturing frameworks. In this poster, the author addresses the state-specific thermochemical collision models (collision-radiative) through an efficient model reduction pipeline based on Petrov-Galerkin Projection of the nonlinear kinetic equations onto a low-dimensional subspace. This work is justified by the observation of kinetic systems, which tend to exhibit low-rank dynamics that rapidly move towards a low-dimensional subspace. The reduction is done for two complete atmospheres: Earth and Mars. The calculations of O₂ and N₂ rovibration are presented to show the efficiency of such projections into manageable state variables and the capturing of the complex phenomena in both macroscopic and microscopic quantities. The code can be implemented in a 16 GB RAM system.