The effort will build a modern simulation toolkit. We will develop a toolkit that uses modern numerical methods that capture the full geometry including the cathode chamber, constricted column, anode chamber, the nozzle, and the details of the geometry of the electrodes. We will also develop variable gas mixture equilibrium thermochemistry capability that enables flexibility of gas injection, e.g. Argon in the electrode regions and Air in the constricted arc region. We will implement modern turbulence models and couple 3D radiative transport models with realistic opacity tables for variable mixtures to MHD solver.