The present article defines analytical dependencies of thermal-physical properties of gas environment (helium and argon), which are necessary to model the process of granules production by the rotating electrode with plasma heating (PREP) method. Numerical modelling of the process allows predicting parameters of the material structure before the experiment and also forecasting new mechanisms of interrelations between process modes and granule crystallization. The research results showed the interrelation of aerodynamic and thermal models, as at aerodynamic calculations it is necessary to consider the dependence of the Reynolds number on temperature. The revealed dependencies are of great applied value, as they ensure the considerable increase in the calculation accuracy when modeling aerodynamic and thermal processes of electrodes dispersion.