Abstract— A filling process of the pressure bottle used for the air storage was investigated by numerical simulations. During the filling process, the temperature was rising up to maximal value and after that started to decline. The good match was found between experimental and numerical results. In order to reproduce the experimental conditions, the process of the filling bottle was controlled by the pressure which varied in time. This filling strategy influenced furthermore the mass flow rate and the air flow velocity. Because of the geometrical symmetry, the simulation was calculated as an axisymmetric problem.