Operating peculiarities of the stage, the group of stages and the flow part of the steam turbine in low-flow modes, in particular, in the steamless and motor modes, and methodological approaches to their registration in the simulation of hydrodynamic processes are considered. Particular attention is paid to determining the power losses for friction and ventilation. The technique and algorithm for calculating the temperature state of the flow part of a steam turbine are given. Based on the conducted studies, the