A numerical study of axial turbine used to determine the level and characteristics of unsteady aerodynamic forces on the rotor blades. Numerical calculations based on the using of the package ANSYS CFX, which made it possible to obtain time-dependent change in the flow parameters and the aerodynamic forces on the rotor blades with variation rotor-stator axial spacing. The axial spacing area which corresponds to the minimum aerodynamic excitation was carried out.