Reducing kinetic energy losses by modifying the butt end of the gas turbine rotor blade

The paper proposes a variant of a gas turbine engine high pressure turbine rotor blade butt end design modification, aimed at reducing kinetic energy losses and increasing efficiency. The modification of the butt end design consists in its expansion due to the displacement of the wall section from the suction side to the flow area and elimination of the wall section in the trailing edge area of the airfoil. Thereby, a wide channel is formed in the end surface of the rotor blade, into which the gas enters, flowing over the radial clearance between the turbine rotor and stator. Numerical simulation was chosen as a research method. The computational model was verified and configured based on the results of previous tests. The results of numerical modeling showed that the proposed design of the rotor blade butt end allows reducing the kinetic energy losses in the rotor blade by more than 11% (rel.), increasing the efficiency of the high pressure turbine stage by more than 0,27% (abs.). The positive effect was achieved by changing the structure of secondary vortex structures, dividing large and intense vortex cores into small ones with lower intensity.