Investigation of the tip-leakage losses in turbine axial stages

In turbomachinery, an influence of a tip-leakage flow on overall blade loss is crucial and its reduction is still worth striving for. In this paper a numerical analysis of the flow in tip seal of high-rotating gas turbine engine has been made. This analysis is a part of experimental research for testing the commercially used different tip seals solutions. Described test rig is predicted to be an universal tool for developing and examining different configurations of turbine blade tips. Presented numerical analysis is used to predict physical phenomena that may affect the rotor blade performance. In the numerical investigation the commercial Ansys CFX software was employed. The most important parameters were: mass flow rate at the inlet and outlet of the test bench, pressure and velocity distribution and the air temperature growth above the rotor. Also, an influence of test rig inlet and outlet geometry on flow uniformity was investigated. During the analysis the attention was focused also on minimizing the turbulence intensity in outlet area, that could cause significant difficulties in flow and stable work of the machine – generated eddies contributes to lower the mass flow rate.