The spoiling effects of rim seal flow are studied at the Large Scale Turbine Rig (LSTR) at Technische Universität Darmstadt. Detailed flow field measurements and efficiency measurements were performed for various ingress and egress setups and will be presented in this paper. Efficiency measurements show an efficiency decrease as the rim seal mass flow is increased. Five hole probe measurements upstream and downstream of the second stator row show that an increasing rim seal mass flow leads to an increased pressure loss across the stator, to altered incidence angles and to an intensification of secondary flow structures within the lower 50% span. Static pressure taps at the stator profile primarily show altered aerodynamic loading with increased rim seal air. In addition, the end wall profile pressure was measured at the stator 2 hub. It can be seen that seal air injection causes increased pressure fluctuations on the platform. Temperature measurements with a temperature difference between rim seal and main annulus flow show that rim seal air primarily enters the passage vortex.

The influence of the sealing flows on the secondary flows of a low-pressure turbine has been assessed numerically using multi-row steady and unsteady simulations. The experimental data obtained at the Large Scale Turbine Rig (LSTR) at Technische Universität Darmstadt have been used to validate the numerical method and complement the simulations. Steady and unsteady state solutions and experiments are compared to understand the importance of the unsteadiness in the accuracy of numerical simulations. It is concluded that unsteady rotor/stator simulations enhance the prediction of the stator secondary flows, especially in the tip region. The effect of the sealing air is analysed, varying the cooling mass flow for two operating conditions. The penetration of the sealing flow in the main stream increases withthe cooling flow, displacing the horseshoe and passage vortices towards the mid-span.

The spoiling effects of rim seal flow are studied at the Large Scale Turbine Rig (LSTR) at Technische Universität Darmstadt. Detailed flow field measurements and efficiency measurements were performed for various ingress and egress setups and will be presented in this paper. Efficiency measurements show an efficiency decrease as the rim seal mass flow is increased. Five hole probe measurements upstream and downstream of the second stator row show that an increasing rim seal mass flow leads to an increased pressure loss across the stator, to altered incidence angles and to an intensification of secondary flow structures within the lower 50 % span. Static pressure taps at the stator profile primarily show alternated aerodynamic loading with increased rim seal air. In addition, the endwall profile pressure was measured at the stator 2 hub. It can be seen that seal air injection causes increased pressure fluctuations on the platform. Temperature measurements with a temperature difference between rim seal and main annulus flow show that rim seal air primarily enters the passage vortex.