The influence of combustor swirl on pressure losses and the propagation of coolant flows at the large scale turbine RIG (LSTR)

Abstract

The aerothermal interaction of the combustor exit flow on the subsequent vane row has been examined at the Large Scale Turbine Rig (LSTR) at Technische Universität Darmstadt. A baseline configuration with axial and swirling combustor inflow have been studied subsequently. The NGV featured endwall cooling, airfoil film cooling and a trailing edge slot ejection as well as NGV-rotor wheel space purge flow. CO2 is injected for coolant flow tracing and the results are compared to 5HP measurements. The hub side endwall coolant injection is detected to influence the pressure losses in the NGV. It also has an impact on the TE coolant ejection. For swirling combustor inflow, increased NGV pressure losses and increased mixing of RIDN and main flow is observed. An influence of the clocking position of swirler to vane is detected. Additional losses within the NGV stage can be assigned to the swirler by means of flow tracing.