A Large Scale Turbine Test Rig for the Investigation of High Pressure Turbine Aerodynamics and Heat Transfer With Variable Inflow Conditions

Abstract

Focusing on the experimental analysis of the effect of variable inlet flows on aerodynamics, efficiency and heat transfer of a modern high pressure turbine, the Large Scale Turbine Rig (LSTR) at Technische Universität Darmstadt has been extensively redesigned. The LSTR is a full annular, rotating low speed turbine test rig carrying a scaled 1.5-stage (NGV1 - Rotor - NGV2) axial high-pressure turbine geometry designed by Rolls-Royce Deutschland to match engine-realistic Reynolds numbers. To simulate real turbine inflow conditions, the LSTR is equipped with a combustor simulator module including exchangeable swirlers. Other inflow conditions include axial or turbulent inflow as well as altered relative positions of swirl cores and NGVs by traversing. To investigate combustor-turbine interaction, the LSTR offers a large variety of optical and physical access ports as well as high flexibility to the application of measurement techniques. An elaborate secondary air system enables the simulation of various cooling air flows. The turbine section is equipped with film-cooled NGVs, a hub side seal air injection between NGVs and rotor, as well as a hub side RIDN cooling air injection module designed to provide realistic turbine flow conditions. Exchangeable hub side RIDN-plates allow for investigation of different coolant injection geometries. Measurement capabilities include 5-hole-probes, Pitot and total temperature rakes, as well as static pressure taps distributed along NGV radial sections and at the hub side passage endwall. The NGV passage flow can be visualized by means of Particle Image Velocimetry (PIV). Hot Wire Anemometry (HWA) will be used for time-resolved measurements of the turbulence level at several positions. The distributions of heat transfer and film cooling effectiveness are acquired using infrared thermography and CO2-gas tracing.

The Influence of Combustor Swirl on Pressure Losses and the Propagation of Coolant Flows at the Large Scale Turbine Rig (LSTR): Experimental and Numerical Investigation

“…Flow tracing of the test rig's coolant flows is part of a comprehensive investigation of the aerothermal effects of combustor-turbine interaction at TU Darmstadt (Schmid et al [2,5], Krichbaum et al [17], Werschnik et al [18][19][20], Hilgert et al [21], Wilhelm et al [22]). The method is dedicated to improving the general understanding of the baseline flow field and to assess losses and flow features to coolant flows.…”

Experimental Investigation of Rotor Tip Film Cooling at an Axial Turbine with Swirling Inflow Using Pressure Sensitive Paint

“…Measurements were taken at the Large Scale Turbine Rig (LSTR) [6], which is a 1.5-stage, low speed test rig operating in closed-loop at cold, near-atmospheric conditions with engine-realistic nozzle guide vane (NGV) exit Reynolds numbers. The blades and vanes are based on an up-scaled high pressure turbine geometry (Designed by Rolls-Royce Deutschland, Dahlewitz, Germany).…”

Unsteady Phenomena at the Combustor-Turbine Interface

“…Schroll et al [17] developed techniques to measure accurately the velocity field exiting a combustor with reactive flow. The large scale turbine rig at the Technical University Darmstadt, described by Krichbaum et al [18], has been used for several detailed studies of combustor-turbine interactions effect on time-averaged quantities. Werchnik et al [19,20,21] traced cooling flows and measured Nusselt number and cooling effectiveness with different amounts of film cooling with axial and swirling inflow.…”