Session: 14-02 Rotating Cavities

Submission Number: 178399

Experimental Investigation of Heat Transfer on a Rotating Turbine Disk in a Rotor-Stator Cavity With Impingement Cooling 

In order to prevent damage to the highly loaded rotating turbine disks of gas turbines and to enable an efficient design of the secondary air system, precise knowledge of the corresponding component temperatures and heat transfer phenomena in rotor-stator cavities is crucial. Therefore, a new test rig was designed to investigate the surface temperatures on a rotating turbine disk in a rotor-stator and in a rotating cavity in detail. The design of the test bench is derived from an aero engine low pressure turbine configuration.

At the test bench, the design of the rotor creates a rotor-stator cavity in front of the instrumented disk and a rotating cavity at the back of the disk. The rotor is instrumented with a total of 30 thermocouples to measure the surface temperatures at different locations, which are recorded and transmitted via telemetry on the rotor. Air is injected frontally onto the disk through eight nozzles in a circumferentially symmetrical impingement jet configuration. The air can exit both the front rotor-stator cavity through a sealing gap between rotor and housing and exit the back rotating cavity through circumferential holes in the rotor. Furthermore, the piping system allows the introduction of thermal shocks in the injected air.

This paper presents first measurement results of the heat transfer on the turbine disk at this new test rig. First, test rig and methodology are described. The focus here is on the calculation of wall heat fluxes on the turbine disk using a numerical solid-state model in steady-state operating points. Subsequently, temperature profiles on the disk are compared for different circumferential Reynolds numbers, axial Reynolds numbers of the impingement jets and outlet mass flow ratios. These temperature profiles are used as boundary conditions in the numerical model to calculate corresponding heat fluxes and thus to describe the heat transfer phenomena for different operating conditions.

Presenting Author: Hendrik Kaltenborn Institute of Power Plant Technology, Steam and Gasturbines, RWTH Aachen University

Presenting Author Biography: 2013-2019: Bachelor's degree in mechanical engineering at the Technical University of Berlin
2019-2021: Master's degree in mechanical engineering at the Technical University of Berlin
Since 2021: Working at the Institute of Power Plant Technology, Steam and Gasturbines at RWTH Aachen University as a research assistant in the experimental group, with a focus on heat transfer phenomena in rotor-stator cavities

Authors:

Hendrik Kaltenborn Institute of Power Plant Technology, Steam and Gasturbines, RWTH Aachen University
Manfred Wirsum Institute of Power Plant Technology, Steam and Gas Turbines, RWTH Aachen University
Stephan Stotz MTU Aero Engines AG