Session: 36-01 Transition Ducts and Flow Interactions II

Paper Number: 101915

101915 - On the Effect of Purge Air on the Aerodynamic Performance of a State-of-the-Art Turbine-Rear-Frame Guide Vane 

It is well known that the total pressure ratio and the turbine inlet temperature need to be increased to raise the thermal efficiency of a turbine stage. Therefore, a high exit gas temperature of the combustion chamber is essential to increase the thermal efficiency of aero engines. Consequently, the fluid temperature at the inlet of the Turbine Rear Frame (TRF) rises, too. Without any countermeasures, too hot fluid can enter the cavities between stationary and rotating parts through axial gaps causing damage to structural parts. To prevent such intrusion of hot fluid, cold purge air is blown out of the cavities and hence interacts with the main flow of the low-pressure turbine.
The present paper investigates the effect of purge air on the aerodynamic performance of a state-of-the-art Turbine Rear Frame Guide-Vane design. For this purpose, five-hole-probe data for three different purge-air flow rates are compared at the inlet and the exit plane of a scaled annular TRF Guide Vane cascade. Moreover, pressure tap data yields static pressure distribution information on the end wall. The influence of various angles of attack is discussed for nominal purge condition. The Investigation has been conducted at the Institute of Thermal Turbomachinery and Machine Dynamics of the Graz University of Technology.

Presenting Author: Malte Schien Graz University of Technology

Presenting Author Biography: Malte Schien finalized his studies in mechanical engineering in the year 2021. Subsequently, he began his doctoral program at the Institute of Thermal Turbomachinery and Machine Dynamics at Graz University of Technology. Until now, his studies focused on the aerodynamics of Low Pressure Turbines and Inter Turbine Ducts.

Authors:

Malte Schien Graz University of Technology
Christian Wakelam GE Aviation
Mattia Graiff Graz University of Technology
Emil Göttlich Graz University of Technology
Andreas Marn Graz University of Technology