New Experimental Setup for Assessing Turbine Vane Frame Aerodynamic Performance

Merli, F. (Speaker), Andreas Peters (Contributor), Patrick Zeno Sterzinger (Contributor), Wiesinger, L. (Contributor), Heitmeir, F. (Contributor), Göttlich, E. (Contributor)

Activity: Talk or presentationPoster presentationScience to science

Description

The Turbine Vane Frame (TVF) is a turning concept for intermediate turbine ducts, combining the functions of conventional Turbine Center Frames (TCFs) and the vane of the first stage of the Low Pressure Turbine (LPT). The TVF component plays a key role in turbine performance of a turbofan engine architecture, as the TVF has to guide the flow smoothly and separation-free over the radial offset between the High- and Low-Pressure Turbine (HPT, LPT). This poster shows why this solution can find successful application in new generation turbofan engines, particularly in geared turbofan architectures, which allow to decouple the fan and the LPT rotational speeds, leading to faster and smaller LPT stages, counter-rotating with respect to the HPT. In fact, compared to non-turning ducts, the TVF concept implies the removal of the first LPT vane row, due to the integration of advanced aerodynamic turning struts. Its employment is consequently expected to reduce the engine length, weight, cost and (indirectly) fuel burn.
The poster introduces an ongoing research program in the two-spool transonic test turbine facility, situated at the Institute of Thermal Turbomachinery and Machine Dynamics (ITTM) of Graz University of Technology. This project will advance the knowledge of the aerodynamic phenomena occurring in a TVF, therefore its results will be highly relevant for aero-engines manufacturers, in the challenging frame of a continuously growing air transport segment, combined with stricter international policies regarding pollutants emission.
The project consists of two experimental campaigns - (1) a baseline TVF configuration and (2) an optimized HPT-TVF-LPT design. The two-stage, two-spool test rig, capable of providing HPT and LPT purge flows, ensures engine-relevant operating conditions at the TVF inlet and outlet, an essential requirement to correctly address the HPT-TVF-LPT interaction mechanisms and evaluate the TVF performance. Since the aerodynamics of any intermediate duct is influenced by the level of incoming flow effects, variations of HPT tip clearance and purge flows are also planned, in order to assess their impact on TVF losses.
This poster presents the test setup and rig design, and the instrumentation and the measurements strategies. High-level results of pre-test numerical simulations of the HPT-TVF-LPT setup will also be shown to highlight important flow features and loss mechanisms which will be studied in detail and validated once the measurement data is obtained.
Period18 Jun 2019
Held atASME Turbo Expo 2018
Event typeConference
LocationPhoenix, United States, Arizona
Degree of RecognitionInternational