Project is sponsored by the Austrian Research Agency FFG  

HELDECO CAD/CAM Fertigungstechnik GmbH

Project Coordinator: Institute for Thermal Turbomachinery and Machine Dynamics

Project Applicants / Contact: Dip.-Ing. Dr.techn. Andreas Marn (Project Manager), Dipl.-Ing. Florian Schönleitner

Abstract:

The demand of more silent and cleaner aero engines leads to new innovative engine concepts. In these concepts (e.g. open rotor) the rear engine bearing moves forward beneath the struts of the mid turbine frame. The struts of the turbine exit casing (TEC) need not to carry the engine mount any longer, hence the struts can be designed aerodynamically and acoustically optimised, which reduces the sound pressure level. The support function is now taken by the struts of the mid turbine frame, but these struts have to be thick and rigid, raising weight of the engine. Therefore, these concept removes the usually following vane row and integrates turning into the struts resulting in a turning mid turbine frame. Due to these changes the aerodynamically excitation of the adjacent low pressure turbine stages has changed and up to now numerical tools are not capable to reliable predict the fluid-structure-interaction. One important step towards these new engine architectures is to examine the influence of the changed components onto the forced response of the blading. Therefore, experimental investigations will be conducted at the Institute for Thermal Turbomachinery and Machine Dynamics using both, the low pressure turbine test rig and the two-spool rig. As first step, the influence of the TEC blading is investigated followed (second step) by the test concerning the turning mid turbine frame. In order to be able to separate the influence of the upstream blade rows from the overall influence (upstream and downstream blade rows) the first test is a strutless TEC. Then the influence of different TEC configurations is investigated. After that the effect of the turbine mid turbine frame struts is examined. As result the influence of the struts is examined and a data base is created which enables to calibrate numerical tool to improve the prediction quality.

Objective:

1. Improved understanding of the flow physics and excitation mechanisms of the low pressure turbine
2. Turbine exit casing (TEC)-Low Pressure Turbine (LPT) Interaction
3. Database for aeroelastic code calibration
4. Establishment of design rules and a validation database

Instrumentation:

First results:

1. Schönleitner, F., Traussnig, L., Heitmeir, F., Marn, A., 2015, " Modal Characteristics, Strain Gage Setup and 1-way FSI of a Low Pressure Turbine Rotor as Preparation for Upcoming Ex-perimental Aeroelastic Investigations," ASME Paper GT2015-42717.

2. Schönleitner, F., Traussnig, L, Marn, A., Heitmeir, F., 2015, "Detection of Mistuning due to Manufacturing Tolerances and Blading of a Low Pressure Turbine Rotor with Hammer Head Design of the Blade Root," 11th International Conference Vibrations in Rotating Machines.

3. Justl, M., Traussnig, L., Schönleitner, F., Marn, A., Heitmeir, F., 2014, "Numerical Investiga-tions Regarding Contact Modelling for Evaluating the Modal Characteristics of a Low Pressure Turbine Rotor Blading," ASME Turbo Expo, Düsseldorf, Germany.

Theses:

1. Traussnig, L., 2015, "Charakterisierung der modalen Eigenschaften einer Niederdruckturbinenbeschaufelung," Diploma Thesis
   


2. Justl, M., 2015, "Numerische Charakterisierung sowie aeroelastische Untersuchung einer Niederdruckturbinenbeschaufelung," Diploma Thesis