CUED Publications database

On the acoustics of a turning mid turbine frame with embedded design in a two-stage test-turbine

Faustmann, C and Zerobin, S and Spataro, R and Marn, A and Heitmeir, F and Göttlich, E (2015) On the acoustics of a turning mid turbine frame with embedded design in a two-stage test-turbine. In: UNSPECIFIED.

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The paper deals with the investigation of the noise generation in the two-stage two-spool test turbine located at the Institute for Thermal Turbomachinery and Machine Dynamics (ITTM) at Graz University of Technology. The facility is a continuously operating cold-flow open-circuit plant which is driven by pressurized air. The flow path is formed by a transonic turbine stage (HP) followed by a low pressure turbine stage consisting of a turning mid turbine frame and a counter-rotating LP-rotor. Downstream of the low pressure turbine the measurement section is instrumented with acoustic sensors. The acquisition system consists of a fully circumferentially traversable microphone array located at the outer casing. Two configurations of turning mid turbine frames were tested. The baseline is an intermediate turbine duct with 16 turning struts. The second one is a new embedded concept for the turning mid turbine frame with two zero-lift splitters placed in the struts' passages. In total 48 vanes (16 struts plus 32 splitter vanes) guide the flow from the HP-rotor to the LP-rotor. In order to determine the noise emission of both configurations the microphones signal spectra and the emitted sound power level are compared. The acoustic field is characterized by azimuthal and radial modes by means of a microphone array traversed over 360 degrees. In the multi-splitter configuration, the overall sound power level depending on the blade passing frequency (BPF) of the HP turbine is reduced by 7 dB and depending on the BPF of the LP turbine by 4 dB, respectively. The overall effect is a reduction of the acoustic emission for the turning mid turbine frame with embedded design.

Item Type: Conference or Workshop Item (UNSPECIFIED)
Divisions: Div A > Turbomachinery
Depositing User: Cron Job
Date Deposited: 17 Jul 2017 20:07
Last Modified: 27 Jul 2017 05:35