Log in

Login to your account

Username *
Password *
Remember Me
: 9 + 13 =

GPPS Journal Papers

Noise characteristics of a reduced blade count rotor with improved stage efficiency

User Rating: 5 / 5

Star ActiveStar ActiveStar ActiveStar ActiveStar Active
 
Rainer Schädler 1, Dominic D. Hänni 1, Anestis I. Kalfas 2, Reza S. Abhari 1,  Gregor Schmid 3,  Ewald Lutum 4, Carsten Schneider 4  
 
1 Laboratory for Energy Conversion ETH Zurich, Department of Mechanical and Process Engineering, Sonneggstrasse 3, CH-8092 Zurich, Switzerland
2 Department of Mechanical Engineering, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
3 Siemens AG, Mellinghofer Str. 55, D-45473 Muelheim an der Ruhr, Germany
4 MTU Aero Engines AG, Dachauer Str. 665, D-80995 Munich, Germany

Abstract

A reduction in rotor blade count in combination with a gain in aerodynamic performance is a desirable design goal for gas turbines to reduce the overall operational costs. Reducing the number of blades provokes inherently an increase in blade loading which drives the secondary flow strength. In the presented experimental work, the results of inter-stage probe measurements in a highly loaded 1.5-stage axial turbine rig show the potential to improve the stage efficiency for a reduced blade count rotor with respect to a baseline configuration with more blades. Time-resolved probe measurements reveal the detrimental effects on the turbine tonal noise level. It is found that the periodic vorticity fluctuations induced by the interaction of the rotor passage secondary flow structures with the potential field of the downstream stator, leads at specific span positions to a strong increase in the noise level at rotor exit with respect to the baseline. Both, the downstream effect of the convected rotor flow structures as well as the periodic interaction of the second stator originated flow structures are found to drive the acoustic field of the turbine. Overall, the stage efficiency benefit achievement of 0.4% for a 22% reduction in rotor blade count is derogated by an increase in tonal noise by up to 13 dB at the second stator exit.

Read Full Paper (Visit Journal Website)

Global Power and Propulsion Society (GPPS)

Address

Address :

Landis + Gyr-Strasse 1, 6300 Zug, Switzerland

Tel. :

+41 44 632 50 72

Recent tweets

To minimize the potential impact of technical difficulties associated with a registration "bottleneck" occurring ju… https://t.co/z3cqVSd6nV
Vote today for your GPPS 2020 Awards candidate. Our new online form is now available. https://t.co/9axXsiXfwt
Register your place at the first GPPS Chania20 Online Conference. We look forward to hearing the latest leading-edg… https://t.co/gQLlKqkJ9E