A methodology for centrifugal compressor stability prediction

The stable operation of centrifugal compressors is limited by well-known phenomena, rotating stall and surge. Although the manifestation of the full scale instabilities is similar to the ones observed in axial machines, the stall inception in centrifugal compressors is less well understood. This thesis focuses on developing an integrated methodology to predict the stability limit and the stall inception pattern in highly-loaded centrifugal compressors with vaned diffusers. The approach, based on a body force representation of the blade rows, is different from previous research in that the prediction is independent of compressor stability correlations and a-priori knowledge of the compressor characteristics. The methodology consists of a control volume analysis to define the body force fields based on steady, single-passage 3-D RANS simulations and a look-up table approach to capture the dependence of the body forces on the local flow parameters. The body force model was implemented in a finite volume scheme of an existing unsteady Euler solver for a full-wheel domain consisting of only 68,000 cells. The body force based compressor model was validated against high-fidelity 3-D RANS calculations and was applied to investigate the stall inception in a pre-production, 5.0 pressure ratio, high-speed centrifugal compressor stage of advanced design. The body force based simulation at 75% corrected design speed agreed with experimental measurements available at design speed in that the diffuser becomes unstable at operating points with a positively sloped diffuser static pressure rise characteristic.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Aeronautics and Astronautics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2009

Author dc:creator

• Benneke, Björn

Advisor dc:contributor.advisor

• Zoltán S. Spakovszky.

• Aeronautics and Astronautics.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/54609

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/54609