Axial-slot casing treatments improve the efficiency of axial flow compressors: Aerodynamic effects of a rotor redesign

J. Anton Streit, Frank Heinichen, Hans Peter Kau

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

16 Scopus citations

Abstract

A state-of-the-art transonic compressor rotor has a distinct potential for increased efficiency if modified for improved interaction with an axial-slot type casing treatment. Reducing the number of blades and thus the surface lowers friction losses but increases tip clearance effects and deteriorates the stall margin due to the higher aerodynamic blade loading. The latter two negative effects can be compensated for by the casing treatment, thus restoring the required stall margin and gaining an overall reduction of losses. For the specific compressor rotor under investigation, the potential in polytropic efficiency is as high as 0.7%. The present study was performed using time-accurate CFD (URANS) simulations. Both the reference rotor as well as the modified design are analyzed regarding their interaction with the casing treatment. The traceability of the conclusions is assured by interpreting the detailed flow phenomena. The newly designed rotor is found to be favorably influenced by the casing treatment at design operating conditions whilst the reference only benefits at throttled operating points. Casing treatments are commonly used to broaden the operating range of existing compressors without changing the design of the compressor rotor itself. This study aims to show the possible transformation of this potential in the stall margin into efficiency at design operating conditions by implementing an appropriate rotor design.

Original languageEnglish
Title of host publicationASME Turbo Expo 2013
Subtitle of host publicationTurbine Technical Conference and Exposition, GT 2013
DOIs
StatePublished - 2013
EventASME Turbo Expo 2013: Turbine Technical Conference and Exposition, GT 2013 - San Antonio, Tx, United States
Duration: 3 Jun 20137 Jun 2013

Publication series

NameProceedings of the ASME Turbo Expo
Volume6 A

Conference

ConferenceASME Turbo Expo 2013: Turbine Technical Conference and Exposition, GT 2013
Country/TerritoryUnited States
CitySan Antonio, Tx
Period3/06/137/06/13

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