Virginia Tech
The Effect of Freestream Turbulence on Separation at Low Reynolds Numbers in a Compressor Cascade
Abstract
dc:description.abstractA parametric study was performed to observe and quantify the effect of varying turbulence intensities on separation and performance in a compressor cascade at low Reynolds numbers. Tests were performed at 25° and 37.5° stagger angle, negative and positive angles of incidence up until the point of full stall, Reynolds numbers from 6 x 104 to 12.5 x 104, and turbulence intensities from approximately 0.7% – 8%. Additionally, oil flow techniques were combined with static tap data to visualize the boundary layer characteristics at various test conditions. The overall performance of the cascade was presented and evaluated through mass-averaged total pressure loss coefficients. The results of the study showed that the best efficiency (lowest pressure loss coefficient) was determined by separation characteristics for any angle of attack. While adding turbulence generally delayed separation, in some cases, adding turbulence to a separated airfoil resulted in decreased performance. Very similar separation characteristics were observed for the full range of Reynolds numbers and stagger, with the higher stagger setting giving slightly better performance. It was shown that a large percentage of total pressure losses can be recovered by applying the appropriate turbulence intensity at any angle of attack, which is relevant to possibilities for active control of such flows.
Degree
thesis:*- Name thesis:degree_name
- Master of Science
- Level thesis:degree_level
- masters
- Discipline thesis:degree_discipline
- Mechanical Engineering
- Department dc:contributor.department
- Mechanical Engineering
- Grantor dc:publisher
- Virginia Tech
- Year dc:date.issued
- 2007
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Perry, Michael
- Chair dc:contributor.committeechair
-
- O'Brien, Walter F. Jr.
- Committee members dc:contributor.committeemember
-
- Paul, Mark R.
- Dancey, Clinton L.
- Wicks, Alfred L.
Subjects
dc:subject × 7Rights
dc:rights- Statement dc:rights
-
- In Copyright
- Licence dc:rights.uri
Identifiers
dc:identifier.*- Dc Identifier Other
- etd-11272007-004310
- OAI identifier oai:identifier
- oai:vtechworks.lib.vt.edu:10919/35834