Investigation of transitional flows on compressor blades in cascade
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Authors
Holihan, Michael L.
Subjects
Advisors
Hobson, Garth V.
Date of Issue
2011-09
Date
Publisher
Monterey, CA; Naval Postgraduate School
Language
Abstract
Flow around polished second-generation controlled-diffusion blades in cascade set at their design inlet flow angle was investigated at various Reynolds numbers using static pressure measurements, five-hole probe surveys, twocomponent laser Doppler velocimetry (LDV), computational fluid dynamics and flow visualization. A suction-side separation bubble formed at Reynolds number, based on chord length, of 203,000 and collapsed by a Reynolds number of 393,000. Five-hole probe surveys characterized the blade-row inlet and outlet flow and showed the loss coefficient had a maximum value of 0.030 at a Reynolds number of 203,000 and a minimum of 0.012 at a Reynolds number of 400,000. The suction-side separation bubble was completely documented with LDV. The boundary layer was found to undergo laminar separation at 55 percent axial chord, transitioned in the boundary layer and re-attached turbulent by 67 percent axial chord. A quasi three-dimensional, Reynolds-Averaged Navier-Stokes, computational fluid dynamics model was created and accurately predicted the suction-side separation bubble and boundary layer transition inside the bubble. Flow visualization verified the transitional behavior of the separation bubble and showed the separation point was steady while the reattachment point was turbulent.
Type
Thesis
Description
Series/Report No
Department
Mechanical and Aerospace Engineering (MAE)
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funder
Format
xvi, 93 p. : col. ill. ;
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.