Off-Design Performance of Crenulated Blades in a Linear Compressor Cascade
Abstract
The effects of using compressor blades with a crenulated (notched) trailing edge in a low aspect ratio (AR= 1) linear compressor cascade at four incidence angles(-1.08 deg, +4.49 deg, +9.32 deg and +12.44 deg) were investigated. Blade performance and wake mixing characteristics for crenulated blades were compared with similar data for blades with a straight trailing edge. A seven-bladed cascade was operated with a flow Mach number of 0.4 and a blade chord Reynolds number of 4.1 (10)5. The diffusion factor ranged from 0.22 to 0. 42 and strong three-dimensional flow effects were present. Total pressure losses were measured with a total pressure rake. Velocities and flow angles were measured using hot-film anemometry. Crenulated blades were found to enhance wake mixing from 20 to 50 percent depending on blade loading and downstream location. Crenulated blades were also found to reduce flow deflection by 1.9 deg at the lowest incidence and by 3.7 deg at the highest incidence. At the highest blade loading, crenulations were found to reduce total pressure losses by 20 percent and inhibit large scale flow degradation and vortex breakdown. At mild blade loadings, negligible differences in losses were observed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1993
- Accession Number
- ADA273744
Entities
People
- Michael J. Costello
Organizations
- Air Force Institute of Technology