Date of Award

12-1993

Document Type

Thesis

Degree Name

Master of Science in Aeronautical Engineering

Department

Department of Aeronautics and Astronautics

First Advisor

William C. Elrod, PhD

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°, +4.49°, +9.32° and +12.44°) 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° at the lowest incidence and by 3.7° 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.

AFIT Designator

AFIT-GAE-ENY-93D-9

DTIC Accession Number

ADA273744

Comments

The author's Vita page is omitted.

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