Accession Number : ADA296726

Title :   The Effects of Low-Profile Vortex Generators on Flow in a Transonic Fan-Blade Cascade.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Gamerdinger, Peter M.

PDF Url : ADA296726

Report Date : MAR 1995

Pagination or Media Count : 113

Abstract : Two dimensional fully-mixed-out flow conditions were measured downstream of a two-passage transonic fan-blade cascade which had low-profile vortex generators (VGs) attached to the suction surfaces of the blades. The simulation was conducted using a blowdown wind tunnel at a Mach number of 1.4. The objective was to assess the effects of vortex generating devices on the suction surface shock-boundary layer interaction and the resulting losses. Measurements are reported from tests made with older aluminum blading, with and without VGs, and with a nominally similar new set of steel blading, with and without VGs. Differences between the old and new blading were found to be most significant. While shock structures appeared to be similar with VGs attached, dye injection showed that the shock-induced boundary layer separation was greatly suppressed and the downstream flow was much steadier. With VGs, the flow turning was improved by 0.94 degrees, but the flow loss coefficient increased by about 8%. An extension of the study is needed to fully assess the potential of using low-profile VGs in military fan engines. (AN)

Descriptors :   *SHOCK WAVES, *BOUNDARY LAYER, *TRANSONIC FLOW, *VORTEX GENERATORS, PRESSURE GRADIENTS, COMPUTERIZED SIMULATION, INJECTION, THESES, VORTICES, FAN BLADES, STEEL, PROFILES, ALUMINUM, WIND TUNNEL TESTS, DATA ACQUISITION, DYES, TWO DIMENSIONAL FLOW, SUCTION, FLOW SEPARATION, STATIC PRESSURE, PRESSURE DISTRIBUTION, GAS SURFACE INTERACTIONS, DOWNSTREAM FLOW, MOMENTUM TRANSFER, SPARK SHADOWGRAPH PHOTOGRAPHY, BLOWDOWN, CASCADES(FLUID DYNAMICS), FLOW VISULAIZATION.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE