Accession Number : ADA306384

Title :   Influence of a Moving Endwall on the Tip Clearance Vortex in an Axial Compressor Cascade.

Descriptive Note : Final rept.,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Personal Author(s) : Peter, Lawrence J.

PDF Url : ADA306384

Report Date : DEC 1995

Pagination or Media Count : 140

Abstract : This experiment involved the design, construction, validation and testing of a new facility for the investigation of vortices generated by compressor rotor blade tip clearance with a moving endwall. A five-tube pressure rake placed downstream of the trailing edge of a cascade of blades measured the pressure field for flow coefficients ranging from 20 to 1.66 and tip clearances of 0.33, 1.0, 1.7 and 2.4 percent chord. Contour plots of mass averaged pressure loss coefficient appear to show the no-flow tip vortex becomes entrained and diffused by the moving wall boundary layer. The high loss region near the moving wall contracts toward and extends toward the pressure side of the adjacent blade. This contraction results in a reduction in overall blockage in the passage with a corresponding reduction in passage losses, toward an apparent steady-state value, for increasing end wall speed and decreasing tip clearance.

Descriptors :   *VORTICES, *CASCADES(FLUID DYNAMICS), *AXIAL FLOW COMPRESSOR BLADES, PRESSURE GRADIENTS, MATHEMATICAL MODELS, OPTIMIZATION, PITCH(MOTION), THESES, BOUNDARY LAYER, COMPUTATIONAL FLUID DYNAMICS, FLOW VISUALIZATION, PRESSURE MEASUREMENT, MASS FLOW, FLOW FIELDS, TEMPERATURE GRADIENTS, WIND TUNNEL TESTS, DATA ACQUISITION, STATIC PRESSURE, PRESSURE DISTRIBUTION, STAGNATION PRESSURE, HEAT LOSS, AXIAL FLOW, TRAILING EDGES, THREE DIMENSIONAL FLOW, ANNULAR FLOW, AXIAL FLOW COMPRESSORS, BLADE TIPS.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE