Accession Number : ADA136896

Title :   Roughness Effects on Compressor Blade Performance in Cascade at High Reynolds Number.

Descriptive Note : Master's thesis,

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

Personal Author(s) : Tanis,F J , Jr

PDF Url : ADA136896

Report Date : Nov 1983

Pagination or Media Count : 112

Abstract : An experimental investigation of the effect of roughness on compressor blade performance in cascade at high Reynolds numbers was performed. A 7-blade cascade of NACA 64-A905 blades with a chord of 2 in. and aspect ratio of 1 was tested in linear cascade. The blades were mounted with a stagger angle of 31 deg and angle of attack of 15 deg. Spacing between blades was 1.33 in. which gave a solidity of 1.5. This study was divided into two parts: to determine the importance of the location of roughness on blade performance; and to determine how the degree of roughness affects blade performance. The velocity and turbulence intensity profiles of the flow region downstream of the center blade and the non-dimensional total pressure loss parameter omega bar were used to evaluate blade performance. Hot wire anemometry measured velocity and turbulence intensity profiles downstream of the blade. Measured exit velocity and static pressure were used to derive the exit total pressure. Roughness located near the leading edge of the blade caused the greatest impact on omega bar and the velocity and turbulence intensity profiles. Changes in magnitude of roughness did not affect blade performance until a threshold was exceeded; then performance decreased rapidly.

Descriptors :   *Cascades(Fluid dynamics), *Compressor blades, *Surface roughness, Reynolds number, Turbulence, Cascade structures, Angle of attack, Position(Location), Leading edges, Pressure, Losses, Threshold effects, Intensity, Coefficients, Surface finishing, Exits, Velocity, Static pressure, Hot wire anemometers, High rate, Theses

Subject Categories : Fluid Mechanics
      Jet and Gas Turbine Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE