Accession Number : ADA312453

Title :   An Experimental Investigation of Heat Transfer, Transition and Separation on Turbine Blades at Low Reynolds Number and High Turbulence Intensity.

Descriptive Note : Final rept. 1 Nov 95-9 Jul 96,

Corporate Author : WRIGHT LAB WRIGHT-PATTERSON AFB OH

Personal Author(s) : Baughn, James W. ; Butler, Robert J. ; Byerley, Aaron R. ; Rivir, Richard B.

PDF Url : ADA312453

Report Date : 1995

Pagination or Media Count : 20

Abstract : The effects of turbulence intensity on the heat transfer distribution, transition and flow separation on a turbine blade was investigated at low Reynolds numbers. Measurements were performed in linear cascades (at both UCDavis and the USAF Academy) at low Reynolds number (67,000 to 144,000) representative of low pressure turbine stages at high altitude. Nominal turbulence intensities of 1% and 10% (generated with biplane lattice grids) were used. The heat transfer was measured with the uniform heat flux (UHF) or heated-coating method. The heated-coating was a gold-film and liquid crystals were used for the surface temperature measurement. A novel laser-tuft surface flow visualization method was also used. For low turbulence levels (1%) the pressure side of the blade exhibited streaks of varying heat transfer possibly associated with Taylor-Gortler vortices. With grid turbulence (10%) these streaks disappeared on the pressure side and the heat transfer nearly doubled. Gird turbulence also increased the heat transfer on the leading edge and suction surface, while advancing the location of boundary layer transition. Good agreement was generally found between the UCDavis and USAFA data. These cascade results compare favorably to those that have been reported with rotation.

Descriptors :   *HEAT TRANSFER, *TURBULENCE, *FLOW SEPARATION, PRESSURE GRADIENTS, STEADY STATE, LOW PRESSURE, VORTICES, FLOW VISUALIZATION, PRESSURE MEASUREMENT, TEMPERATURE GRADIENTS, THERMAL ANALYSIS, WIND TUNNEL TESTS, LEADING EDGES, BOUNDARY LAYER TRANSITION, HEAT FLUX, GAS TURBINE BLADES, FREE STREAM, SURFACE TEMPERATURE, PRESSURE DISTRIBUTION, REYNOLDS NUMBER, HOT WIRE ANEMOMETERS, STAGNATION POINT, CASCADES(FLUID DYNAMICS).

Subject Categories : Fluid Mechanics
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE