Accession Number : ADA332574

Title :   Experimental and Numerical Studies of Unsteady Heat Transfer in a Transonic Turbine

Descriptive Note : Final technical rept. 1 Jul 94-30 Jun 97

Corporate Author : VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Ng, Wing

PDF Url : ADA332574

Report Date : SEP 1997

Pagination or Media Count : 182

Abstract : The effects of a shock wave passing through a blade passage on surface heat transfer to turbine blades were measured experimentally. The experiments were performed in a transonic linear cascade which matched engine Reynolds number, Mach number, and shock strength. Unsteady heat flux measurements were made with Heat Flux Microsensors on both the pressure and suction surfaces of a single blade passage. Unsteady static pressure measurements were made using Kulite pressure transducers on the blade surface and end wails of the cascade. The experiments were conducted in a stationary linear cascade of blades with heated transonic air flow using a shock tube to introduce shock waves into the cascade. A time-resolved model based on conduction in the gas was found to accurately predict heat transfer due to shock heating measured during experimental tests without flow. The model under-predicted the experimental results with flow, however, by a factor of three. The heat transfer increase resulting from shock passing in heated flow averaged over 200 us (typical blade passing period) was found to be a maximum of 60% on the pressure surface near the leading edge. Based on experimental results at different flow temperatures, it was determined that shock heating has the primary effect on heat transfer, while heat transfer increase due to boundary layer disturbance is small.

Descriptors :   *HEAT TRANSFER, *GAS TURBINES, *TRANSONIC FLOW, SHOCK WAVES, AIR FLOW, BOUNDARY LAYER, COMPUTATIONAL FLUID DYNAMICS, PRESSURE MEASUREMENT, MACH NUMBER, UNSTEADY FLOW, HEAT FLUX, GAS TURBINE BLADES, STATIC PRESSURE, REYNOLDS NUMBER, SHOCK TUBES.

Subject Categories : Fluid Mechanics
      Thermodynamics
      Jet and Gas Turbine Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE