The Impact of Heat Release in Turbine Film Cooling

Abstract

The Ultra Compact Combustor is a design that integrates a turbine vane into the combustor flow path. Because of the high fuel-to-air ratio and short combustor flow path, a significant potential exists for unburned fuel to enter the turbine. Using contemporary turbine cooling vane designs, the injection of oxygen-rich turbine cooling air into a combustor flow containing unburned fuel could result in heat release in the turbine and a large decrease in cooling effectiveness. The current study explores the interaction of cooling flow from typical cooling holes with the exhaust of a fuel-rich well-stirred-reactor operating at high temperatures over a flat plate. Surface temperatures, heat flux, and heat transfer coefficients are calculated for a variety of reactor fuel-to-air ratios, cooling hole geometries, and blowing ratios. Results demonstrate that reactions in the turbine cooling film can result in increased heat transfer to the surface. The amount of this increase depends on hole geometry and blowing ratio and fuel content of the combustor flow. Failure to design for this effect could result in augmented heat transfer caused by the cooling scheme, and turbine life could be degraded substantially.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 2008
Accession Number
ADA482864

Entities

People

  • Dave S. Evans

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Advanced Electronics
  • Engineered Resilient Systems

DTIC Thesaurus Topics

  • Air Force
  • Boundary Layer
  • Chemistry
  • Combustion
  • Cooling
  • Dielectrics
  • Film Cooling
  • Gas Turbines
  • Geometry
  • Heat Flux
  • Heat Transfer
  • Heat Transfer Coefficients
  • High Temperature
  • Laser Induced Fluorescence
  • Materials
  • Surface Temperature
  • Turbines

Readers

  • Combustion and Flow Dynamics.
  • Internal Combustion Engine (ICE) Technology.