A Theoretical Determination of Convection Heat-Transfer Coefficients During Transition on the Suction Side of Turbine Airfoils.
AIR FORCE AERO PROPULSION LAB WRIGHT-PATTERSON AFB OH
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The relationships established by Dhawan and Narasimha for the friction coefficients between the laminar and turbulent boundary layers on flat plates is used to calculate the heat transfer coefficient distribution in the transition region of turbine blades with and without adverse pressure gradients. The computed values are compared with the experimental values obtained from airfoils tested in cascade rigs. In the tests, Reynolds numbers from 122,000 to 590,000 were used. Also, the results predicted by the Dhawan and Narasimha method are compared with those predicted by J. Pershs method. For the cases considered, the Dhawan and Narasimha method is found more accurate. It was concluded that the moderate levels of turbulence present in the boundary layer prior to transition do not influence the development of the transition process intiated by an adverse pressure gradient. Author
- Jet and Gas Turbine Engines