An Experimental Study of Endwall and Airfoil Surface Heat Transfer in a Large Scale Turbine Blade Cascade

Abstract

Local rates of heat transfer on the endwall, suction, and pressure surfaces of a large scale turbine blade cascade were measured for two inlet boundary layer thicknesses and for a Reynolds number typical of gas turbine engine operation. The accuracy and spatial resolution of the measurements were sufficient to reveal local variations of heat transfer associated with distinct flow regimes and with regions of strong three-dimensional flow. Pertinent results of surface flow visualization and pressure measurements are included. The dominant role of the passage vortex, which develops from the singular separation of the inlet boundary layer, in determining heat transfer at the endwall and at certain regions of the airfoil surface is illustrated. Heat transfer on the passage surfaces is discussed and measurements at airfoil midspan are compared with current finite difference prediction methods.

Leading Edge Film-Cooling Effects on Turbine Blade Heat Transfer

“…It has been used satisfactorily by Boyle and Giel (1992), Ameri and Amone (1994a, b), and Boyle and Ameri (1994) for heat transfer calculations on turbine blades without film cooling, and by Hall et al (1994), and Garg and Gaugler (1994) with film cooling. In fact, Ameri and Amone (1994b) compared the Baldwin-Lomax model and Coakley's q-co model against experimental data of Graziani et al (1980), and found that the algebraic model was able to produce many of the flow features better than the twoequation model. They further state that this conclusion is strengthened when one takes into account the relative economy of computations with the algebraic model.…”

Investigation of Hot Streak Migration and Film Cooling Effects on Heat Transfer in Rotor/Stator Interacting Flows. Report 1

“…A set of viscous three-dimensional numerical simulations of flow through the Langston low speed turbine cascade with a thin inlet boundary layer (0.41 cm), including heat transfer and transition, have been performed using the TOMCAT3 numerical procedure and the predicted performance and heat transfer quantities compared to experimental data [49,50]. The heat flux values at the endwall and airfoil surfaces were specified to be the same as in Ref.…”

“…61). A slightly smaller vortex, which may be associated with the suction side leg of the horseshoe vortex, rotates in the counterclockwise direction and is located more towards the mid-span region than the secondary flow vortex [50]. The smallest vortex, which is probably associated with the suction side corner vortex, also rotates in the counter-clockwise direction and is located closer to the hub endwall than the other two vortices.…”

Film cooling effectiveness distribution of cylindrical hole injections at different locations on a vane endwall

“…The vortices originate from the leading edge horseshoe vortex migrate and develop through the entire passage [4]. The early researches on endwall mainly focused on the flow field structures, aerodynamic and heat transfer characteristics when it was unnecessary to cool the endwall [5][6][7].…”