Experimental and Computational Investigation of Heat Transfer Effectiveness and Pressure Distribution of a Shrouded Blade Tip Section

An experimental and computational investigation was conducted to study the detailed distribution of heat transfer effectiveness and pressure on an attached tip-shroud of a turbine blade. Temperatures and pressures were measured on the airfoil-side and gap-side surfaces of the shrouded tip in a three-airfoil stationary cascade. The instrumented center airfoil and the two slave airfoils modeled the aerodynamic tip section of a blade and have the capability to vary tip clearance. The experiments were run at gaps varying of 0.25% to 1.67% of blade span and at an airfoil exit Reynolds number of 1.26×106 and Mach number of 0.95. The effect of coolant flow through the radial-cooled airfoil was also studied. The experimental results are compared with a computational model using the commercially available code, CFX. This unique study presents the influence of gap and coolant flow on the pressure distribution and heat transfer effectiveness of an attached tip-shroud surface.Copyright © 2004 by ASME