Effects of V-shaped rib arrays on turbulent heat transfer and friction of fully developed flow in a square channel

Abstract

This study examines turbulent heat transfer and friction characteristics of fully developed flow of air in a square channel in which two opposite walls are roughened with aligned arrays of V-shaped ribs. The rib-roughened channel models the internal cooling passages in modern gas turbine airfoils. The anglesof-attack of the V-shaped rib arrays are 45°, 60°, 90° (same as 90° full ribs), 120°, and 135°. The 60° V-shaped ribs with p e = 10 have the highest ribbed wall heat transfer and smooth wall heat transfer for a given air flow rate, and the highest channel heat transfer per unit pumping power. They are recommended for internal turbine airfoil cooling, replacing 45° or 60° full ribs.