High rotation number effect on heat transfer in a trailing edge channel with tapered ribs

Detailed heat transfer measurements were conducted in a wedge-shaped channel with lateral flow ejection, which is commonly found in the trailing edge cooling cavities of the gas turbine blade. Tapered ribs were applied on the leading and trailing surfaces to enhance heat transfer. Rib spacing (P/e(max)) was 8 and the ratio of rib height to channel height (e/H) was 0.125. The inlet Reynolds number ranged from 10,000 to 40,000. At the highest rotational speed of 400 rpm, the inlet rotation number was 0.8. Effect of flow ejection on pressure drop, mass flow rate and heat transfer distribution were investigated. Results show that the configuration of this tapered rib enhances heat transfer on the ribbed surface but ejection still has pronounced effects on heat transfer distribution. The experimental data has been correlated with the high rotation number and high buoyancy parameter in ranges similar to industry applications. (C) 2011 Elsevier Inc. All rights reserved.