Pin-fin shape and orientation effects on wall heat transfer predictions of gas turbine blade

Abstract

Turbine blades are often exposed to the 'hot' gas environment and thus it is essential to apply effective cooling technique to extend the blade lifetime. In the present work, wall heat transfer characteristics inside a blade trailing-edge coolant passage were investigated by analyzing two baseline configurations experimentally studied by previous researchers. In addition, three new configurations were proposed by varying shape and orientation against an incoming airflow. All these five configurations adopted similar layout with five-row elliptic pin-fins in the main coolant region and one-row fillet circular pin-fin in the exit region. Validation study was started by two baseline configurations by comparing CFD predictions with experimental measurements, followed by wall heat transfer predictions of three newly proposed configurations. It was found that pin-fin shape and its orientation have considerable effects on the wall heat transfer characteristics, and that by rotating the pin-fin against incoming flow, some compromises could be achieved, such as higher heat transfer coefficient and lower pressure loss.