Experimental and numerical investigation of trailing edge film cooling downstream of a slot with internal rib arrays

Abstract

To enhance turbine efficiency, the trailing edge thickness of stators and blades needs to be as thin as possible. One limitation on the trailing edge thickness is the requirement to cool this life-limiting region of the blade. One technique used to achieve a thin cooled trailing edge is that of a pressure side cutback with film cooling slots. There is a paucity of fluid and heat transfer data regarding this type of geometry which is currently being addressed by the EC-funded Framework V project AITEB. This paper reports on experimental work being undertaken by the University of Karlsruhe and accompanying computational fluid dynamics (CFD) calculations being performed by MTU Aero Engines and ALSTOM Power. Experimental and numerical data presented include cutback surface film cooling effectiveness together with slot discharge coefficient values.