Experimental thermal field measurements of film cooling with twisted holes

Abstract

An experimental study has been conducted to study the heat transfer characteristics within corrugation film cooling holes of different cross section area square, rectangular and circular. The experiments investigation for this paper have been performed using a thermal IR camera, and the flow field has been analyzed by numerical calculation using a commercial code (FLUENT) was utilized and the SST k- ω turbulence model. The effect of blowing ratio (0.5, 1.0, 1.5 and 2.0) and twisted film cooling holes angles (90°, 180°, 270° and 360°) were also considered. A duct flow enters into a twisted film cooling hole in a cross direction. For the corrugation film cooling hole, it is observed that the reattachment of separated flow and the vortices within the hole enhance considerably the heat/mass transfer around the holes entrance region. Results showed that the twisted film cooling holes performed better than the cylindrical hole. Also, the film cooling effectiveness and heat transfer coefficient for the corrugation holes were strongly affected by the angle of twisted film cooling holes of the corrugation hole. Results show the heat transfer enhancement range of (1.5-2.7) time of smooth film cooling holes. Experimental and numerical calculation of film cooling effectiveness is validated with pervious experimental results