Experimental Investigation of Innovative Internal Trailing Edge Cooling Configurations with Pentagonal Arrangement and Elliptic Pin Fin

[摘要] This paper describes a heat transfer experimental studyof four different internal trailing edge cooling configurationsbased on pin fin schemes. The aim of the study is thecomparison between innovative configurations and standardones. So, a circular pin fin configuration with an innovativepentagonal scheme is compared to a standard staggeredscheme, while two elliptic pin fin configurations are comparedto each other turning the ellipse from the streamwiseto the spanwise direction. For each configuration, heat transferand pressure loss measurements were made keeping theMach number fixed at 0.3 and varying the Reynolds numberfrom 9000 to 27000. In order to investigate the overall behaviorof both endwall and pedestals, heat transfer measurementsare performed using a combined transient technique.Over the endwall surface, the classic transient techniquewith thermochromic liquid crystals allows the measurementof a detailed heat transfer coefficient (HTC) map. Pin finsare made of high thermal conductivity material, and an inversedata reduction method based on a finite element codeallows to evaluate the mean HTC of each pin fin. Resultsshow that the pentagonal arrangement generates a nonuniformHTC distribution over the endwall surface, while, interms of average values, it is equivalent to the staggeredconfiguration. On the contrary, the HTC map of the twoelliptic configurations is similar, but the spanwise arrangementgenerates higher heat transfer coefficients and pressurelosses.

[学科分类] 力学，机械学