Effect of Pin Fin Arrangement on Endwall Heat Transfer

Abstract

Experiments were conducted to measure the local heat transfer on an endwall with pin fin array. Heat transfer behavior was examined for the cases of a single pin, a single row, in-line and staggered arrays having six streamwise rows. Thermosensitive liquid crystal film was used to measure the local heat transfer coefficient on the endwall. Neural network was applied for the color-to-temperature transformation of the thermosensitive liquid crystal. Local heat transfer on the endwall having a single row of pin fin was affected by flow acceleration between the pin fins rather than the horseshoe vortex around the pin fin. Therefore, the average Nusselt number exhibited a good correlation to the Reynolds number Re_nax, which was based on the average velocity of the minimum flow area, regardless of the pin fin spacing. For in-line and staggered arrays, the average Nusselt numbers correlated with the Reynolds number Re_maxdecreased with the reduction of the pin fin spacing.