Effect of tip clearance on the thermal and hydrodynamic performance of a shrouded pin fin array

The effect of introducing tip clearance to a liquid cooled array of shrouded pins fins is examined. Three arrays of height to diameter ratio ranging from 0.5 to 1.1 were evaluated 2 experimentally. The arrays were exposed to a uniform heat flux of 0.02 to 0.26 W/mm(2) and cooled with water through a nominal Reynolds number range of 200 to 10,000. Tip clearance of 0 to 25% of pin height was assessed. Mean heat transfer rates and adiabatic pressure drop across the array were determined and empirical correlations are proposed. The introduction of clearance was seen to increase overall heat transfer in some cases.