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Forced convection heat transfer from pin fin arrays
Abstract
Extended surfaces in the form of fins are widely used to enhance heat dissipation from a surface. A review of the literature revealed that there exists considerable experience in experimental and numerical analyses for rectangular fins, but there is a scarcity of information on pin fins. This dissertation presents the findings of a comprehensive literature search on the state-of-the-art of pin fins, detailed experimental investigation of forced convection heat transfer from pin fin arrays involving complex flow fields that are caused by orientation of the fin arrays at various angles of inclination and fin tip clearances, and a simplified numerical analysis. An experimental investigation was conducted to study the forced convection/radiation heat transfer characteristics of three staggered and in-line pin fin arrays that had different fin diameter to interfin spacing ratios. The experiments were performed for two tip clearances, four to seven heat inputs to the array baseplate, two or three flow rates, two fin orientations and five different angles of inclinations with respect to the incoming flow field. Limited number of natural convection experiments were performed on one of the arrays. The combined mode rate of heat transfer was measured and the contribution of the radiation heat transfer was determined analytically. The flow field was studied through flow visualization, velocity and pressure measurements. The heat transfer results were used to establish an empirical correlation to evaluate and predict the performance of pin fin arrays subjected to complex boundary conditions. A simplified numerical analysis was performed for an in-line fin array with simple boundary conditions. The results showed that in general the overall rate of heat transfer (a) increased with an increase in Reynolds number; (b) increased as the angle of inclination was reduced from 90$\sp\circ$ to about 30$\sp\circ$ to 45$\sp\circ;$ (c) increased in the absence of clearance at the tip of the fins; and (d) decreased as the fin diameter to the interfin spacing ratio was increased from 0.333 to 0.667. It was observed that the forced convection rate of heat transfer was about 3 to 5 times higher than in natural convection.
Subject Area
Mechanical engineering
Recommended Citation
Maudgal, Vinod Kumar, "Forced convection heat transfer from pin fin arrays" (1992). Doctoral Dissertations Available from Proquest. AAI9305866.
https://scholarworks.umass.edu/dissertations/AAI9305866