Enhancing forced air convection heat transfer from an array of parallel plate fins using a heat pipe

Abstract

An experimental study of heat transfer from an array of copper plate fins supported by a copper heat pipe and cooled by forced air flow is presented. The results are compared to an identical array of copper fins, but supported by a solid copper rod. The primary variable is the height of the fin stack, while the fin pitch, air flow rate, surface area and fin shape are fixed. The results show that for some conditions fins of fixed pitch supported by a heat pipe dissipate higher heat transfer rates for the same surface temperature than fin arrays supported by a solid rod. The difference in heat transfer rates decreases as the height of the fin stack decreases. Maximum steady state heat fluxes and total powers were measured to be 80 W cm 2 and 800 W, respectively, for the tallest fin stack studied (10.16 cm) for an approach air velocity of 5.9 m s −1 and a surface temperature rise above the ambience of 160°. The fin stack supported by a solid copper rod dissipated 30 W cm 2 and 300 W for the same conditions. For the smallest height examined (2.54 cm) no significant advantage was realized by using a heat pipe to support the fin stack. A simplified analysis is also presented to predict surface temperature for a known heat input for both heat pipe supported and solid rod supported plate fin arrays. Predicted and measured values are in good agreement.