Performance analysis and design optimization of heat pipe sink with a variable height fin array under natural convection

Abstract

To address the cooling problems in electronic equipment with high heat flux but small area under natural convection, a heat pipe sink with a novel fin array of unequal and continuously changing heights is proposed to improve heat transfer by reducing flow resistance. By means of three-dimensional numerical calculations, the comparison of heat transfer performance of heat pipe sinks with different variable-height fin arrays is performed. The results show that the fin arrays with larger height difference have lower flow resistance and higher local heat transfer coefficient. Parameter studies show that increasing the fin spacing (s) and the maximum fin height difference (p) can greatly reduce the material cost per unit power, Mtot, but their effects on the total thermal resistance, Rtot, are more complex. A multi-objective optimization analysis is further conducted based on the response surface method with consideration of minimum Rtot and minimum Mtot as objectives. Additionally, the optimization technique was integrated with the Non-dominated Sorting Genetic Algorithm II (NSGAII) and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) in order to improve the search speed and accuracy of Pareto solutions. By analyzing the Pareto solutions obtained, it is found that the influence of p and s on the system performance is related rather than independent.