Optimization of bionic heat sinks with self-organized structures inspired by termite nest morphologies

Abstract

Heat sinks were widely used solutions for thermal management. For over thirty years, the industry has been using regular pin-fins arrays or micro channels to construct heat sinks, which were insufficient to exploit the potential thermo-hydraulic performance of heat sinks. Recently, challenges that obstructed the evolution of heat sinks presented as a conjugated problem of topology description, flow-heat synergy, manufacturability constraints and multi-objective optimization. To tackle these difficulties, this study proposed a type of self-organization structures governed by termite nest morphologies for heat sink design. Taking advantage of the abundant geometric features produced by the self-organization equations, we converted the design area of a complex heat sink into a description of 18 parameters. Furthermore, we developed a non-gradient multi-objective method to optimize the topology parameters, pursuing for elevation of four performance objectives. The main novelties of the present study lay in the using of self-organized morphologies to define geometries, as well as the integration of the Gaussian surrogate model and the reference vector evolutionary algorithm for solving more than three-objectives heat transfer optimization problems. Three-dimensional conjugate heat transfer simulations were adopted for design evaluation. The results indicated that self-organized structures could fulfill heat dissipation requirements with smaller pressure drop, lower maximum temperature and more uniform temperature distribution as compared with pin-fin structures. Specifically, to achieve the same level of hot spot temperature, the selected self-organized structure decreased the pressure drop by 51%, reduced the temperature variance by 60% while only increased the solid volume by 3% compared with pin-fin structures.