Additively manufactured hybridized heat sinks co-optimized for simultaneous thermal enhancement and weight reduction

Abstract

Topology optimization for thermal design application is a powerful mathematical tool to optimize material distribution and maximize performance. However, since the interfacial area between the two phases is not considered in the design algorithm, conventional topology optimization strategies often produce bulky structures, compromising thermal performance. In this work, we devise a new sequential additive-subtractive topology optimization approach to overcome the inability of conventional topology optimization methods to reduce structure size, thus, enabling the simultaneously thermal performance enhancement and weight reduction. Using natural convection air-cooled heat sinks as a demonstration framework, we first showed that the bulky structures developed by conventional topology optimization exhibited poorer cooling performance than traditional plate-fin structures with the same solid fraction, due to its low surface area-to-volume ratio. Thereafter, we developed a new class of hybridized heat sinks by the use of additive-subtractive topology optimization method. Our results show that the hybridized heat sinks exhibit as high as 23 % and 15.46 % decrease in thermal resistance as compared to conventional topology optimized and the best plate fin heat sink design respectively, while achieving weight reductions of 45 % and 15 %. In addition to demonstrating the potential of the hybridized heat sinks for weight-sensitive cooling applications, the optimization methodology developed in this work can also provide useful guidelines for design and optimization of other thermofluidic devices.