Topology optimization of heat sinks in half-open space: a study on design domain

Abstract

Efficient heat sinks are the key components of heat dissipation devices. Although topology optimization can theoretically design high-performance heat sinks, screening a design domain in an open space is still a challenge. This work studies the topology optimization of three-dimensional (3D) heat sinks for LED chips using the variable density method, without considering air convection to save computing resources. A theoretical analysis proposes that the design domain should be approximately a hemisphere. Topology optimization is performed in three shaped design domains, namely cylindrical, conical frustum, and inverted conical frustum. By 3D printing three topology-optimized heat sinks, their actual heat dissipation effects on LED chips are compared. The experiment and simulation results consistently show that the heat sink in the conical frustum design domain has the best heat dissipation effect. Equipped with such a heat sink, a 5-W LED chip is 5.1°C cooler than that with the traditional finned heat sink. Our results show that a well-selected design domain can effectively balance the heat conduction and heat exchange, eventually leading to a better heat sink.