Topology Optimization of Coral-Like Heat Sinks under Pool Boiling for Two-Phase Immersion Cooling
Abstract Heat sinks having extended surface area can substantially increase the heat dissipation limit of two-phase immersion cooling compared to the critical heat flux limit of flat surfaces. However, the highly nonlinear and boiling-regime-dependent surface boundary condition makes designing an optimal two-phase immersion heat sink a challenge, and no systematic design approach currently exists. In this work, we propose a density-based topology optimization method for designing heat sinks under pool boiling conditions. Boiling on a heat sink is modeled as a conduction problem with convective boundary condition, where the heat transfer coefficient is defined as a function of superheat and spans all boiling regimes (natural convection, nucleate boiling, transition boiling, and film boiling). The heat sink is represented as voxelized density distribution within the design domain, with the thermal conductivity modeled as a function of local density. The boiling boundary condi...