Shape optimization of axial groove miniature heat pipes

Flat miniature heat pipes (FMHPs) are compact, passive thermal management devices that leverage phase change to sustain high heat fluxes. Their performance is strongly influenced by the geometry of the internal wick structure, which governs capillary-driven liquid transport. This work presents a reduced-order numerical model for predicting the steady-state thermal performance of FMHPs with axially grooved wicks. The model captures key thermohydraulic phenomena while enabling efficient gradient-based shape optimization by simplifying the governing equations and linearizing the phase-change mass flux. The groove width is parametrized along the axial direction and optimized to maximize the heat transport capacity. Validation against experimental and high-fidelity numerical results demonstrates the model’s accuracy and efficiency. Optimization results show that non-uniform groove profiles can significantly enhance performance, achieving up to 24% improvement in maximum heat input compared to uniform grooves, without increasing the device footprint. The study highlights the potential of shape optimization in advancing the design of high-performance FMHPs for electronics cooling and other heat-intensive applications. • Gradient-based shape optimization of grooved wicks in miniature heat pipes. • Reduced-order model enables fast and accurate thermal performance prediction. • Shape optimization improves heat input capacity by up to 24%. • Groove width variation enhances capillary flow and reduces pressure drop. • Model validated against experimental and high-fidelity numerical results.