Author(s)

Kun Sun ¹

Affiliation(s)

¹ University of Shanghai for Science and Technology, Shanghai, China

Corresponding Author

Kun Sun

ABSTRACT

The capillary pressure and permeability of a wick jointly determine the liquid return capability and the heat transfer limit of heat pipes. In this work, a numerical model for spontaneous imbibition is developed by coupling phase transport in porous media, Darcy flow, and the Brooks-Corey relationships. Transient simulations are conducted for wicks with five particle sizes under two porosity conditions (ε), to evaluate the capillary performance and to propose a segmented particle-size enhancement strategy. The results show that, at ε = 26%, the wick performance increases monotonically with particle size. In contrast, at ε = 47%, the performance first increases and then decreases with particle size. A segmented design with particle sizes of 600 + 400 μm is therefore proposed, which improves the average mass flow rate and the average capillary rise velocity by 44.6% and 25.6%, respectively, compared with the best uniform particle-size case. The segmented configuration improves the early-stage liquid supply while maintaining a relatively high capillary head, thereby enhancing the overall capillary performance of the wick. These findings provide useful guidance for structural optimization and design of heat pipe wicks.

KEYWORDS

Heat Pipe, Sintered Copper Powder Wick, Capillary Pressure, Particle Size, Segmented Particle Size Structure

CITE THIS PAPER

Kun Sun. Numerical Simulation of Capillary Performance in Sintered Copper-Powder Wicks and Optimization of Segmented Structures. Journal of Engineering Mechanics and Machinery (2026). Vol. 11, No. 1, 40-51. DOI: http://dx.doi.org/10.23977/jemm.2026.110105.

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