Capillary Flow-Driven Heat Transfer Enhancement

Capillary flow in a microgroove for heat transfer enhancement is investigated. Competing effects of capillarity, shear, and available area for the liquid flow determine the critical (maximum) heat transport capacity. A model for fluid flow and heat transfer in the microgroove of a V-shaped cross section is developed, and an analytical solution of the governing equations is analyzed. The performances of the device (in particular, the onset of the dryout point and the propagation of the dryout length) depend on the groove angle, resulting in a nonmonotonic variation of the critical heat transport capacity. An optimal groove angle corresponds to the maximum critical heat transport capacity. This paper uncovers this capillary phenomenon for enhanced heat transfer and provides a potential solution for efficient thermal management at microscale; using the optimal angle knowledge, heat transfer in capillary flow-driven devices (e.g., star microheat pipes) could be significantly improved to meet current thermal management challenges