An Experimentally Validated Lattice Boltzmann Model to Study Capillary Wicking Dynamics in Micro-Engineered Structures

Two-phase evaporative cooling devices such as vacuum chambers and heat pipes play a crucial role in thermal management of electronic systems. The advantages of these devices include high effectiveness due to phase change, uniform temperature distribution, and passive pumping via capillary wicking. Despite these advantages, the best cooling performance achieved experimentally to date still lags theoretical predictions. It is believed, a major bottleneck is the lack of detailed understanding of capillary wicking and the flow dynamics at micro and nano scales. To that end, this study focuses on developing an experimentally validated Lattice Boltzmann model to investigate the microscopic flow and wicking dynamics in micro-engineered structures. The numerical simulation is based on the phase-field method, which is capable of handling multiphase flows with large density and viscosity ratios (e.g., a water-air system), whereas the experimental validation will take advantage of advanced microfabrication techniques and particle image velocimetry to track the wicking front and map out the 3D flow field. The results provide valuable insight into the underlying physics and thus provide guidelines for better cooling device designs.