NUMERICAL SIMULATION OF HEAT PIPE WITH VERIFICATION OF X-RAY CT
To cool small portable electronic devices that generate large amounts of heat, the heat pipe is required downsizing and its performance improvement. The efficiency depends on the capillary-driven flow of the working fluid in the micro-meter grooves of the pipe's wall. This fundamental flow phenomenon has not been clarified. For this purpose, a numerical simulation of fluid flow through micrometer-scale grooves was performed and verified through X-ray computed tomography. In simulations, the lattice Boltzmann method was used to model two-phase flow in the groove. By employing a suitable interface model, simulations of the fluid dynamics realized large density differences between vapor and liquid water. As a result, liquid water was observed to move up inside the vertically set rectangular groove. The liquid phase appears wedge-shaped and the liquid moves up from the bottom of the groove. Furthermore, a numerical simulation was performed for various grooves of different aspect ratios but constant area cross-section. The results indicated that a deeper groove supported larger liquid transport.