Parametric study of liquid-vapor interface within a woven metallic wire mesh screen

Porous wicks are employed in two-phase thermal management devices such as heat pipes and vapor chambers. The capillary forces generated across the liquid-vapor interface in these wick structures causes circulation of working fluid. The liquid flow in such wicks are typically characterized by low Bond (Bo = ρgL
²
/σ), Capillary (Ca = μV/σ) and Reynolds (Re = ρνL/μ) numbers [Bo ~ O(10
^-7
), Ca ~ O(10
^-5
), and Re ~ O(10
^-2
)]. This paper attempts to focus on the flow characteristics of one such porous wick - a single layered micron diameter metallic wire mesh screen. This screen, folded to form an accordion, is employed in the evaporator package of a novel two-phase heat transfer device and functions similar to a thermal wick. A single repeat unit of this screen is investigated to obtain the shape of the liquid-vapor interface using a numerical model. The wires are assumed to be woven in a sinusoidal pattern. An interface-tracking scheme, the volume-of-fluid (VOF) technique, is utilized and the 3D finite-volume model is solved for the liquid-vapor meniscus. Water is employed as working fluid in this study. The paper reports variation of capillary pressure across this computationally obtained liquid-vapor interface under static equilibrium condition. In addition to the parametric study based on the amount of liquid fill in the screen, investigated by Meniscus height (H), the paper also investigates the impact of equilibrium contact angle (θ) on the interface of the screen.