Capillary enhancement effects and kinetic performances of internal helical protrusion micropores

Abstract

To enhance the capillary rise behavior in micropores, an internal helical protrusion micropore (MIHP) is proposed based on biomimetic ideas. The capillary dynamics models of the MIHP and the traditional smooth cylindrical micropore (MSC) were established and numerically simulated. The capillary rise behaviors in the pores were compared to reveal the mechanism of capillary enhancement. The result shows that: the internal helical protrusion structure reduces the effective diameter of the micropore, thus increasing the capillary rise effect. The pressure and velocity of the liquid in the MIHP are higher than those in the MSC. Within a cycle of the helical structure in the MIHP, the capillary behavior of the liquid is closely related to the shape of the helical structure. The lower edge of the protrusion suppresses the capillary rise of the liquid, while the upper edge of the protrusion promotes the capillary rise. The contact angle changes dynamically with the flow position of the liquid on the protrusion, which affects the wetting difficulty and leads to opposite effects of the upper and lower edges on the capillary rise. The structure optimization of the lower edge in the future will be an effective way to further improve the capillary effect.