On the Numerical Study of Capillary-driven Flow in a 3-D Microchannel Model

In this article, we demonstrate a numerical 3-D chip, and studied the capillary dynamics inside the microchannel. We applied the level set method on the Navier-Stokes equation which incorporates the surface tension and two-phase flow characteristics. We analyzed the capillary dynamics near the junction of two microchannels. Such a highlighting point is important that it not only can provide the information of interface behavior when fluids are made into a head-on collision, but also emphasize the idea for the design of the chip. In addition, we study the pressure distribution of the fluids at the junction. It is shown that the model can produce nearly 2000 Pa pressure difference to help push the water through the microchannel against the air. The nonlinear interaction between capillary flows is recorded. Such a nonlinear phenomenon, to our knowledge, occurs due to the surface tension takes action with the wetted wall boundaries in the channel and the nonlinear governing equations for capillary flow.