Study on initial stage of capillary rise dynamics

A multiphase lattice Boltzmann method (LBM) was developed to investigate capillary rise dynamics in a capillary tube. The numerical results give quantitative agreement with experimental data when inertia, the dynamic contact angle, and the entrance effect were taken into account. The results show that the capillary rise can be divided into an initial stage where the capillary rise dynamics significantly deviate from the well-known Lucas–Washburn (L–W) law, H∼t1/2, and a second stage where, however, approaches the predictions of the L–W law. The effects of gravity, adhesion, surface tension, viscous drag, inertia, and the tube radius on the initial differences are analyzed in detail to identify the mechanisms for the differences.