Meniscus forces of liquid bridge between two parallel planes (comparison between exact solution and approximations)

This paper theoretically investigates the profiles of liquid bridge formed between two parallel planes and the meniscus forces acting on them, and shows the effects of the aspect ratio θof the bridge section and the contact angle on the meniscus force. Laplace pressure, which is a major contribution to the meniscus force, is calculated with the surface curvature of the meniscus profiles obtained by using the Delaunary surface. Surface tension on the triple line of the meniscus bridge, which is another contribution to the meniscus force, is also considered in the theoretical model. The theoretical results show that the latter contribution cannot be neglected for a region of θ > 0.1. By using the assumption of a circle curvature for the cross-section of the meniscus profile, the approximate solutions results are also calculated. These results demonstrate that the assumption is available for a wide range of θ when the meniscus forces are calculated with the surface curvature derived from both the radius of the meniscus bridge and the meniscus radius of the approximation circular arc and the effect of the surface tension on the triple line included. © 2012 The Japan Society of Mechanical Engineers.