Hi,

I am trying to model transient capillary driven of mineral oil displacing air between two parallel plates in FLUENT. The domain is two-dimensional with the length of the plates (axial span) being 200 times the channel spacing (transverse span). The two fluids are assumed immiscible. I used pressure inlet BCs (p=0) at both the entrance and exit. I am using the VOF model to calculate the volume fractions and the wall adhesion model to specify the contact angle, also I am specifying a surface tension. Naturally, this a low Re flow(Re~1). The problem is that the interface does not move from its original position. Can anyone shed some light into this.

Thank you in advance.

If I am understanding your problem correctly, the flow would have to be driven by the shape of the free surface. What initial free surface shape did you set? If you do not set up a free surface with some curvature, there may not be a sufficient pressure difference to initiate flow. Check the pressure distribution on your initial condition. The interface will not move without a pressure gradient. I hope that this helps.

Elliot

[nurfatinas]

I'm working on similar case study. How can I set the curvature on free surface? Do you mean to set some contact angle on wall adhesion in conjunction with the surface tension model?