vof simulation...magnetic fluid pressure fields.
 

Hi,
I am trying to model a flow of a magnetic liquid being manipulated by external; magnetic field.In fluent the effect of the magnetic force is implemented by a user defined source term.the problem is like ....initially i have a partially filled glass tube with one side connected to magnetic liquid container and other side open to atmosphere.the magnetic field will move the fluid against gravity and the fluid eventually will come out of the free end of the tube.

to track the fluid -air interphase I have used vof model in fluent.But there are couple of problems.
1.when I try to see the pressure in the fluid it shows onlyb the hydrostatic pressure variation which i dont want.obviously the magnetic force acts like a pump against gravity and develops some pressure head across the tube as it pumps the liquid up.so like every pump a pressure jump(static pressure rise) should be established across the tube.I cant see that in the plot.

2.what is implicit body force in vof gui?I am using externally defined body force.HOw this option can affect me?

3.Initially only a part of the tube is filled with liquid and rest is air.so the body force acts only on the liqiud since air is non magnetic.but eventually the entire tube is filled with the liquid and body force acts on the entire tube zone.How to implement this?in th udf,do i have to check each cell whether this has air phase or liquid phase and then apply the body force?

any help is greatly appreciated......