Multiphase Folws

Dear all,

Hi. I’ m troubled with some unphysical phenomena.
I use multiphase programs,the first one is based on S-C model,the other one is Mean-field free-energy model…
Without external force and body force, the mass distribution of droplet is moving to the the middle of the droplet’mass is more with the time go on. and two programs have the same phenomena, only on S-Cmodel ,the change is more slowly.
I think the interfacial surface tension code may include the error.
But I have not gotten the solution.

Have anyone had the similar phenomena?
Please give me a advise.

Thank you.