[Omar_Elshawarby]

Hello,
I am working on a forward osmosis case study on COMSOL Multiphysics. As shown in the attached figure 1, the feed enters through the feed channel in which water (solvent) pass through the membrane to the Draw chamber while leaving the solute in the feed channel and so concentrating it before coming out.
My draw chamber is a tank which is continuously filled with the water (solvent) and so the water level will keep rising with time.
When trying to perform a time-dependent study on this system, the rising water level in the draw chamber will lead to expanding my computational domain with time and so more meshing elements should be added to the system.
One way to simulate this (which I am currently using now) is adding the physics of (Laminar Two-Phase Flow, Moving Mesh tpfmm) as shown in the attached figure 2. However, this physics is mainly used for two-phase flow to simulate interface moving and this is not my case.
Would you please help me to know which is the best way to simulate an expanding domain in COMSOL.