# Solution method

 Register Blogs Members List Search Today's Posts Mark Forums Read

May 13, 2015, 11:35
Solution method
#1
New Member

michela cagna
Join Date: Sep 2014
Posts: 2
Rep Power: 0
Hi!
I simulate a multiphase flow that have three phases (two are fluid, the third is granular (solid)). My mesh, imported from meshing, is tetrahedral. My simulation describes the Rayleigh- Plateau phenomenon that occurs between the two fluid phases (water and oil). In other words, my geometry is reported in the attach and consists in a chamber with a inlet capillary where flow water with beads. This chamber has a lateral inlet where flows oil phase. When the water(plus beads) leave the capillary, it fails in a jet and meets oil and, thanks to Rayleigh-Plateau law, this jets is fractionated in drops.
I simulate this problem using Eulerian model: first i used implicit method with second order upwind for momentum solution method and quick for volume fraction and with these methods simulations converged but I couldn't see the drops. Secondly i passed to explicit method with second order upwind for momentum solution method and geo-reconstructed for volume fraction, but my simulations diverged (for an higher courant number). So i reduced my time step till 1e-05 s but my simulations last too (127 days). I tried to change solution method for volume fraction: i passed from geo rec to compressive, but the situation is the same.
Is it possible that Fluent had a size limit? I explain my doubt: I simulate beads those have diameter from 50 to 400 um. My mesh has element size of 115um. Is possible that Fluent has a limit about size of granular phase and element size of the mesh.
The second question is: if i have a tetrahedral mesh, can i use QUICK solution method for volume fraction?

Thanks all!

Michela
Attached Images
 previewfitta.jpg (52.0 KB, 5 views) preview.png (22.6 KB, 2 views)

 Tags eulerian model, quick, solution method, tetrahedral mesh