CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT > Fluent Multiphase

Solution method

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 13, 2015, 11:35
Default Solution method
  #1
New Member
 
michela cagna
Join Date: Sep 2014
Posts: 2
Rep Power: 0
michimichi88 is on a distinguished road
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
File Type: jpg previewfitta.jpg (52.0 KB, 7 views)
File Type: png preview.png (22.6 KB, 2 views)
michimichi88 is offline   Reply With Quote

Reply

Tags
eulerian model, quick, solution method, tetrahedral mesh


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
spatial discretization VOF, solution method Ema40 Fluent Multiphase 0 December 18, 2014 03:37
Solution of problem through Matrx Block Method Naseem Ahmad Main CFD Forum 0 August 17, 2012 05:10
Solution Method & turbulent intensity in CFX 5.5.1 hamza albazzaz CFX 7 June 29, 2011 12:39
water hammer solution by finite volume method A.Maleki Main CFD Forum 1 January 20, 2010 20:46
About the difference between steady and unsteady problems Lisa Main CFD Forum 11 July 5, 2000 14:37


All times are GMT -4. The time now is 16:15.