CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > COMSOL

Free surface Inlet-Outlet BC for a two-phase model - COMSOL MP (4.4)

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   November 22, 2014, 10:01
Default Free surface Inlet-Outlet BC for a two-phase model - COMSOL MP (4.4)
  #1
New Member
 
Amin Rahmat
Join Date: Jul 2014
Posts: 4
Rep Power: 11
aminrahmat is on a distinguished road
Dear all,

I am trying to simulate a laminar two phase flow passing over a cylinder with a phase-field model where the cylinder is submerged into the water (heavier fluid), as a part of my project. I have tried a couple of candidates for the boundary condition at the inlet and the outlet. Initially, I gave a uniform velocity at the inlet for both phases plus a zero pressure at the outlet, then I assigned a mass flow rate for both phases and mass flow rate at the exit and a few other failed attempts. Also I have tried to give a step function at the inlet for the volume fraction at the level of my free surface and give a uniform velocity which I could not even implement.

Receiving a piece of advice, I have recently tried to give a zero pressure gradient at both sides and a body force or a small acceleration in the x-direction (as my driving force), but it seems that after sometime (4% of run-time in my case) the "reciprocal of the step size" increases and causes a failure.

I would be glad if there is a solution for the problem.

Amin,
aminrahmat is offline   Reply With Quote

Reply

Tags
boundaries condition, comsol 4, free surface flow, two-phase flow

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
Cluster ID's not contiguous in compute-nodes domain. ??? Shogan FLUENT 1 May 28, 2014 15:03
Free surface is not falling (VOF MODEL, TANK DRAINAGE) Blue FLUENT 3 November 28, 2013 05:51
free surface outlet novice Siemens 2 October 19, 2005 07:31
About free surface model? Cheng, Y.C. Siemens 0 September 9, 2002 09:11
CFX4.3 -build analysis form Chie Min CFX 5 July 12, 2001 23:19


All times are GMT -4. The time now is 00:33.