CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > FLOW-3D

How can I maintain a constant volume during the simulation period?

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 20, 2011, 08:45
Default How can I maintain a constant volume during the simulation period?
  #1
New Member
 
bejewel
Join Date: Jan 2011
Posts: 3
Rep Power: 15
bejewel is on a distinguished road
Boundary Conditions:
Xmin:wave
Xmax: outflow
front ,back & bottom:wall
top: outflow

How can I maintain a constant volume during the simulation period?
bejewel is offline   Reply With Quote

Old   January 20, 2011, 13:26
Default
  #2
Senior Member
 
michael barkhudarov
Join Date: Mar 2009
Location: Sante Fe, New Mexico, USA
Posts: 337
Rep Power: 18
MuxaB is on a distinguished road
Quote:
Originally Posted by bejewel View Post
Boundary Conditions:
Xmin:wave
Xmax: outflow
front ,back & bottom:wall
top: outflow

How can I maintain a constant volume during the simulation period?
Not easy. The degree of conservation depends on mesh resolution, VOF scheme used and velocity advection. Split Lagrangian VOF method may work better.
MuxaB is offline   Reply With Quote

Old   January 25, 2011, 12:40
Default
  #3
Senior Member
 
Jeff Burnham
Join Date: Apr 2010
Posts: 204
Rep Power: 17
JBurnham is on a distinguished road
To add to MuxaB's response, you can also make the domain long enough in the direction of wave propagation that the transit time required for three waves to reach the downstream outflow boundary is sufficient to find the results you need. The wave-propagation mass conservation issue at the outflow boundary usually takes three full wave fronts to start to significantly appear.
JBurnham is offline   Reply With Quote

Reply


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
mass flow in is not equal to mass flow out saii CFX 12 March 19, 2018 06:21
constant volume pump bc udf Adammada FLUENT 0 July 29, 2009 07:58
interDyMFoam - change in volume fraction gopala OpenFOAM Running, Solving & CFD 0 April 27, 2009 11:46
tidal flow simulation using finite volume method Jason Qiu Main CFD Forum 0 October 20, 2002 03:34
help needed about phase change Yanhu Guo Main CFD Forum 4 January 24, 2001 00:16


All times are GMT -4. The time now is 23:06.