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

Source term for diffusion equation in FLUENT 4.5

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 16, 2000, 17:01
Default Source term for diffusion equation in FLUENT 4.5
  #1
Raja Banerjee
Guest
 
Posts: n/a
Hi, I am trying to introduce source terms in the VOF model to simulate evapration. In addition to the source terms for VOF and pressure-correction equations, I want to have a source term for the diffusion equation in the region where the volume fraction of the liquid is between 0 and 1 i.e. at the liquid/gas interface to take into consideration the mass generation of the vapour at the interface. But I don't know how to target the source term for the vapour specie in the gas phase. There is a small note in the urstrm.f file about the same but I can't make out what does it mean. I would appreciate if somebody can help me. Thanks, Raja
  Reply With Quote

Old   August 31, 2000, 00:00
Default Re: Source term for diffusion equation in FLUENT 4
  #2
Greg Perkins
Guest
 
Posts: n/a
To introduce a source term for a species in a phase, add your term in urstrm.f under the area commented for SPECIES - EQ.

You then need to use IPHASE and NUMSPC to determine when your source term values (ATERM,BTERM) are required by Fluent.

Also, note that if you have a net amount of mass being transferred between phases, as you will have in evaporation - you will also need to activate the interphase mass transfer model and modify the usrmst.f subroutine. If you don't do this, no mass will be transferred between the phases and you won't have a mass balance. Also note that usrmst.f requires a volumetric mass rate (kg/m3-s) not a cell rate (kg/s) as other routines (that took a few more weeks to spot since its not documented!)

Good luck!

Greg Perkins

  Reply With Quote

Reply

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
momentum source term zwdi FLUENT 14 June 27, 2017 16:40
UDF for source term in momentum equation Enrico FLUENT 9 May 30, 2014 12:34
Source term in the mass balance equation Mehdi BEN HAJ Phoenics 0 January 31, 2007 17:30
How to add a source term in u or v equation? luckyluke Phoenics 3 December 13, 2004 03:52
How to deal with this energy equation source term? H.S.Fang FLUENT 2 December 27, 2001 07:42


All times are GMT -4. The time now is 17:49.