CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Running, Solving & CFD

Different diffusivities

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

Reply
 
LinkBack Thread Tools Display Modes
Old   September 29, 2005, 14:29
Default Is it possible to set differen
  #1
Senior Member
 
Alberto Passalacqua
Join Date: Mar 2009
Location: Ames, Iowa, United States
Posts: 1,894
Rep Power: 26
alberto will become famous soon enoughalberto will become famous soon enough
Is it possible to set different diffusivities per each direction? I have to solve a scalar transport equation with a non-zero diffusion term in the X direction only.

Thanks in advance,
Alberto
__________________
Alberto Passalacqua

GeekoCFD - A free distribution based on openSUSE 64 bit with CFD tools, including OpenFOAM. Available as live DVD/USB, hard drive image and virtual image.
OpenQBMM - An open-source implementation of quadrature-based moment methods
alberto is offline   Reply With Quote

Old   September 29, 2005, 15:46
Default That would be called tensorial
  #2
Senior Member
 
Hrvoje Jasak
Join Date: Mar 2009
Location: London, England
Posts: 1,758
Rep Power: 21
hjasak will become famous soon enough
That would be called tensorial diffucivity (viscosity), right - have a search. You will need to define the diffusivity (field) as a tensor.

Enjoy,

Hrv
__________________
Hrvoje Jasak
Providing commercial FOAM/OpenFOAM and CFD Consulting: http://wikki.co.uk
hjasak is offline   Reply With Quote

Old   February 27, 2006, 18:56
Default Hi, I am solving for a pas
  #3
Member
 
Ankur Gupta
Join Date: Mar 2009
Posts: 38
Rep Power: 8
ankgupta8um is on a distinguished road
Hi,

I am solving for a passive scalar in the channelOodles case set-up. I would like to set the diffusivity of the passive scalar as some function of the passive scalar i.e. diffusivity will vary through out my computational domain. How can I specify that sort of diffusivity ?? It seems that this must be pretty straight forward but I am not able to figure out how??
Any help would be highly appreciated.

Thanks,
Ankur
ankgupta8um is offline   Reply With Quote

Old   February 27, 2006, 19:15
Default Yes. Specify the viscosity as
  #4
Senior Member
 
Hrvoje Jasak
Join Date: Mar 2009
Location: London, England
Posts: 1,758
Rep Power: 21
hjasak will become famous soon enough
Yes. Specify the viscosity as a volScalarField, set it to what you want and... that's it!

Enjoy,

Hrv
__________________
Hrvoje Jasak
Providing commercial FOAM/OpenFOAM and CFD Consulting: http://wikki.co.uk
hjasak is offline   Reply With Quote

Old   February 28, 2006, 02:47
Default Thanks Hrv..I was thinking on
  #5
Member
 
Ankur Gupta
Join Date: Mar 2009
Posts: 38
Rep Power: 8
ankgupta8um is on a distinguished road
Thanks Hrv..I was thinking on the same lines..
I looked at couple other postings on this board on the related issues and got a decent idea about it..

Thanks again.
-Ankur
ankgupta8um is offline   Reply With Quote

Reply

Thread Tools
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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pure conduction problem with different diffusivities diego_angeli OpenFOAM Running, Solving & CFD 2 October 8, 2008 06:53
Diffusivities of species braket FLUENT 1 March 28, 2007 16:45
How to define diffusivities in Fuel cell Model braket FLUENT 1 February 17, 2007 19:08
Scalar Diffusivities A FLUENT 0 December 6, 2004 09:51
UDF: different diffusivities for different uds Elmar Riesmeier FLUENT 1 May 6, 2001 19:53


All times are GMT -4. The time now is 09:26.