CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > General Forums > Main CFD Forum

Degrees of freedom of a domain

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 21, 2017, 15:45
Default Degrees of freedom of a domain
  #1
Member
 
Katt
Join Date: May 2017
Posts: 30
Rep Power: 9
Katt is on a distinguished road
Hi;

This is a question out of curiosity after a discussion with my friend.

If I have a domain that is spatially discretized, how can I compute the number of degrees of freedom that I have? Does this depend on the staggered or collocated grid arrangement or is only dependent on the domain geometry and spatial discretization?

What is the significance of knowing the number of degrees of freedom in general?

Thanks;
Katt
Katt is offline   Reply With Quote

Old   May 21, 2017, 15:53
Default
  #2
Senior Member
 
Filippo Maria Denaro
Join Date: Jul 2010
Posts: 6,897
Rep Power: 73
FMDenaro has a spectacular aura aboutFMDenaro has a spectacular aura aboutFMDenaro has a spectacular aura about
In this case, degree of freedom and number of unknowns can be considered synonymous...
FMDenaro is offline   Reply With Quote

Old   May 21, 2017, 21:03
Default
  #3
Senior Member
 
Lucky
Join Date: Apr 2011
Location: Orlando, FL USA
Posts: 5,761
Rep Power: 66
LuckyTran has a spectacular aura aboutLuckyTran has a spectacular aura aboutLuckyTran has a spectacular aura about
Degrees of freedom is a measure of how complex or costly your computation is. It's a better measure than just cell count, because you can have a large grid and solve only a few number of transport equations, or you can have a small grid an d solve any equations. When you include chemical reactions for example, the number of species transport equations needed can increase very quickly. It also helps to count between scalar equations, vector equations, and tensor equations. When you only count by cells, these things don't show up.
LuckyTran is offline   Reply With Quote

Reply

Tags
degrees of freedom


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
Monte Carlo Simulation: H-Energy is not convergating & high Incident Radiation volleyHC CFX 5 April 3, 2016 06:41
[snappyHexMesh] No layers in a small gap bobburnquist OpenFOAM Meshing & Mesh Conversion 6 August 26, 2015 10:38
Setting rotating frame of referece. RPFigueiredo CFX 3 October 28, 2014 05:59
six degrees of Freedom.. NEED HELP! DLC OpenFOAM 0 July 29, 2010 09:57
Degrees of freedom NGUYEN Viet Hung FLUENT 0 July 9, 2006 20:59


All times are GMT -4. The time now is 08:25.