CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Programming & Development

forces code

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 22, 2017, 10:28
Default forces code
  #1
Senior Member
 
A. Min
Join Date: Mar 2015
Posts: 305
Rep Power: 10
alimea is on a distinguished road
Hi
I want to calculate forces for viscoelastic fluid flow. According to what I found out, just I should change the "fT" , i.e. tangential force. in forces.C code we can see:

-etaS*dev(twoSymm(fvc::grad(U)));

for shear stress.

I have three questions:

1- why did it use deviatoric form of twoSymm(fvc::grad(U)) tensor? As you know the shear stress tensor is calculated by:
-etaS*twoSymm(fvc::grad(U))
why deviatoric?!

2- why did it use minus in formula?

3- if I want to add it polymer stress tensor, what should I do? is it enough to write:
(+ or - ??)tau - etaS*dev(twoSymm(fvc::grad(U)));

thanks
alimea is offline   Reply With Quote

Reply

Tags
forces, openfoam, viscoelastic

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
Forces calculated by OpenFoam very strange tta223 OpenFOAM Post-Processing 3 August 5, 2017 09:10
The FOAM Documentation Project - SHUT-DOWN holger_marschall OpenFOAM 242 March 7, 2013 12:30
Reading forces within solver code SD@TUB OpenFOAM Running, Solving & CFD 0 February 28, 2010 18:39
Forces calulated through pressure LVDH OpenFOAM Post-Processing 2 February 26, 2010 03:15
public CFD Code development Heinz Wilkening Main CFD Forum 38 March 5, 1999 11:44


All times are GMT -4. The time now is 13:24.