Forces calculation

fusij · October 22, 2010, 12:53

Hello OpenFOAM users&fans,

I am new to OpenFOAM and I am simulating a 2D flow over a cylinder with pisoFoam.

When I am trying to find the forces, the forces.dat file only shows brackets full of zeros. The forces code seen below creates a forces/0 folder where forces.dat is located. I am referring to the right patch in the code. Do you have some suggestions or ideas of what could be wrong?

This is my forces code in my controlDict.h

functions
(
forces
{
type forces;
functionObjectLibs ( "libforces.so" ); outputControl timeStep;
outputInterval 1;
patches (wall);
pName p;
UName U;
log true;
rhoName rhoInf;
rhoInf 1025;
CofR ( 0 0 0 );
}
);

NickG · October 29, 2010, 11:23

Hi

Is your cylinder named wall? If not change the

patches (wall);

line in forces{... } to

patches (whatever you've called it);

Hope that helps

Nick

vkrastev · October 29, 2010, 11:30

If the patch name is correct, try also to remove the lines beginning with pName and Uname: judging by other treads in the forum, these lines can give some troubles in the 1.7.x versions of OpenFOAM.

Regards

V.

Aerospace · October 29, 2010, 11:50

Any one knows if there are problems with force function in 3D multifaces patch?

Thankyou.

fusij · October 29, 2010, 12:38

It was just a stupid mistake, for some reason I had changed my patch name to something else than "wall". It is fixed now, thank you.

October 22, 2010, 12:53	Forces calculation	#1
fusij Member Join Date: Nov 2009 Posts: 56 Rep Power: 17	Hello OpenFOAM users&fans, I am new to OpenFOAM and I am simulating a 2D flow over a cylinder with pisoFoam. When I am trying to find the forces, the forces.dat file only shows brackets full of zeros. The forces code seen below creates a forces/0 folder where forces.dat is located. I am referring to the right patch in the code. Do you have some suggestions or ideas of what could be wrong? This is my forces code in my controlDict.h functions ( forces { type forces; functionObjectLibs ( "libforces.so" ); outputControl timeStep; outputInterval 1; patches (wall); pName p; UName U; log true; rhoName rhoInf; rhoInf 1025; CofR ( 0 0 0 ); } );

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Forces viscous calculation in VWT with OpenFOAM 15x	terrybarnaby	OpenFOAM Running, Solving & CFD	0	November 28, 2008 09:39
Calculation of pressure forces in Fluent	Maharba	FLUENT	2	June 29, 2007 02:14
forces calculation	Chien	CFX	9	June 23, 2005 12:45
Warning 097-	AB	Siemens	6	November 15, 2004 05:41
Calculation of forces	Michal Marcinkowski	Main CFD Forum	2	January 18, 2001 05:37

October 29, 2010, 11:23		#2
NickG Member Nick Gardiner Join Date: Apr 2009 Location: Chichester, UK Posts: 94 Rep Power: 17	Hi Is your cylinder named wall? If not change the patches (wall); line in forces{... } to patches (whatever you've called it); Hope that helps Nick

October 29, 2010, 11:30		#3
vkrastev Senior Member Vesselin Krastev Join Date: Jan 2010 Location: University of Tor Vergata, Rome Posts: 368 Rep Power: 21	If the patch name is correct, try also to remove the lines beginning with pName and Uname: judging by other treads in the forum, these lines can give some troubles in the 1.7.x versions of OpenFOAM. Regards V.

October 29, 2010, 11:50		#4
Aerospace New Member Juanito Join Date: Oct 2010 Posts: 27 Rep Power: 16	Any one knows if there are problems with force function in 3D multifaces patch? Thankyou.

October 29, 2010, 12:38		#5
fusij Member Join Date: Nov 2009 Posts: 56 Rep Power: 17	It was just a stupid mistake, for some reason I had changed my patch name to something else than "wall". It is fixed now, thank you.