Problems in representing convected derivatives in OpenFoam

titio · February 5, 2009, 16:46

Hi all,

I am trying to model the flow of complex fluids in OpenFoam, in particular fluid where normal stresses can be significant. The constitutive equation that I am using, the PTT model, uses a convected derivative, in the form that can be seen in http://en.wikipedia.org/wiki/Upper_c...ime_derivative. That form of derivatives is much used in modelling viscoelastic flows.

I am having problems in representing it in terms of OpenFoam operators. Can anyone help me out. Sorry for not presenting the form of the derivative, but it is to much complex.

António

kerstin · February 16, 2009, 16:01

Hi Antonio,
you need to include the tensor products in the PDE...
maybe this helps

http://www.cfd-online.com/OpenFOAM_D...es/1/6356.html

Kerstin

February 5, 2009, 16:46	Hi all, I am trying to mode	#1
titio Senior Member Antonio Martins Join Date: Mar 2009 Location: Porto, Porto, Portugal Posts: 112 Rep Power: 17	Hi all, I am trying to model the flow of complex fluids in OpenFoam, in particular fluid where normal stresses can be significant. The constitutive equation that I am using, the PTT model, uses a convected derivative, in the form that can be seen in http://en.wikipedia.org/wiki/Upper_c...ime_derivative. That form of derivatives is much used in modelling viscoelastic flows. I am having problems in representing it in terms of OpenFoam operators. Can anyone help me out. Sorry for not presenting the form of the derivative, but it is to much complex. António

February 16, 2009, 16:01	Hi Antonio, you need to inclu	#2
kerstin New Member Kerstin Heinen Join Date: Mar 2009 Location: Ludwigshafen, Germany Posts: 27 Rep Power: 17	Hi Antonio, you need to include the tensor products in the PDE... maybe this helps http://www.cfd-online.com/OpenFOAM_D...es/1/6356.html Kerstin

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Problem in representing term of PDE	titio	OpenFOAM Running, Solving & CFD	1	February 6, 2009 15:28
[General] OpenFoam - problems	MateuszZb	ParaView	8	July 21, 2008 17:16
Representing real length in Gambit	souzan	FLUENT	4	May 20, 2008 05:34
Ld problems with openfoam	srinath	OpenFOAM Installation	1	May 2, 2008 08:49
Representing Efficiency in Wind Turbines	Jenny	FLUENT	1	May 28, 2005 15:34