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

Boundary Condition for granular temperature Theta

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 1, 2012, 22:08
Default Boundary Condition for granular temperature Theta
  #1
Member
 
Charlie
Join Date: Dec 2010
Location: USA
Posts: 85
Rep Power: 15
cheng1988sjtu is on a distinguished road
Hi,

I'm using twoPhaseEulerFoam, including the kinetic theory. I've decided to create a file to solve the PDE for Theta, i.e the granular temperature, that is, I don't want to use the existing kinetic theory in OpenFOAM, basically, the work is done, and the compilation is OK, however, when I tried to run a case, the error message came out.

The following is how I did that, it's simple, I just create a *.H file, which contain the fvScalarMatrix for Theta:

/**************************/
fvScalarMatrix ThetaEqn
(
fvm::ddt(ss,Theta)
+ ...
==
...
);

ThetaEqn.relax();
ThetaEqn.solve();
/****************************/

The compilation is OK, and the initial file for Theta is defined as:
walls
{
type fixedValue;
uniform 0;
}
inandouthalf11
{
type cyclic;
}
inandouthalf12
{
type cyclic;
}
inandouthalf21
{
type cyclic;
}
inandouthalf22
{
type cyclic;
}
top
{
type fixedValue;
uniform 0;
}
frontAndBackPlanes
{
type empty;
}
/************************************************** ******/

However, When I tried to run the case, the error message is that :

--> FOAM FATAL ERROR:

gradientInternalCoeffs cannot be called for a calculatedFvPatchField
on patch top of field Theta in file "/*/*/*/*/0/Theta"
You are probably trying to solve for a field with a default boundary condition.

From function calculatedFvPatchField<Type>::gradientInternalCoef fs() const
in file fields/fvPatchFields/basic/calculated/calculatedFvPatchField.C at line 186.

FOAM exiting

It seems that the problem is that I didn't define the boundary condition, however, I'm basically following Alberto's work on the boundary condition, that is JohnsonJackson's boundary condition, should I include the boundary condition explicitly in the theta equation file? Does anyone has that kind of experience?

Thanks!
cheng1988sjtu is offline   Reply With Quote

Old   June 2, 2012, 00:15
Default Problem solved
  #2
Member
 
Charlie
Join Date: Dec 2010
Location: USA
Posts: 85
Rep Power: 15
cheng1988sjtu is on a distinguished road
Never mind, it's just due to a stupid mistake,
in createField.H, I initiate Theta in a wrong way, it should be:

volScalarField Theta
(
IOobject
(
"Theta",
runTime.timeName(),
mesh,
IOobject::MUST_READ,
IOobject::AUTO_WRITE
),
mesh
// mesh,
// dimensionedScalar("zero", dimensionSet(0, 2, -2, 0, 0), 0.0)
);

cheers!
cheng1988sjtu is offline   Reply With Quote

Old   July 4, 2016, 16:44
Default
  #3
Senior Member
 
Join Date: Jan 2013
Posts: 372
Rep Power: 14
openfoammaofnepo is on a distinguished road
Dear Charlie,

How did you specify the boundary value of Theta for the inlet of the computational domain?

I found that in my case the iteration step is always high (such as 50, at the first time step it is 1000). Do you also have the same situations?

best regards,
OF
openfoammaofnepo is offline   Reply With Quote

Old   July 4, 2016, 17:00
Default BC for Theta at inlet
  #4
Member
 
Charlie
Join Date: Dec 2010
Location: USA
Posts: 85
Rep Power: 15
cheng1988sjtu is on a distinguished road
Hi OF,

I used zeroGradient for Theta at the inlet, and it worked fine. Also, a good initial condition for Theta field also helps!

Best

Charlie
cheng1988sjtu is offline   Reply With Quote

Old   July 4, 2016, 17:08
Default
  #5
Senior Member
 
Join Date: Jan 2013
Posts: 372
Rep Power: 14
openfoammaofnepo is on a distinguished road
Hi Charlie,

Thank you. What kind of initial field for Theta did you specify?

My case is particle laden flows with inlet particle volume fraction = 4e-4. I am considering if I need to use kineticTheoryModel for the particle turbulence. Is your case also gas-particle flows? What is the volume fraction, so you are using Theta?

Thank you.
openfoammaofnepo is offline   Reply With Quote

Reply

Tags
boundary conditions, kinetic theory, two fluid model

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
Temperature dependant mixed Boundary condition argonaut OpenFOAM Pre-Processing 2 February 15, 2011 12:02
External Radiation Boundary Condition (Two sided wall), Grid Interface CFD XUE FLUENT 0 July 8, 2010 07:49
How to apply the temperature boundary condition on the outside of the mould? alefem FLOW-3D 5 May 25, 2010 06:32
Pressure Boundary Condition Matt Umbel Main CFD Forum 0 January 11, 2002 11:06
boundary condition : temperature J.D.Yoon FLUENT 1 August 29, 2000 05:08


All times are GMT -4. The time now is 20:50.