CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Pre-Processing

Changing Boundary Types

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   October 8, 2013, 13:00
Default Changing Boundary Types
  #1
otq
New Member
 
Christopher Hughes
Join Date: Oct 2012
Posts: 27
Rep Power: 14
otq is on a distinguished road
I am modifying the chtmultiregion solver to allow use of highly variable fluids. The major issue I am currently having is that several properties, enthalpy primarily, are using incorrect boundary conditions within the volScalarField. This is caused by the fact that h is based off of the T volScalarField.

Since I am interested in the conjugate heat transfer of the system, I am using the turbulentTemperatureCoupledBaffleMixedFvPatchScala rField for the solid-liquid boundary; however, that is an unnecessary boundary for h. I need to change the boundary type for the h volScalarField to fixedValue.

The reason for this, is that once I start solving the problem, the turbulentTemperatureCoupledBaffleMixedFvPatchScala rField is setting all the wall enthalpy values equal to the temperature values, and tries to match gradients. This causes the enthalpy to be several orders of magnitudes lower than it should be. The end result is that OpenFOAM starts reporting negative temperature values(in a Kelvin scale).

The issue I am having is that I do not know if I should do this within the solver, or within my thermophysical model. I thought that within the solver would be most appropriate, so I did the following within setRegionFluidFields.H of my modified chtMultiRegionFoam solver.

forAll(T.boundaryField(),patchi)
{
if(T.boundaryField()[patchi].type() == turbulentTemperatureCoupledBaffleMixedFvPatchScala rField::typeName)
{
h.boundaryField()[patchi].type() == fixedValueFVPatchScalarField::typeName;
rho.boundaryField()[patchi].type() ==fixedValueFVPatchScalarField::typeName;
psi.boundaryField()[patchi].type() ==fixedValueFVPatchScalarField::typeName;
mu.boundaryField()[patchi].type() ==fixedValueFVPatchScalarField::typeName;
K.boundaryField()[patchi].type() ==fixedValueFVPatchScalarField::typeName;
}
}

It tells me that neither fixedValueFVPatchScalarField, or turbulentTemperatureCoupledBaffleMixedFvPatchScala rField have been declared, even though I explicitly included the related header files to the chtMultiRegionSimpleFoam.C file. I do not know where my syntax errors are.

To summarize: I generate volScalarFields based on temperature, the boundary types from the temperature field are copied into those new volScalarFields. The turbulentTemperatureCoupledBaffleMixedFvPatchScala rField type is causing my solution to be completely nonphysical. I need to swap that boundary type to fixedValue WITHOUT changing the values. All of this is occuring before any calculations occur.

Thank you for your time.
otq is offline   Reply With Quote

Reply


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
Wind turbine simulation Saturn CFX 60 July 17, 2024 06:45
Question about heat transfer coefficient setting for CFX Anna Tian CFX 1 June 16, 2013 07:28
Low Mixing time Problem Mavier CFX 5 April 29, 2013 01:00
boundary types don't appear in boundary condition menu stimpy FLUENT 0 December 15, 2010 04:33
[Commercial meshers] Trimmed cell and embedded refinement mesh conversion issues michele OpenFOAM Meshing & Mesh Conversion 2 July 15, 2005 05:15


All times are GMT -4. The time now is 02:48.