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

Implementation of orthotropic thermal effects in tractionBoundaryGradient class

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   November 13, 2014, 14:59
Default Implementation of orthotropic thermal effects in tractionBoundaryGradient class
  #1
Member
 
A. Bernath
Join Date: Jun 2011
Location: Karlsruhe, Germany
Posts: 39
Rep Power: 10
derkermit is on a distinguished road
Hello,
I've modified the elasticOrthoSolidFoam solver such that it accounts for thermal residual stresses because I got oscillations in the stress and epsilon fields which seems to be introduced by the BC. The thermal contribution has to be incorporated into the tractionBoundaryGradient class in order to get the BC's right but that hasn't been done for orthotropic boundaries so far.

My implementation in tractionBoundaryGradient.C (foam ext 3.1) looks like this:

Code:
// Thermal effects
        if
        (
            patch.boundaryMesh().mesh().objectRegistry::
            foundObject<thermalModel>("thermalProperties")
        )
        {
            const thermalModel& thermo =
                patch.boundaryMesh().mesh().objectRegistry::
                lookupObject<thermalModel>("thermalProperties");

            const fvPatchSymmTensor4thOrderField& C =
                patch.lookupPatchField<volSymmTensor4thOrderField, symmTensor4thOrder>
                (
                    "rheologyLawStoredC"
                );

            const fvPatchSymmTensorField& alphaOrtho =
                patch.lookupPatchField<volSymmTensorField, symmTensor>
                (
                    "alphaOrtho"
                );

                if (incremental)
                {
                    const fvPatchScalarField& DT =
                        patch.lookupPatchField<volScalarField, scalar>("DT");

                    gradient += n & (C && (alphaOrtho*DT));
                }
                else
                {
                    const fvPatchScalarField& T =
                        patch.lookupPatchField<volScalarField, scalar>("T");

                    const scalarField T0 =
                        thermo.T0()().boundaryField()[patch.index()];

                    gradient += n & (C && (alphaOrtho*(T - T0)));
                }
        }
I pretty much just copied most of the code from the isotropic part (which actually contains a bug at line 554 which should be true for incremental solvers) and changed the calculation of the contribution to the gradient. alphaOrtho is a symmetrical tensor with the orthotropic thermal expansion coefficients.

I'm running a simulation right now to compare the results but was wondering if someone else has already tried this and can give me some feedback wether this implementation is correct or not.

EDIT: Looks like the stress oscillations are gone =) However the cpu time increased by about 11%...

Thanks, Alex
derkermit is offline   Reply With Quote

Old   November 16, 2014, 07:24
Default
  #2
Super Moderator
 
bigphil's Avatar
 
Philip Cardiff
Join Date: Mar 2009
Location: Dublin, Ireland
Posts: 790
Rep Power: 26
bigphil will become famous soon enoughbigphil will become famous soon enough
Hi Alex,

As far as I can see, the way you are doing it should be correct.
Is it possible for you to share your solver and a simple case? And the tractionBoundaryGradient.C file?

Philip
bigphil is offline   Reply With Quote

Old   November 17, 2014, 07:34
Default
  #3
Member
 
A. Bernath
Join Date: Jun 2011
Location: Karlsruhe, Germany
Posts: 39
Rep Power: 10
derkermit is on a distinguished road
Hi Philip,
that would be possible but I have to clean things up before that...

Thanks for checking the code.

Alex
derkermit is offline   Reply With Quote

Reply

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
Enhanced Wall Treatment - Thermal Effects Brian Tang FLUENT 1 November 6, 2015 00:59
IAPWS water properties + orthotropic thermal conductivity Chander CFX 1 February 29, 2012 18:26
Combining Cavitation and Thermal Effects? akash_max CFX 4 January 19, 2012 15:09
Errors running allwmake in OpenFOAM141dev with WM_COMPILE_OPTION%3ddebug unoder OpenFOAM Installation 11 January 30, 2008 21:30
Info: Short Course On Thermal Design of Electronic Equipment Arnold Free Main CFD Forum 0 August 10, 1999 11:18


All times are GMT -4. The time now is 21:16.