incorrect results from wallHeatFlux utility

tbhanderi · June 28, 2020, 08:15

Hello,

I am using wallHeatFlux utility to calculate heat flux on wall patches. But when I run the post processing function it calculates heat flux based on the temperature and intital values provided in 0 folder. And copying same values of flux in rest of the solution time steps, however the temperature profile is changing during simulation.

Does anyone know why this post processing function does not calculate heatflux based on temperature field of every time step ?? OR am i missing something ??

command : buoyantSimpleFoam -postProcess -func wallHeatFlux

I have added wallheatflux dictionary file in system folder as given below:

========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Version: v1912
\\ / A nd | Website: www.openfoam.com
\\/ M anipulation |
-------------------------------------------------------------------------------
Description
Calculates the heat-flux at wall patches, outputting the data as a
volScalarField.

\*---------------------------------------------------------------------------*/

type wallHeatFlux;
libs ("libfieldFunctionObjects.so");

executeControl writeTime;
writeControl writeTime;

calculated wallHeatFlux values provided in attachment.

HPE · June 28, 2020, 10:46

Hi,

Do you want to compute `wallHeatFlux` during runtime or as postprocessing operation?

The `postProcess` utility is going to execute `wallHeatFlux` function object on the available solutions based on the settings file you have attached.

tbhanderi · June 28, 2020, 12:04

Hi,

Thank you for your reply.

Yes. I want to calculate "wallHeatFlux" as postprocessing operation.

But as per attached result file, It gives same flux values in all iterations (0 to 1221), However it shouldn't be the same value.

Just to check it's dependance on changing scalarFields(e.g. temperature) over the iterations, I've once deleted the results and tried calculating the "wallHeatFlux" and it gave me the same value.
So wallHeatflux calculation is independant of intermediate time steps results, it only depends on value assigned in 0 folder and that makes no sense. could you please tell me what might be the problem ?

Also please tell me how to calculate it runtime ?

June 28, 2020, 08:15	incorrect results from wallHeatFlux utility	#1
tbhanderi New Member CFDUSER Join Date: May 2020 Location: Germany Posts: 4 Rep Power: 5	Hello, I am using wallHeatFlux utility to calculate heat flux on wall patches. But when I run the post processing function it calculates heat flux based on the temperature and intital values provided in 0 folder. And copying same values of flux in rest of the solution time steps, however the temperature profile is changing during simulation. Does anyone know why this post processing function does not calculate heatflux based on temperature field of every time step ?? OR am i missing something ?? command : buoyantSimpleFoam -postProcess -func wallHeatFlux I have added wallheatflux dictionary file in system folder as given below: ========= \| \\ / F ield \| OpenFOAM: The Open Source CFD Toolbox \\ / O peration \| Version: v1912 \\ / A nd \| Website: www.openfoam.com \\/ M anipulation \| ------------------------------------------------------------------------------- Description Calculates the heat-flux at wall patches, outputting the data as a volScalarField. \---------------------------------------------------------------------------/ type wallHeatFlux; libs ("libfieldFunctionObjects.so"); executeControl writeTime; writeControl writeTime; calculated wallHeatFlux values provided in attachment.

June 28, 2020, 10:46		#2
HPE Senior Member Herpes Free Engineer Join Date: Sep 2019 Location: The Home Under The Ground with the Lost Boys Posts: 932 Rep Power: 12	Hi, Do you want to compute `wallHeatFlux` during runtime or as postprocessing operation? The `postProcess` utility is going to execute `wallHeatFlux` function object on the available solutions based on the settings file you have attached. __________________ The OpenFOAM community is the biggest contributor to OpenFOAM: User guide/Wiki-1/Wiki-2/Code guide/Code Wiki/Journal Nilsson/Guerrero/Holzinger/Holzmann/Nagy/Santos/Nozaki/Jasak/Primer Governance Bugs/Features: OpenFOAM (ESI-OpenCFD-Trademark) Bugs/Features: FOAM-Extend (Wikki-FSB) Bugs: OpenFOAM.org How to create a MWE New: Forkable OpenFOAM mirror

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June 28, 2020, 12:04		#3
tbhanderi New Member CFDUSER Join Date: May 2020 Location: Germany Posts: 4 Rep Power: 5	Hi, Thank you for your reply. Yes. I want to calculate "wallHeatFlux" as postprocessing operation. But as per attached result file, It gives same flux values in all iterations (0 to 1221), However it shouldn't be the same value. Just to check it's dependance on changing scalarFields(e.g. temperature) over the iterations, I've once deleted the results and tried calculating the "wallHeatFlux" and it gave me the same value. So wallHeatflux calculation is independant of intermediate time steps results, it only depends on value assigned in 0 folder and that makes no sense. could you please tell me what might be the problem ? Also please tell me how to calculate it runtime ?