Two-sided Wall Heat Transfer BC - No Separate Solid Mesh and No Heat Transfer Coeff
Dear Foamers and Experts,
I have been trying to perform a CFD for compressible internal flow (using rhoSimpleFoam). However, I have been having difficulty implementing the right BC for modelling heat transfer through a 'two-sided' thin wall. The wall does not have thickness (only surface mesh). However, it needs to model heat transfer from one side to another side (this is similar to having a 'shadow wall' in Fluent), without having a separate solid mesh region. Quote:
Additionally, the ability to compute 2D heat conduction in the thin shell is important. All these will need to be achieved without the need to have a separate solid mesh region, and readily implementable with rhoSimpleFoam and rhoSonicFoam solver. I believe no BC is readily available in OF that is able to do this without the need to have a separate solid mesh. I have attempted to model the above requirements using wallHeatTransfer, groovyBC, and fixedGradient, all to no satisfactory result. Could anyone please advice me if this is readily achievable in OpenFOAM without further development of a new BC? Thank you very much in advanced for your response. Best Regards, Stefano Wahono |
Hi Stefano
I think you are right. As I know there in no such a BC in OF. Best regards Good luck Ata |
thin wall conduction
hi
I have a problem with heat conduction through thin wall i have square and in fluent in BC i put thickness and shell conduction for walls and i put heat generation in the square too but after solving, in display contours of temperature i can't see contours of temp in the square and i can't see any thickness that i put for wall.why? could any one help me |
Hi Majas,
I believe you are describing your problem with Fluent. But, unfortunately, this is an OpenFOAM forum. I think you stand better chance to get help if you post in the Fluent forum within the cfd-online.com. Cheers, Stefano |
Hi Stefano,
Were you able to implement the Two-sided Wall Heat Transfer BC ?ak |
Hi ak,
Yes, OpenFOAM 2.0 comes with a two-sided wall BC. Several pre-processing steps are needed to set up this. The following steps solve BOTH the normal heat transfer through the wall and the lateral heat transfer (or shell conduction). Good luck trying. Let me know how you go. Let's say the patch name of your two-sided wall is "wall_duct". Note the following steps work with mesh imported from Fluent format with a "shadow" wall already created in the mesh. The pre-processing: 1. Create a setSet file with the following entries Code:
faceSet fBaffle new patchToFace wall_duct Code:
$ setSet -batch setSet Code:
region baffleRegion; Code:
$ extrudeToRegionMesh -overwrite in your 0/T file: Code:
Add the following in 0/U Code:
fBaffleShadow_top Code:
fBaffleShadow_top Code:
fBaffleShadow_top Code:
fBaffleShadow_top Code:
fBaffleShadow_top Code:
$ mkdir 0/baffleRegion Make a new directory under the system directory: Code:
$ mkdir system/baffleRegion Code:
/*--------------------------------*- C++ -*----------------------------------*\ Code:
/*--------------------------------*- C++ -*----------------------------------*\ Code:
$ changeDictionary -literalRE The system/baffleRegion/fvSchemes look like this: Code:
/*--------------------------------*- C++ -*----------------------------------*\ Code:
/*--------------------------------*- C++ -*----------------------------------*\ Create a new file constant/thermoBaffleProperties Code:
/*--------------------------------*- C++ -*----------------------------------*\ Create a new file inside this new subdirectory constant/baffleRegion/solidThermophysicalProperties Code:
/*--------------------------------*- C++ -*----------------------------------*\ In this example I use rhoSimpleFoam Copy the entire directory of $FOAM_SOLVERS/compressible/rhoSimpleFoam into a new directory $FOAM_SOLVERS/compressible/rhoSimpleBaffleFoam Add the following line in your $FOAM_SOLVERS/compressible/rhoSimpleBaffleFoam/rhoSimpleBaffleFoam.C Code:
#include "simpleControl.H" Code:
autoPtr<regionModels::thermoBaffleModels::thermoBaffleModel> baffles Code:
baffles->evolve(); Change the Make/files Code:
rhoSimpleBaffleFoam.C Code:
EXE_INC = \ Code:
$ Allwmake I hope that helps! Kind regards, Stefano |
Hi Stefano,
Thanks so much for the detailed reply! This should be very useful! Currently I am using OF 1.7.1 but will be upgrading to the newer version, and will post once I have results. Thanks again, ak |
Hi,
I am following a similar process but when I use extrudeToRegionMesh -overwrite I got the following error: --> FOAM FATAL ERROR: Zone walls is not consistently all internal or all boundary faces. Face 107868 at (-4 0.1 -3.9) is the first occurrence. From function checkZoneInside(..) in file extrudeToRegionMesh.C at line 439. FOAM exiting Do you have an idea about how can I solve this? Regards, Karla |
two sided wall in openfoam
Hi karla mora
I m new to openfoam. I m using openfoam 2.3 i would like to know if u could able to solve the error and procceed further. Its a very interesting topic to simulate two sided walls in openfoam . could you please share your experience and challenges u faced. it would be a real contribution. Thank you. regards, Naresh |
Two Sided Wall Heat Transfer for Incompressible Flow
I was initially excited when I stumbled upon this post, however I don't think this solution works for my case. I am trying to implement a baffle into a meshed region, and have the baffle affect the flow (act as a wall) but then not affect heat transfer between fluids; I am also using incompressible flow.
Basically, I have added heat transfer to pimpleFoam and I want to track heat transfer across the baffle assuming it is of near zero thickness (no conduction thermal resistance). I successfully added a baffle into the fluid, and have the baffle redirecting flow. However, I had to make the temperature BC zeroGradient for the simulation to run, so it isn't calculating heat transfer across the baffle. I experimented with mapping the baffle master to slave, but didn't really get anywhere with that. Does anyone know of a way in which to do this? |
Brian,
I dont think you need to apply baffle BC. Two separate wall BC should work in your case. |
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