kastnerp / heatflux

Solving Thermal Bridging Problems for Architectural Applications with OpenFOAM

HeatFlux

This case is based on this paper titled Solving Thermal Bridging Problems for Architectural Applications with OpenFOAM submitted to the SimAUD 2020 conference.

What it does

This may be seen as a framework to assess heat transfer problems which can be automatically generated by Grasshopper.

Abstract

Although recent advancements in computational architecture show promising capabilities, it remains difficult for architects to conduct advanced simulations due to the limited software interoperability. For thermal bridging analyses, the architectural community traditionally relies on specific software tools that are not integrated into a CAD environment. To integrate such analyses into the ongoing design process, we implement a software tool to run heat transfer simulations with OpenFOAM from Grasshopper and Rhinoceros. This paper presents an implementation for box-shaped geometries and compares its results to a thermal bridge analysis from a validated simulation engine. We show that OpenFOAM’s chtMultiregionFoam solver is capable of accurately predicting temperature distributions in a geometry setup with 13 different regions and 8 different materials. In conclusion, we show that heat transfer studies can be highly automated and integrated into an iterative design process.

Geometry used

Results

Temperature distribution

Cross-section temperature plots

How to run the case

• Install BlueCFD in the default folder: C:\Program Files\blueCFD-Core-2017
• Start run_all.bat

Citation

Please cite our work if you decide to use this for your own research.

APA

Kastner, P. and Dogan, T., 2020. Solving Thermal Bridging Problems for Architectural Applications with OpenFOAM. In: SimAUD 2020. [online] Available at: https://www.researchgate.net/publication/346039320_Solving_Thermal_Bridging_Problems_for_Architectural_Applications_with_OpenFOAM.

Bibtex

@inbook{kastner_dogan_2020a, 
 title={Solving Thermal Bridging Problems for Architectural Applications with OpenFOAM}, 
 url={https://www.researchgate.net/publication/346039320_Solving_Thermal_Bridging_Problems_for_Architectural_Applications_with_OpenFOAM}, 
 booktitle={SimAUD 2020}, 
 author={Kastner, Patrick and Dogan, Timur}, 
 year={2020} 
}

heatflux's Issues

OpenFOAM-Grasshopper coupling issues

Hi,

first of all great article and very interesting! however I am quite new in this platfform and using OpenFOAM so i am trying to learn as much as I can.

I want to reply the same than is done in the article but I have a few question in the pre-processing & simultation part for now:

1- how can I assign the values defined in the folders 0 and constant what correspond to boundary conditions and thermal properties to each region (from 0 to 13) in rhino- grasshopper environment?

2- How can I call a .bat file in C# component in grasshopper?

another alternative I have tried is to copy/paste the code for example for "blockmesh"

" setlocal
call "C:\Program Files\blueCFD-Core-2017\setvars.bat"
set PATH=%HOME%\msys64\usr\bin;%PATH% (line 59)
cd /d %~dp0
blockMesh

PAUSE "

in C# component in grasshopper but i get two errors. the error about "" in line 59 can be solved removing the caracter that is located after usr but I don't know if it is right to do it. The other error in line 59 I don't know how to do it. I have read that this line would only work fine for BlueCFD environment and not for windows cmd environment but I am sure I am wrong.

3- Is snappyHexMesh/cfMesh running automatically with OpenFOAM to generate 3d resut visuralization (heat flux)?

4- To run the pre-processing part and simulation then what I have to do this in order:

• first, define the thermal bridge geometry in rhino
• second, assign boundaries conditions and thermal properties to each region
• third, run script in C# for each .bat file

run_blockMesh.bat
run_cellSet.bat
run_splitMesh.bat
run_changeDicts.bat
run_chtMultiRegionFoam.bat

then, at the end, should I see the heat flux-temperature visualization (Figure 4 from the article) or something similar in 3D (I am confused with waht is said in the ast part of the article-conclusions)? do I miss something else in the process?

Regards and thanks in advance

New advance

Hi,

how to convert grad(T)/Magnitud from paraview into W/m2 from your article?

please see the images

the second one is my final result

do you know why the outermost layer (plaster outside) is blue dark?

final run

Hi,

I have an updating. I open "run_blockmesh.bat" and I added " at the end of the file. I dont know but it works, maybe it was luck

when i run the file "run_heatflux.bat" i get the image below at the end. where is it supposed to see the final result (heat flux (W/m2) of the simulation to calculate the lineal thermal bridge?

finally i could run the file "run_all.bat" and generaing the meshes. please see the images if they make sense

Regards

results and visualization

Hi,

Sorry again. I am close to get it . i have done all in grasshopper (image 2)

first of all, I guess that this panel (image 1) should not adapt to my case and leave it as it is

secondly,

I generate the .bat files in my desktop and I double click in the run_all.bat file (image 3) (which includes OpenFOAM’s chtMultiregionFoam solver that is capable of predicting temperature distributions)

Running perfectly but when it fininshes in cdm I cannot visualize the temperature distribution and isotherms (Figure 6 from your article).

1- how can I get those images? image 6.

2- how did you manually calculate the heat flux manually using Fourier's law of heat conduction to every zone in the simulation domain as you explained in your article?
3- is there a way to calculate the lineal thermal bridge (2d)? Typical value enteres in energy simulations

4- after run_all. bar being running, i generate a container which a few elements. which info can I extract from there (image 4)?

Regards

Result and visualization continuation

hi,

1- I have been trying to simulate the case but I do not get any "case.foam" file to visualize in paraview? How can I generate the file?

I have tried to visualize your "openfoam" in paraview and i get the next message. how can I solve it? would the mesh have been generated with blockmesh component?

2- I also run the file "run_heatflux.bat" as you said to me but it stops due to unexpected token. do you know the reason why i get it?

3- what info can i get from "run_plot.bat"?

Regards