A new series of 10 tutorials about Freecad CfdOf

A subforum specific to the development of the OpenFoam-based workbenches ( Cfd https://github.com/qingfengxia/Cfd and CfdOF https://github.com/jaheyns/CfdOF )

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techGuy
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Re: A new series of 10 tutorials about Freecad CfdOf

Post by techGuy »

Great series. I just found the playlist the other day. I'm slowly making my way through them. Thanks for sharing them.
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Raedchen_im_System
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Re: A new series of 10 tutorials about Freecad CfdOf

Post by Raedchen_im_System »

Tutorial #11: Simple Combustion with reactingFoam

I'm very excited to announce the latest release: I've recorded a new tutorial about reactingFoam. Methane and air react in a reactor vessel. The "conversion" of the solver from PimpleFoam to reactingFoam and the review of the results with Paraview is shown.

The hottest video I have ever recorded - temperatures above 2000 K were achieved.

The openFoam-tutorial that I used as a template for reactingFoam can be found here:
https://github.com/OpenFOAM/OpenFOAM-6
https://github.com/OpenFOAM/OpenFOAM-6/ ... lowFlame2D

Physics Model: transient, multiple phasis with chemical reactions, viscous, laminar flow
2D Model
Fluid: methane, air, water, carbon dioxide
Mesher: CfMesh
Solver Openfoam: reactingFoam
Link: https://youtu.be/TnPm4SVmdp0
Tutorial #11 Simple Combustion.FCStd
(31.87 KiB) Downloaded 139 times
thschrader
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Re: A new series of 10 tutorials about Freecad CfdOf

Post by thschrader »

Raedchen_im_System wrote: Sat Mar 04, 2023 11:11 pm ...
The hottest video I have ever recorded...
...
Great idea 8-)
Silent24
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Re: A new series of 10 tutorials about Freecad CfdOf

Post by Silent24 »

The super YouTube CFD videos bring me to this forum.

Well done.
Roland Kärnten
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Raedchen_im_System
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Re: A new series of 10 tutorials about Freecad CfdOf

Post by Raedchen_im_System »

Tutorial #12: Simple Combustion with reactingFoam

In addition to my tutorial #11, I have recorded the next tutorial about explosive combustion using reactingFoam.

The openFoam-tutorial that I used as a template for reactingFoam can be found here:
https://github.com/OpenFOAM/OpenFOAM-6
https://github.com/OpenFOAM/OpenFOAM-6/ ... lowFlame2D

The original goal was to set up a simulation similar to combustion in an internal combustion engine. I was only partially able to do this due to the instability of reactingFoam. Nevertheless, I have shown that this type of combustion can be simulated with reactingFoam.

Physics Model: transient, multiple phasis with chemical reactions, viscous, laminar flow
2D Model
Fluid: methane, air, water, carbon dioxide
Mesher: CfMesh
Solver Openfoam: reactingFoam
Link to the video: https://youtu.be/fvdZFCL6DHM
Tutorial#12_ExplosiveCombustion.FCStd
(28.96 KiB) Downloaded 98 times
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Re: A new series of 10 tutorials about Freecad CfdOf

Post by Raedchen_im_System »

Tutorial #13: Kelvin-Helmholtz instability with interFoam

I recorded a new tutorial about the Kelvin-Helmholtz instability. The resulting vortices are awesome.

For this simulation, I tried to use the dynamic refinement, but this leads to an error:
Error Dynamic Mesh Refinement.JPG
Error Dynamic Mesh Refinement.JPG (27.31 KiB) Viewed 16117 times
For this reason I used a very high-resolution mesh with an edge length of 0.5 mm. This increases the computing time on my computer to 2 hours and 44 minutes.

I took the experimental setup from the video by "Sixty Symbols" and the University of Nottingham, it's a video well worth seeing: https://youtu.be/mf_143gkKSQ

Physics Model: transient, multiple phasis, viscous, laminar flow
2D Model
Fluid:water / Sea Water
Mesher: CfMesh
Solver Openfoam: interFoam
Link to the video: https://youtu.be/w7ZKDwps1p4

Please find the model attached.
Attachments
Lektion13_KelvinHelmholtzInstability.FCStd
(15.08 KiB) Downloaded 102 times
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Raedchen_im_System
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Re: A new series of 10 tutorials about Freecad CfdOf

Post by Raedchen_im_System »

Tutorial #14: Simulation of Bubbles with InterFoam

In this video tutorial I tried to simulate air bubbles in water. The result is quite pleasing, but due to the fact that surface tension is not taken into account, the bubbles look different. In this tutorial, a material flow is used for the multiphase simulation with the Interfoam solver, i.e. there is an inlet and an outlet.

Physics Model: transient, multiple phasis, viscous, laminar flow
2D Model
Fluid:water / air
Mesher: CfMesh
Solver Openfoam: interFoam
Link to the video: https://youtu.be/6Z3n_nfo5AU

Please find the model attached.
Attachments
Lesson14_Interfoam_Bubbles.FCStd
(30.93 KiB) Downloaded 99 times
thschrader
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Re: A new series of 10 tutorials about Freecad CfdOf

Post by thschrader »

Raedchen_im_System wrote: Tue Jun 20, 2023 5:58 pm The result is quite pleasing, but due to the fact that surface tension is not taken into account, the bubbles look different.
Thanks for the new video.
Surface-tension: you can edit the sigma-parameter in transportProperties.
surface_tension.JPG
surface_tension.JPG (33.89 KiB) Viewed 15952 times

I ran the sim using a finer mesh + surface-tension, to get a better resolution of the bubbles.
max cell size 0,25 mm, 200000 cells. But there are still bubbles (the blue ones) with a smeared out
alpha-air, so the resolution is still too coarse.
bubbles.JPG
bubbles.JPG (24.48 KiB) Viewed 15952 times
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Raedchen_im_System
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Re: A new series of 10 tutorials about Freecad CfdOf

Post by Raedchen_im_System »

@thschrader : Thank you very much for your comments on the consideration of surface tensions in InterFoam! I linked your post in the description of my YouTube video.
soletto
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Re: A new series of 10 tutorials about Freecad CfdOf

Post by soletto »

Hallo,

can you tell me how to add surface tension?

Thank you in advance!
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