Another problem case (solved and updated)

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r.tec
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Another problem case (solved and updated)

Postby r.tec » Thu Jan 21, 2021 11:51 am

Hello everybody,

I must say that I am absolutely new to CFD and I want to increase my knowledge just for fun as much as possible.

With the help of Thomas Schrader I manged to get blueCFD, cfMesh and Paraview installed and running.

Now I designed a simple curved channel with
Face1 being the wall
Face2 outlet and
Face3 inlet
013 object.png
013 object.png (59.88 KiB) Viewed 843 times
Then I watched Pawels video on YT and I set the same parameters like he did, except that I took air as the fluid and a velocity of 6 m/s = 6000 mm/s.

Now I go on from the back, i.e. the result of the solver:
001.png
001.png (144.41 KiB) Viewed 843 times
The message in paraview
and
002.png
002.png (183.83 KiB) Viewed 843 times
The message in FreeCAD

The meshed model looks like this:
003.png
003.png (347.02 KiB) Viewed 843 times
with the mesh-parameters:
004.png
004.png (16.39 KiB) Viewed 843 times
The physics model:
004.png
004.png (16.39 KiB) Viewed 843 times
to be continued....
Last edited by r.tec on Tue Jan 26, 2021 1:13 pm, edited 1 time in total.
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r.tec
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Re: Another problem case

Postby r.tec » Thu Jan 21, 2021 11:57 am

Fluid property:
006 fluid property.png
006 fluid property.png (14.06 KiB) Viewed 840 times
Initialise flow field:
007 initialise flow field.png
007 initialise flow field.png (15.76 KiB) Viewed 840 times
Boundary condition wall:
008 boundary condition wall.png
008 boundary condition wall.png (13.49 KiB) Viewed 840 times
Boundary condition inlet:
009 boundary condition inlet.png
009 boundary condition inlet.png (23.54 KiB) Viewed 840 times
Boundary condition outlet:
010 boundary condition outlet.png
010 boundary condition outlet.png (21.8 KiB) Viewed 840 times
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r.tec
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Re: Another problem case

Postby r.tec » Thu Jan 21, 2021 12:00 pm

Mesh refinement:
011 mesh refinement.png
011 mesh refinement.png (17.83 KiB) Viewed 839 times
Mesh case:
012 mesh case.png
012 mesh case.png (12.14 KiB) Viewed 839 times
What do I do wrong?

OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.23683 (Git)
Build type: Release
Branch: master
Hash: af4de262e326452fd79f036253cf7cac6a7e7e00
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: German/Germany (de_DE)
I appreciate any help.
Kind regards,
Helmut
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Re: Another problem case

Postby thschrader » Thu Jan 21, 2021 2:02 pm

Your inlet definition in "Boundary face list" is wrong. Face 1 is the tube, should be Face 2
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r.tec
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Re: Another problem case

Postby r.tec » Thu Jan 21, 2021 4:38 pm

Thank you Thomas, you made my day after days of frustration.
015 paraview 01.png
015 paraview 01.png (82.92 KiB) Viewed 763 times
016 glyph1.png
016 glyph1.png (207.48 KiB) Viewed 763 times
Now I have to learn how to get these nice arrows in one plane like other simulaltions here have.

Enough to do.....

Thanks again!
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Re: Another problem case (solved and updated)

Postby r.tec » Tue Jan 26, 2021 12:05 pm

Now, that I took out all my mistakes with the help of Thomas I tried another model. This time an inlet-channel of a cylinder head into the cylinder bore. A quite complicated geometry.
U=30 m/s
CFD 30mps 01.png
CFD 30mps 01.png (273.76 KiB) Viewed 691 times
The next step will be to subtract the valve guide and the valve itself from the model and try deploy CFD to the even more complicated geometry.
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Re: Another problem case (solved and updated)

Postby r.tec » Fri Jan 29, 2021 10:21 am

Played a little bit around with Paraview. I am impressed:

Uinlet = 30 m/s, Solver ran for over 7 hours, practically the hole day through (n=1500 iterations)
ezgif.com-apng-to-gif.gif
ezgif.com-apng-to-gif.gif (521.15 KiB) Viewed 600 times
But still have a lot to learn about Paraview. Let's go....
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Re: Another problem case (solved and updated)

Postby r.tec » Wed Feb 03, 2021 9:54 am

Apologies to all if I am nerving but I am so amazed of what is possible with "household means", i.e. a not too up-to-date PC, that I simply have to make an update on this fred.
The valve lift is 10 mm.
Side view
Side view
2021-02-03 side view.gif (833.4 KiB) Viewed 503 times


Unforutunately the top view and the stream line and glyph gif-animations are too large to upload here.

I am absolutely flashed by these CFD possibilities in FC. Thank for everyone who made this come true.
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Re: Another problem case (solved and updated)

Postby r.tec » Fri Feb 05, 2021 10:03 am

..now that I have played around with this I wonder if following would be possible with FC-CFD:

- the output had a pressure of 25inHg (Mercury, roughly 0.85 bar) which is in fact a suction

- get the flow rate on the input in cubic feet per minute (cfm) or in litre per minute or cubic metre per minute

Does anybody know if this could be determined and how to do this?