Search found 3129 matches

by thschrader
Tue Feb 06, 2024 11:12 am
Forum: FEM
Topic: New blade file with twist and correct foil shape, will not mesh
Replies: 48
Views: 29921

Re: New blade file with twist and correct foil shape, will not mesh

Lt72884 wrote: Mon Feb 05, 2024 3:40 am ...
Thank you for the information. To understand correctly, when you say 10 minutes for computing, thats for the 2D case, not the 3D?
...
Yes, 10 min is the runtime for the 2D-case.
Here is a 3D-case with 8 hour runtime. Give it a try... :mrgreen:
Meshing needs only 1 min.
antennas.FCStd
(153.32 KiB) Downloaded 8 times
by thschrader
Sun Feb 04, 2024 10:11 pm
Forum: FEM
Topic: New blade file with twist and correct foil shape, will not mesh
Replies: 48
Views: 29921

Re: New blade file with twist and correct foil shape, will not mesh

hammax wrote: Sun Feb 04, 2024 12:40 pm ... I tried to redesign this "4 radius profile" with a BSpline contour and Gordon.
blade_reconstruct_2.PNG
Hi hammax,
thanks for jumping in.
Are you sure that the geometry is valid?
blade2_zoom.PNG
blade2_zoom.PNG (162 KiB) Viewed 579 times
blade2.PNG
blade2.PNG (185.9 KiB) Viewed 579 times
by thschrader
Sun Feb 04, 2024 9:42 am
Forum: FEM
Topic: New blade file with twist and correct foil shape, will not mesh
Replies: 48
Views: 29921

Re: New blade file with twist and correct foil shape, will not mesh

... so with a 2d case, i just need the top faces of my blade correct? I have not learned 2d in freecad yet so that will be new as well. Here is an example to get an idea how the setup works. NACA2412 profile, see Report 586 page 7 here: https://ntrs.nasa.gov/api/citations/19930091662/downloads/1993...
by thschrader
Sat Feb 03, 2024 9:41 am
Forum: FEM
Topic: New blade file with twist and correct foil shape, will not mesh
Replies: 48
Views: 29921

Re: New blade file with twist and correct foil shape, will not mesh

Interesting, so i have to create some sort of wind tunnel then. I have been following their approach from downloading the file, but its taking over 2 hours to run the solver in openfoam and for the residuals to finish. Is this normal? I have 12 core cpu and 32gb of ram thanks Yes,cfd is very comput...
by thschrader
Wed Jan 31, 2024 8:33 am
Forum: CfdOF / CFD
Topic: Is it possible to have time based boundary conditions?
Replies: 1
Views: 438

Re: Is it possible to have time based boundary conditions?

There is no option in the cfdof-GUI to define a time dependent inlet patch.
But you can write/edit the case files. Then run solver.
Example (very old):
viewtopic.php?t=29286&start=20
by thschrader
Tue Jan 30, 2024 9:43 pm
Forum: Forum in Deutsch
Topic: Führungspfeiler und Haltepfeiler und ggf. untere Führungsschine für ein untengeführtes Schiebetor dimensionieren
Replies: 3
Views: 1309

Re: Führungspfeiler und Haltepfeiler und ggf. untere Führungsschine für ein untengeführtes Schiebetor dimensionieren

... Besser: FreeCAD Datei mit genauen Abmessungen. Sicher könnte ich das hier hochladen, du würdest es anschließend berechnen und ich würde es beim nächsten Mal wieder nicht verstehen. Nein, ich möchte wissen, was du tust , um es selbst zu machen. ... Ja, ich würde es wieder berechnen. Aber ich kan...
by thschrader
Sun Jan 28, 2024 3:11 pm
Forum: Forum in Deutsch
Topic: Suche Finite-Elemente-Programm für Hobby-Projekte
Replies: 13
Views: 1069

Re: Suche Finite-Elemente-Programm für Hobby-Projekte

2 Möglichkeiten: Grafisch als Krafteck, die blaue Resultierende muß durch den schwarzen Strich an der Fundamentunterkante laufen (Kernfläche, Weite b/3), dann gibt es keine klaffende Fuge und das System ist stabil. Die Reihenfolge der geometrischen Addition der Kräfte ist egal, die Richtung der blau...
by thschrader
Sat Jan 20, 2024 5:29 pm
Forum: FEM
Topic: New blade file with twist and correct foil shape, will not mesh
Replies: 48
Views: 29921

Re: New blade file with twist and correct foil shape, will not mesh

Addendum:
cfd-sim with cfdof-wb, blade exported as step, loaded in prepomax.
OpenFOAM p-field imported into prepomax, static calulation of the blade.
The imported p-field was scaled with 1,25 to account for air density.
Wind speed is 7 m/s (25 km/h).
blade_reconstruct_CFD.FCStd
(388.79 KiB) Downloaded 24 times
blade_cfd.png
blade_cfd.png (286.82 KiB) Viewed 5016 times
by thschrader
Mon Jan 15, 2024 11:05 am
Forum: CfdOF / CFD
Topic: CfdOF gmsh Error : Impossible to mesh periodic surface 4
Replies: 2
Views: 8917

Re: CfdOF gmsh Error : Impossible to mesh periodic surface 4

Hi, I get the same error.
With 2x half torus instead of one it works.
2xtorusMesh.png
2xtorusMesh.png (314.85 KiB) Viewed 8142 times
simple_flow_ts.FCStd
(27.51 KiB) Downloaded 28 times
by thschrader
Sun Jan 14, 2024 3:31 pm
Forum: FEM
Topic: New blade file with twist and correct foil shape, will not mesh
Replies: 48
Views: 29921

Re: New blade file with twist and correct foil shape, will not mesh

Here is my attempt: I have reconstructed the wing with the "Curved-shapes" workbench, see addon-manager or https://github.com/chbergmann/CurvedShapesWorkbench The leading/trailing edges are now tangential to the wing surface. The inner wing part is a simple loft. With GMSH I can produce a ...