[TAZ]

Hey there,

i'm getting into OpenFoam (using OF10) and after following few of József Nagy tutorials (god bless this guy) i tried some stuff myself, everything kinda worked until i tried the motorbike tutorial. here's the link: https://www.youtube.com/watch?v=1C4Av_yCfpw
I tried multiple times following the tutorials i foun on YT etc, but no results.
the mesh seems fine, i don't get any error and i can see it using paraview. it seems like there is something wrong either with the initial conditions or with the solver, as at every iteration i get CD, CL, CM all equal to 0 (the velocity is the pre defined 20m/s value).


after building the mesh (blockmesh + surfaceFeatures + snappyHexMesh) and checking with the dummy file in paraview that the mesh is there, i copied everything that's in folder 0 to folder 3 (replacing what is with the same name)
then launching the simulation with simpleFoam, that's the result:
Cm=0
Cd=0
Cl=0
Cl(f)=0
Cl(r)=0

also it seems that the simulation does not converge, as when solving for Ux, it reaches 1000 iterations and then moves on (attached image).

of course when opening paraview, i don't see any pressure or velocity field.
Also, when opening the U or P files, they look weird, likely they are somehow corrupt or something.

it's probably some extremely dumb mistake i'm making, but really cant figure it out!


Attacched:



snappyHexMesh terminal printout
simpleFoam terminal printout
end simulation terminal printout
last timestep result folder
initial conditions (made up) folder


initial_conditions.zip

500.zip

Screenshot from 2023-05-31 12-18-07.png

Screenshot from 2023-05-31 12-09-44.png

Screenshot from 2023-05-31 12-06-36.png

[cfd_site_m]

Same issue
Checked initial condition , p and U files still no change, all coefficients values are 0.

[cfd_site_m]

Number of cells/points in mesh and field don't match

I followed solution by aghora17

1: surfaceFeatureExtract
2:blockMesh
3: In controldict file set the startfrom to latestTime
4: copy polymesh, p,U,k, nut and omega files to dir 1,2 and 3. (do not replace them the existing ones just paste the ones that don't exist)
(extendedFeatureEdgeMesh as well if you are facing issue)

From what I could gather the issue is number of cell discrepancy. And it's supposed to skip the step 0 during solving case and solve from latestTime. Openfoam v6 has startfrom set to laterTime but openfoam v11 has set it to startTime so it'll start from 0.

Also change the 0 file from 0.orig to 0

[fedenr]

Hi,

Have you tried using the "-overwrite" flag when meshing instead of copying the data from one folder to another?

It would be:

snappyHexMesh -overwrite

Then you should have the mesh in the polyMesh folder in constant instead of at new "iteration" folders.


If this doesn't work I would take a look at the name of the boundaries (at polyMesh or using paraview) and then check de initial conditions and forceCoeffs dictionary.