SnappyHexMesh& extrudeMesh
 

hi dear fomers, i am working on multi element arifoils, i make the mesh using snappyHexMesh, then for using this mesh with simpleFoam i run "extrudeMesh"
my problem is the cprner of slat that is good till extrudeMesh didn't run.
i put the pictures before and after the extrudeMesh.
any body could help me?
thanks to all:)

Dear saide

look at this post
i think if you add several layers around your airfoil, problem will be solved
on given post there are is a test case which may help you

Hi Dear Nima,
i did what you said me, but i didn't get good results:(
i attach some pictures of the corners of the elements

dear saide :)

1) whats wrong?
2) why just two layers?

Hi Saideh
this error occurred when I run blockMesh on your snappyHexMesh file:

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:eek:dear Nima
be more patient please!
yes its related.
Saideh wanted me help her but I wasn't familiar with snappyHexMesh and the files she gave me displayed an error on blockMesh that I wrote and noticed her to her thread.:)

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I think its better to help her than trying to answer me.:)as I know your posts were irrelevant dear Nima.:pyou didn't know whats the matter and unfortunately now persist on your mistake.its nice that people accept their mistakes than keep them!;)
anyway,please have a look into the error if you can so that I can help her by her case.:)

hi dear nima,
i think what's wrong are those cells that are in the corner of the slat. is it a good mesh for there?

well answer is there: (read error carefully ;))
you can comment those forceDict from controlDict, it can not find it ;) in your system folder

why not ;) but i suggest to increase it to forexample 5 layers and post results here ;), i guess it will improve

Hi Dear ehsan,
yes i forget to put the include function that i had been written in the controlDict of airfoil_snappyHexMesh folder. sorry.
here you are, these are the complete folders in the attachment.
thank you very much :)

Dear Nima,
i don't think so, but I’ll run the snappy with 5 layers now.

dear Saideh in doing this command:
this error displayed:
I'm totally unfamiliar with snappyHexMesh commands if I have run it mistakenly.

Dear ehsan, thank you very much for your kind attention.:)
i put in the attachment the airfoil_snappyHexMesh_modified2 , please open the allrun in this folder, i write in it that you just should run blockMesh and after that snappyHexMesh in two steps as you see in the allrun.txt.

Dear Nima,
these pictures are the results of runningSHM with five layers..

dear saide
check which side of 3D body, are you going to extrude?
are both sides (front and back) are the same?

you're welcome.Saideh it executes fine till extrudeMesh
I don't know why it doesn't open.I use OF 2.2.0

Great! Dear ehsan as i write in the Allrun.txt
after finishing the 2th step of snappHexMesh you should go two the airfoil_simpleFoam_modified that i attach for you, in this folder you should execute "extrudeMesh", after fininshing extrudeMesh, i create polyMesh in the constant folder of airfoil_simpleFoam_modified.
p-s: before running the extrudeMesh in terminal,please copy the name of aifoil_snappyHexMesh_modified2 folder, and past it in front of (sourceCase "../(here)";)) in extrudeMeshDict. after that, execute extrudeMesh.by executing the extrudeMesh, it extrude the mesh that the name of it's folder have been written in front of sourceCase in extrudeMeshDict
tahnk you very much again:)

another error occurred in performing extrudeMesh,I changed that address also:
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I'll continue tomorrow,bye for now :)

Dear ehsan, these two folders "airfoil_snappyHexMesh_modified2" and "simpleFoam_simpleFoam_modified" should be in on folder beside each other.
thanks:)

yes they are in a unique folder beside to each other.
maybe this line have any problem?
is it right? it doen't find controlDict.

after finishig the analysis in airfoil_snappyHexMesh you now have "1,2,3,4" folders, yes?
now go to the airfoil_simpleFoam and write the name of the folder that you run the snappyHexMesh in it that is contain of "1,2,3,4" folders.
after this come to airfoil_simpleFoam that is contain "0,constant,system" and run extrudeMesh, and simpleFoam at the end.

Dear Nima i have extruded the front face, would you please take look at extrudeMeshDict in the attachment?

this error is because of you run the extrudeMesh in a wrong folder. you should go to the airfoil_simpleFoam then run the extrudeMesh there to give you polyMesh, in the constant folder of it.

Hi Saideh
I run the command in true folder but there are only "1,2,3" folders in airfoil_snappyHexMesh_modified2.
which version are you using?
there is an error on snapEdge:
what does do this command?

your extrudeMeshDict are completely right :), did you check your mesh before extrusion? check whether it is front and back are the same

openFoam does not have snapEdge dictionary you should compile it to your openFoam before running the snapEdge in the terminal.
it doesn't necessary for this multi element airfoil. run snappyHexMesh without the snapEdge. so it should create 3 folders for you.

yes i check the mesh, after finishing the SHM. the picture that i put in the 1th post is before layering , after layering and after extrudeMesh.
would you please take a look on my snappHexMesh file?

how to compile snapEdge?
now its running for 30 minutes.
the problem is on the values?
how is the order of coefficients?flap,main,slat from above to bottom?
what is Cl(f) and Cl(r)?

1- i know there is difference in mesh shape before and after extrusion :) you insist on it several times ;), my question was whether front and back face before extrusion after snappyHexMesh have the same shape :D
still waiting for your response :D
2- your snappyHexMesh is fine enough

of course they have the same shape, i attach some picture from front and back views of my snappyHexMesh

i write three function for three element separately, so you should get three group result for "cd, cl and cm" as i know the cl for main element should reach 2.44, and 0.24 for flap.

i have no more clue :) in my mind, be lucky in your simulation,
if you stick in simulation with free software, maybe you want to use other free software such as salome, netgen, gmsh and like that for your simulation :) and import it to OpenFOAM

you mean what is happen after running extrudeMesh is because of my mesh?

i mean that you can create your mesh some where else :D with less sophisticated problem :D

but now, i remember, maybe there is another clue ;)
before, extrude Mesh use following command:
check whether it helps or not :)

Hello,

Did you solve this problem? Because I have the same problem and I can't solve it. I tried to look it up in the forum but nothing new or really helpfull.

Thank you

Dadou

well, you may want to add surfaceFeatureExtractDict to your system folder, and edit it appropriately

Thank you

Regards,