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-   -   URGENT: HELP ICEM beginner mesh generation car (http://www.cfd-online.com/Forums/cfx/24649-urgent-help-icem-beginner-mesh-generation-car.html)

guest7777 October 11, 2007 12:46

URGENT: HELP ICEM beginner mesh generation car
 
hello, I want to generate the car mesh and try to solve it in CFX : i am attempting a 2-d case (z-direction 1 cell thickness) for a car with edges and curves. how to generate the mesh around the car ? I /want to tried to have structured blocks but run into problems at corners and so on. PLEASE HELP


Anantha October 11, 2007 14:29

Re: URGENT: HELP ICEM beginner mesh generation car
 
Hello, So vague question.. What exactly is your problem?

guest7777 October 11, 2007 14:57

Re: URGENT: HELP ICEM beginner mesh generation car
 
i have the geometry of the 2d-car: in which manner to create structured mesh (via blocks) around the bends and critical regions? How do i split the initial block around the car body? I have enclosed the car body and put a material point in it. PLEASE HELP URGENT


Glenn Horrocks October 11, 2007 18:25

Re: URGENT: HELP ICEM beginner mesh generation car
 
Hi,

Your question seems to be a pretty basic ICEM-hexa question as you are talking about blocking. Therefore I assume you are fairly new to CFD - please correct me if I am wrong.

For a complicated geometry such as a car you will probably find a tet mesh with inflation layers much easier to generate. It sounds like you are using ICEM-Hexa, that is a much more complicated way of doing it which I would only recommend if you really need a structured hex mesh.

If this really is "urgent" (I wish people would stop saying that, you get a bit sick of it after a while) then I would recommend you use CFX-Mesh. It can generate tet/inflation layer meshes for 3D and extruded meshes with inflation layers for 2D and is MUCH easier to use than ICEM. You will get a decent mesh much quicker in CFX-Mesh than ICEM.

Regards, Glenn Horrocks

guest7777 October 11, 2007 18:34

Re: URGENT: HELP ICEM beginner mesh generation car
 
Thank you very much BUT :( i have to do it with structured grid in ICEM How do i set about this?


Anantha October 12, 2007 01:41

Re: URGENT: HELP ICEM beginner mesh generation car
 
Hello, If you are really new to ICEM-CFD Hexa, I suggest you to go through the tutorials first. It will give you a fair idea about the blocking stratagies, element distribution, etc... In fact there is a tutorial on generating mesh around the car (a 2D car, I think it's 2nd or 3rd tutorial). Practice that and later try to solve your problem.

Regards Anantha

guest7777 October 12, 2007 02:30

Re: URGENT: HELP ICEM beginner mesh generation car
 
thanks for the responses: however is there any way to create structured mesh around a car?

How to go about it???

I am going through the 2-d car example ...

thank you very much

Anantha October 12, 2007 02:43

Re: URGENT: HELP ICEM beginner mesh generation car
 
Hello.. Yes, you can do that very much... and that's what they have shown in tutorial... have some patience, please go through the entire tutorial, practice it and then try your problem... unfortunately there is no 'quick fix' approach available in ICEM, especially ICEM Hexa..!!!

Regards Anantha

guest7777 October 12, 2007 04:30

Re: URGENT: HELP ICEM beginner mesh generation car
 
Thank you but :) will the tutorial help me undesrtand how to create a STRUCTURED mesh around a car?

Anantha October 12, 2007 05:29

Re: URGENT: HELP ICEM beginner mesh generation car
 
What you are taught in the tutorial is to generate a Hexahedral mesh around 2D car. Whether you want that hexa mesh in 'unstructured' format or 'multi block structured' format depends on the way you write the output file. You can see the explanation in User Manual under Hexa > Unstructured and Multi-block Structured Meshes.

guest7777 October 12, 2007 07:17

Re: URGENT: HELP ICEM beginner mesh generation car
 
Thank you, i am looking at is and just created the geometry, with one additional z-layer

i have defined a material point in the car which i hope is recognised as a closed surface

how to overcome the difficulties at bendings and sharp curves of my car model?

thank you, still working :(

Chirag October 12, 2007 07:51

Re: URGENT: HELP ICEM beginner mesh generation car
 
Dear guest7777, Define material point where the flow is. In your case it's outside the car, not inside. BTW, why don't you go through some tutorials? Jumping directly to your main CFD problem may result into not so reliable solution.

Best luck, Chirag

guest7777 October 13, 2007 09:06

Re: URGENT: HELP ICEM beginner mesh generation car
 
tutorials: thats what i am doing now. material point should be in the car (closed surface) not outside ... BUT i just want to know if i can realistically create structured hexa-mesh in ICEM for a car?? There are definitely experts in this forum (great by the way) who have simulated a car and they can give hint as to how to do it? I have a deadline ...


Anantha October 15, 2007 05:25

Re: URGENT: HELP ICEM beginner mesh generation car
 
Hello.... What kind of mesh are you trying? If it is hexa, then there is no need for the material point to be defined. If it is tetra, yes you need to define one. And as Mr Chirag suggested, if you need a mesh outside the car for external flow simulation, the material point should not be inside the car, but outside the car surface.

You can "realistically" create structured hexa mesh around the car. But I understand your case is a 2D and for this surely it is possible to generate the mesh.

What else help are you expecting here in the forum? It's already been mentioned that there is a tutorial for the same. Please try that completely. Once you start working on the actual problem, if you come across any specific issues post it here and then we shall try to address that together.

Anantha


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