[a_run_91]

Thanks to scipy and stuart for the replies. i will try it..

[samidabest]

i draw the 2d model in the ansys when i did meshing on it, it show 3d figure in mesh but in geometry it show 2d figure.... so what i do...... help me

[benjaminhogan]

Hi Scipy,

I have just checked the link to your PDF and it appears to be no longer working.

I was wondering if you would be able to upload it again as I am looking into exterior automotive aerodynamics too.

Cheers.

Ben,

[gned]

dear scipy,
could you post me a working link for the download of that .pdf you mention ?
thanx

[scipy]

That pdf was just a collection of questions and things I had done up to that point.. It's not really of much use (it wasn't a step by step guide or anything). If you are doing vehicle aerodynamics, you'll be better served by checking out the video tutorials on YouTube (mentioned on the first page of this thread).

[Fabio88]

Hello,

very interesting topic.
I have one question.
I am trying to model an isolated wheel, but I have some issues near the intersection wheel/ground.

I have modelled the contact zone, extruding down the footprint for about 7 mm.

Since I am trying to make a mesh to get a y+ value of about 1, the bl near
the contact zone do not look great and several cells have been modified automatically bt fluent mesh during the staistepping phase.

Do you have any suggestion about it?
I am using the last ratio approach for the ground to have a smoother transition between the wedge and tet zone.

Thanks,

Fabio

[scipy]

You've got two options:

1. decrease the surface element sizes in this region so there's no stairstepping (don't know if WB Meshing has options for max aspect ratio and gap factor of prisms like TGrid does),
2. increase your geometry simplification from 7 mm to something larger... This shouldn't have a large impact on the overall results. My "ground fillets" used to be like 2-3 cm from what I remember.

[Fabio88]

Hi Scipy,

thanks for the suggestion.
I used yesterday the option 1 you mentioned by creating a proximity size function at the extrusion. It reduced the number of "bad" elements.

As you suggested, I will try to increase the extrusion size. Since it is bicycle wheel, I wanted to keep it limited as much as possible since I think it can have a larger influence than in car's wheel.

About the ground, I used a larger number of bl cells than on the wheel: I did so to have a nicer transition between wedge and tet cells at the ground. Do you think is a good strategy or is it better to keep the same number of bl layers between wheel and ground?

Thanks again!

[scipy]

You need to use the same number of prism layers on both parts, otherwise, there's no way in the world to avoid stairstepping..

[Fabio88]

Thanks for the clarification. I just realised I was asking for something which is not really possible