Learning Forum

[justnarendra]

hello ansys world   i want to do the aerodynamic simulation of car model in ansys fluent but i am not able to creat the mesh.   please find the STEP file with this post and let me know what steps should follow.   many thanks in advance

[Keyur Kanade]

Hi, 

Can you please insert images. As ANSYS employee, we can not download attachments. 

Also please have a look at following video which can help you to mesh. 

Regards,

Keyur

[justnarendra]

hi . soon i will upload the pics but at the moment i am not able to see the video link 

[justnarendra]

https://grabcad.com/library/the-lamborghini-terzo-millennio-concept-car-1 this is the link of the step file from grab cad 

[Karthik R]

Hello,

Here are some video related to meshing a car using Workbench meshing.

Please see if you can use them to learn how to mesh. Also, as per Keyur's suggestions, please share some more details about your geometry and we can provide more specific instructions.

Thank you.

Best Regards,

Karthik

[Keyur Kanade]

Thanks Karthik, I forgot to share link for video. 

[justnarendra]

hi here are some screenshots please let me know how should i proceed 

[justnarendra]

please find the geometry above

[justnarendra]

please find the geometry above

[Rob]

Hard to tell but it looks like you've got a volume and the car is a collection of surface bodies. This will mesh, but possibly not as you intend. Also, if you read the error message I think (hard to read) that you've got some poor surface cells. Have a look at the surfaces and do some clean up. 

[justnarendra]

[justnarendra]

do i need to close the car body and what about the contacts ?

[Rob]

Depends on what you're trying to achieve: Cars tend to be closed (unless they're convertibles) and contacts means you didn't create multibody parts. 

Looking through the errors, line two is the most useful: have you got very small faces on the car or sharp angles on the surfaces?

[justnarendra]

this geometry has 18 parts which are small and few are large as well and 40 contact regions 

[justnarendra]

https://grabcad.com/library/audi-r8-mesh-2d-1 is the link of the geometry 

[Keyur Kanade]

Hello, 

If you want aerodynamic study as shown in video, please create a solid out of surfaces. Then create outer domain and use subtraction to get fluid domain. 

Please try to start with simple shape as shown in the video. Get familiar with the procedure. Then use your geometry. 

Regards,

Keyur

[justnarendra]

the mesher did not generate any nodes what does it mean ? and tried but i am not able to generate solid out of surfaces any tutorial which might help me ?

[Rob]

Have a look at the surfaces and see if they create a sealed volume: assuming they don't what do you need to do to close it?  I doubt there is a specific tutorial, but have a look at the DesignModeler examples. 

[justnarendra]

thanks

[Keyur Kanade]

Hi, 

For closing that car body, you may need to create some more faces so that it can have a closed region. After than please use body operations - stitch command in DM to create solid body.

Regards,

Keyur

[Keyur Kanade]

Sorry, its 'sew' and not stitch. 

Regards,

Keyur

[justnarendra]

thanks keyur

[justnarendra]

Operation would result in non-manifold bodies i am getting this error.   i closed all the bodies but still i am not able to creat boolean 

[Keyur Kanade]

Did you get a solid in model tree?

Go to tools -- analysis tools -- fault detection. Check if geometry has any faults. 

Regards,

Keyur

[justnarendra]

[justnarendra]

please take a look ...

[Keyur Kanade]

Use Create - Thin Surface and faces except the faces which are giving problem of self intersection. Use thickeness of zero. 

Then recreate those faces to patch the hole. Then again use sew command to create solid. 

Regards,

Keyur

[justnarendra]

hi Keyur as u said i am using very simple geometry at this time but still i am not able to creat the domain please take a look again and there is no fault in the geometry

[Keyur Kanade]

From images, it is still a surface body. Please use sew operation only for surfaces. Please suppress line bodies. 

Regards,

Keyur

[justnarendra]

[justnarendra]

still i am not able to creat thin surface

[Keyur Kanade]

Looks like you already of surface body. 

Regards,

Keyur

[justnarendra]

hi now i created a solid body and i am also able to create boolean but can not transport the geometry to mesh 

[justnarendra]

it is a plug in error 

[Rob]

Try to link to a new mesh component. It's possible the workflow has corrupted with all of the changes. 

[Keyur Kanade]

I see that it is already a surface body.

What you need to do is following - 

Use Sew operation to create a solid body of this surface body. 

Then create outer domain and use boolean operation for subtract.