Aerodynamics effect - air stream effect around a car by bifrost aero

[dolue]

Hi, I would like professional guys in forum to show me how to set up wind stream of aerodynamics effect surrounding a car in a wind tunnel.  I want to express something like smoke.  I want to use Bifrost aero but do you know  how to  set up  wind streamline?  If you gave me any good feedback from you,  I would appreciate you.    I use maya 2018.

Thank you in advance!

[Roland.Reyer]

I don't know how the professional guys would do it.

I once made a wind tunnel scene by using a large box as a volume and as simulation bounds (red arrows).
The car and the ground should then be collision objects.

It is important to set the movement of the volume under "Initial Speed" in the node "source_air" .
This will constantly drive the volume in one direction and the simulation bounds will always cut it off at the other end.

The colored flowlines are displayed with a "volume_scope" node.

I don't know how to create smoke trails.

There is also a "vorticity_influence" node plugged in:

[darioOrtisi]

What's @Roland.Reyer says is correct. There is a way to do some stuff like smoke flowline but it's tricky and complicated and at this point doesn't work like I expected but is a starting point.

After create the big volume(this representing your wind tunnel(fake room) the first volume is for maintain the velocity costantly uniform. After that, take this information to drive your secondary smoke. The principle is that in a wind tunnel the pressure is costant. Aero right now haven't this information to be manipulated.

I will post some example but not soon. Sorry.

[darioOrtisi]

This is something i get.

https://youtu.be/wAWs0Kd7nmI

[Roland.Reyer]

@darioOrtisi That looks great!

Can you share the scene?

[darioOrtisi]

Yes. Let me convert to Y-up axis because we works in Z-up and something disconcerting most of. 🙂

[darioOrtisi]

This is the scene but i cannot convert right now in Y-Up axis. So it's in Z-UP axis. But because there are no boundaries the gravity it doesn't make effects. I will like to make a tutorial, when i have time.

Anyway look at the behaviour creates when changing the subdivision of the plane that is the custom velocity source. The custom velocity affects when it is closest to aero smoke

I will like to get the same effects with volume and velocity from volume but the results right now is totally different and weird.

To be clear, This obviously is similar but non-physical accurated.

[dolue]

Hi Dario and Roland, 

Thank you for nice practical try  for air streaming in Maya and comments!! 

I tried some smoke streamline effects in  the wind tunnel  but it did not work well maybe  my way of doing that was not good.

I appreciate your great support!

[darioOrtisi]

You need more emitters to get streamlines. Usually horizontal at specific height. With multiple steps. 100mm 150mm 200mm 400mm and so on. Did you have a reference to show?

[darioOrtisi]

You can try to do something like that. But there is a problem. The streamlines doesn't take into account the geometry so they not collide to the mesh. So there are copenetration of the streamline even with high flow line samples The volume scope provide only a velocity and other property(the streamlines in this image are from velocity). This is a know issue. It would be great if someone modify the volume scope with a collision detection volume or something like that.