Learning Forum

[Dilini]

Hello,

I am studying the flow around a rigid tire.

When I keep a gap between the tire and the pavement, I can create a surface using the sketch as below in design modeler.

But when there is no gap in between the tire and the pavement, I cannot create this surface. 

Error comes saying 'Intersecting profiles are not allowed for 3D features' and 'Invalid feature data -> no closed profiles'

I really need to study the case where there is no gap between the tire and pavement. How can I do this? Please help.

Thank you !!

[peteroznewman]

You must move the circle down a small distance and trim away the part below the line so there is a small flat at the bottom of the tire.

[Dilini]

Thank you. Yes when I do so I am able to create the surface. But in that case I would lose the chance to study the hydrodynamic pressure that gets created lot closer to the touching point.

But I sense there is no other way to do it right? When the tire and pavement is tangentially meeting there is no way to create the surface?

Thanks for your help.

[Rob]

Correct: the geometry definition of the contact point is what causes a non-manifold body.  If you go and look at a car you'll see there is a finite contact between the tyre & road so Peter's suggestion is physically valid as well as necessary for the CAD. 

[Dilini]

Thank you both of you. I could proceed when I did that.

Since I am new to Fluent, I would like to seek some additional support.

I gave two velocity inlets for air and water and defined the pavement as a moving wall with same velocity as water and air and kept my tire stationary. But when I get my volume plot my water goes around the tire unrealistically like in the figure. I cannot see the stagnation of water in the front of the tire. I used the k epsilon model. Any suggestions why I am getting this? I would like to get this clarified before moving to a 3D profile.

I used realistic water height and tire dimensions as well.

[peteroznewman]

Wouldn't you get more water in front of the tire if you had a rotationally moving wall on the tire that matched the velocity of the pavement?

[Dilini]

I have been using a really high velocity. I reduced the velocity and gave a rotational motion to wall that would match the pavement velocity. As you said I could get the stagnation at the front of the tire.

I will try to develop this in 3D so that I can study the side flow as well.

Many thanks for your help.

[Rob]

Which way is gravity pointing?

[Dilini]

It's downwards. I gave -9.81 since the positive y axis is pointing upwards.

[ashmax]

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Why am I facing this issue as invalid profile selection

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