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vignesh_n September 25, 2018 14:07

F1 car simulation
 
What is the purpose of giving rotating boundary conditions for wheel in f1 car simulation ? Would the wheel rotate?

FMDenaro September 25, 2018 14:10

Quote:

Originally Posted by vignesh_n (Post 707454)
What is the purpose of giving rotating boundary conditions for wheel in f1 car simulation ? Would the wheel rotate?




Do you know any car moving without rotating the wheels?? Do not forget that in F1 car the wheels are not covered

vignesh_n September 25, 2018 14:19

Quote:

Originally Posted by FMDenaro (Post 707455)
Do you know any car moving without rotating the wheels?? Do not forget that in F1 car the wheels are not covered

What about in passenger cars?

vignesh_n September 25, 2018 14:23

Why do they prefer to give rotating boundary conditions for wheel?

What does it do?

What if we don't give rotating boundary condition and instead treat it as solid wall boundary?

AliE September 26, 2018 18:48

Hi,

Have you ever tried to simulate the flow around a steady and a rotating cylinder? See the works of Mittal to get the point :) Fluid dynamics is different in the two cases! Separetion point and pressure distribution can be significantly different and also the interaction with the vehicle's body change. This is why the wheels rotation is important, especially if you are doing a simulation for an application where every newton of downforce is important.

coupsdebambous September 26, 2018 21:58

Rotating the wheels will largely complicate your mesh and complexity, but will get you a more accurate flow hitting your downstream part. Mesh adaptation can help quite a bit.


In the case of an F1, it is crucial to get the tire wake right, so sidepods, underbody, diffuser and rear wing all get the correct upstream flow.
That's also why you see such complicated front wings these days: divert that flow around these messy wheels.

vignesh_n September 27, 2018 14:05

Quote:

Originally Posted by coupsdebambous (Post 707755)
Rotating the wheels will largely complicate your mesh and complexity, but will get you a more accurate flow hitting your downstream part. Mesh adaptation can help quite a bit.


In the case of an F1, it is crucial to get the tire wake right, so sidepods, underbody, diffuser and rear wing all get the correct upstream flow.
That's also why you see such complicated front wings these days: divert that flow around these messy wheels.

Shouldn't we specify angular velocity of the wheel if we are giving rotating boundary condition.? But I have seen people not giving it. Instead they just give the relative velocity of the vehicle.


Why most people don't create MRF zone for the wheel as they do for radiator fan ?

What are the various rotating frame off reference and please let me know when to use what?

Thanks in advance.

me3840 October 2, 2018 19:07

Yes, you should specify the angular velocity if you are setting the reference frame at the center of rotation. If your reference frame is elsewhere then it would be different. I'm not sure why anyone would choose anything other than the center of rotation, though. The latter is the simplest way to specify it.



Most people doing serious aero work will create MRF areas for the inside of the wheel and the wheel rim. The tire however just gets a wall velocity specification. Making an MRF zone for the tire in a general was is very complex and usually not done unless you use something like an overset method.


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