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Re: Front wing - Vortex generators

Posted: 21 Nov 2011, 19:53
by hardingfv32
Now to learn something...

1) Are these vortices of benefit to the front wing or something else downstream?

2) Can they be expected to merge?

3) At what rate does the cone OD enlarge as the vortex moves reward?

4) What is the expect rate of dissipation?

5) Assuming they make their way to the sidepod what is the benefit? I know you expect them to create downforce, but specifically how? Is there any reason to expect the vortices to migrate underneath the side pods? How do you control the vortices off the wing, around the wheel and then underneath the side pod or floor?

Brian

Re: Front wing - Vortex generators

Posted: 21 Nov 2011, 22:46
by shelly
@brian. I have no answer for 3) and 4). For the others my opinion is:

1)yes they produce downforce on the front wing

2) yes they do merge

5) if you get a vortex under a downfacing surfaec, you get downforce, like in my picture of the floor

Re: Front wing - Vortex generators

Posted: 22 Nov 2011, 01:26
by hardingfv32
"5) if you get a vortex under a downfacing surface, you get downforce, like in my picture of the floor"

After leaving the wing is there anything about vortex activity that would predispose them to be drawn toward the ground?

Brian

Re: Front wing - Vortex generators

Posted: 22 Nov 2011, 01:47
by Just_a_fan
hardingfv32 wrote:"5) if you get a vortex under a downfacing surface, you get downforce, like in my picture of the floor"

After leaving the wing is there anything about vortex activity that would predispose them to be drawn toward the ground?

Brian
It's not necessarily that the vortex is predisposed per se but it will be affected by the rest of the airflow around the car. And there are lots of bits on the car designed to get the air, and accompanying vortices, to go where the designer wants them to go.

Re: Front wing - Vortex generators

Posted: 22 Nov 2011, 02:12
by hardingfv32
Just_a_fan wrote: It's not necessarily that the vortex is predisposed per se but it will be affected by the rest of the airflow around the car. And there are lots of bits on the car designed to get the air, and accompanying vortices, to go where the designer wants them to go.
Yes, but is this specific case what would drive the vortices downward toward the entrance of the floors? You have a clear view of the tools being used or available, so take a shot. I can't see how it gets done.

Brian

Re: Front wing - Vortex generators

Posted: 22 Nov 2011, 10:35
by shelly
Vortices do not have to reach the floor to generate downforce: there are the ttray and bargeboard votices for that.
Front wing vortices act on the front wing increasing its downforce and then interact with the flow around the tire and the front suspension arms.

Re: Front wing - Vortex generators

Posted: 22 Nov 2011, 14:40
by DRCorsa
shelly wrote:Vortices do not have to reach the floor to generate downforce: there are the ttray and bargeboard votices for that.
Front wing vortices act on the front wing increasing its downforce and then interact with the flow around the tire and the front suspension arms.
Image

shelly, i understand your statement regarding front wing vortices, but according your picture, there are vortices working on top of the wing, for example 3,4,6.
I understand that vortices no 1,2 and 4 work on the bottom of the wing profiles and actually generating downforce but what about the other vortices? Does they lower the pressure on the top surface of the wing profiles?

Re: Front wing - Vortex generators

Posted: 22 Nov 2011, 15:26
by shelly
With vortices like 3 or 4 ther is not that much you can do. You can use them as flow conditioner for the wheel (3) or maybe make them go under one suspension arm (4).

Bear in mind that these vortices are not generated on purpose, but are instead a side effect of the genaration of downforce by the wing. then the idea is: exploit the side effect to ge some more downforce if possible. If you can get direct downforce, then maybe you cold get some positie influence on elements downstream.

Re: Front wing - Vortex generators

Posted: 22 Nov 2011, 16:18
by DRCorsa
Maybe vortex no4 can be "designed" to go under the nosecone?

Re: Front wing - Vortex generators

Posted: 22 Nov 2011, 16:23
by wesley123
I have the idea number 4 helps in conjunction with the pillars, allowing more air through, increasing downfocre.

What I always had as idea was the these vortices also have an effect on the wheels as well as suspension arms(albeit being too low), might be usesd to reduce drag from the front wheels?

Re: Front wing - Vortex generators

Posted: 22 Nov 2011, 17:51
by miqi23
Vortex number 4 is to manage the flow around the side pods. Its location strongly affects the side pod design. 5 is for the underbody, 6 and 7 is for upper wake management of the front tyres and you see a small delta on the rear wing as a result. 1 goes in board, 2 goes outboard, both to manage the tyre wake.

Re: Front wing - Vortex generators

Posted: 22 Nov 2011, 17:58
by shelly
@miqi: do you think that vortex 4 merges with the top vortex from the bargeboard -or that it flows in the undercutof the side pod - or both?

Nice insight for the other vortices - I agree on 5,6 and 7, but did not expect that 1 went on the inside. Thinking ore about it, it seems logical

Re: Front wing - Vortex generators

Posted: 22 Nov 2011, 18:39
by shelly
Then being 1 and 2 about front wheel wake, they interact with the two squsih vortices from the wheel. Here is yet another reason to get your fornt wing endplate closer to the ground

Re: Front wing - Vortex generators

Posted: 22 Nov 2011, 19:13
by hardingfv32
Before I can evaluate the routing strategies of the front wing vortices, I need to understand the benefit of vortex flow.

I appreciate the benefit of the their low pressure properties, but is not the general flow of a vortex considered turbulent? Is turbulent flow of value in the context of the race car aero? It seems like a lot of the vortices leaving the front wing are just causing turbulence.

Brian

Re: Front wing - Vortex generators

Posted: 25 Feb 2012, 14:02
by shelly
Great post on front wing vortices by Gordon McCabe:

http://mccabism.blogspot.com/2012/02/fr ... tices.html