Feeding more air to the diffuser

Here are our CFD links and discussions about aerodynamics, suspension, driver safety and tyres. Please stick to F1 on this forum.
Post Reply
Darknight
0
Joined: 11 Feb 2010, 09:21
Location: Bahrain

Feeding more air to the diffuser

Post

I have been thinking about how a lot of teams run lots of rake on their setups and i assume it is to add more volume under the car to ensure enough air is feeding the diffuser. Also every team is trying to find ways of feeding the diffuser either by EBD or other solutions. Since the rules have clamped down on feeding the diffuser from the top of the floor, has any team experimented with feeding the diffuser by way of the the rear wheels?

The wheel sits above and below the floor, it also has to have air pass through it to cool the brakes. I assume the air goes from the inside of the wheel and exits outside the wheel. What if a solution was found to cool the brakes by having the air enter through the outside of the wheel, cool the brake, then exit from the lower part of the wheel into the diffuser area?

stez90
8
Joined: 10 Jul 2012, 23:31

Re: Feeding more air to the diffuser

Post

you need more volume under the "nozzle" of the diffuser (higher flow rate -> higher speed -> lower pressure), not behind it..

Wideband mindeD
0
Joined: 24 Aug 2012, 21:55

Re: Feeding more air to the diffuser

Post

I think he means to seal the edges along the long axis. Like creating a vortex seal with heated air from the brake ducts.

fynrd1
0
Joined: 15 Apr 2012, 11:52

Re: Feeding more air to the diffuser

Post

They already do that (I expect) by seperating the diffuser flow and the flow allong and from the brakeducts with the rearwing strakes.

gixxer_drew
29
Joined: 31 Jul 2010, 18:17
Location: Yokohama, Japan

Re: Feeding more air to the diffuser

Post

Rake isnt quite rake either....

What would the rake be on the same car at speed if theres a bunch of downforce (rear biased) and the front springs are stiffer relative to the rear?

bigpat
19
Joined: 29 Mar 2012, 01:50

Re: Feeding more air to the diffuser

Post

gixxer_drew wrote:Rake isnt quite rake either....

What would the rake be on the same car at speed if theres a bunch of downforce (rear biased) and the front springs are stiffer relative to the rear?
F1 cars ARE generally setup with stiffer front springs as standard.... The softer rate at the rear obviously lets it compress easier. At high speed, the rake will still be nose down by 5-10 mm.

An F1 car will always have more rear downforce, or else it would be impossible to drive. Downforce ratios are generally a touch more rear biased than the static weight distribution. Less front balance on the front a high speed track, and more on slower, or more "point and squirt" tracks.

The recent cars used EBD to seal the the sides of the diffuser, to stop air migrating under the car. That's what the sharp, bevelled edges on the sides of the floor are there for.Also by raising the rear ride height, you effectively lower the front wing, which has a number of knock-on benefits, and allows the front edge of the rear tyre to close the gap to the floor, helping to reduce leakage further. everything has to be considered as part of a system, not in isolation... in my opinion anyway!

gixxer_drew
29
Joined: 31 Jul 2010, 18:17
Location: Yokohama, Japan

Re: Feeding more air to the diffuser

Post

bigpat wrote:
gixxer_drew wrote:Rake isnt quite rake either....

What would the rake be on the same car at speed if theres a bunch of downforce (rear biased) and the front springs are stiffer relative to the rear?
F1 cars ARE generally setup with stiffer front springs as standard.... The softer rate at the rear obviously lets it compress easier. At high speed, the rake will still be nose down by 5-10 mm.

An F1 car will always have more rear downforce, or else it would be impossible to drive. Downforce ratios are generally a touch more rear biased than the static weight distribution. Less front balance on the front a high speed track, and more on slower, or more "point and squirt" tracks.
Well yah, thats what Im getting at. Almost all downforce cars are just like that. I guess you know the aero figures and spring rates then? Don't forget undulations on the track as well. All I'm saying is that aero is as much about having an amount of forces as it is having them well behaved.

I cant say exactly what happens to an F1 cars forces because I dont know. But this is one factor I know that must surely be relevant to some extent. On the cars I work on, we run rake for that purpose and simply because it makes frontal downforce on a rules flat bottom between the axles but F1 front wings are adjustable and I'm guessing that everything aside from the rules step section could be angled if they wanted it to be?

wesley123
204
Joined: 23 Feb 2008, 17:55

Re: Feeding more air to the diffuser

Post

How is tthis solution going to help? Teams always try to reduce the effect of tyre squirt on the diffuser, and you want that air injected into that area? I think it's clear that that isnt going to help.
"Bite my shiny metal ass" - Bender

Post Reply