Creation of Downwash

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stevebranson
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Joined: Mon Apr 15, 2019 10:26 am

Creation of Downwash

Post by stevebranson » Mon Apr 15, 2019 10:29 am

Hi,

Just been reading sommersf1's post from 2013 (http://www.somersf1.co.uk/2013/02/f1-sl ... ators.html) and in it he talks about the Ferrari's use of fins on the top of the side pod, and how this produces downwash.

Yet downwash produces lift so why would teams want to do this?

Thanks,
Steve

variante
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Joined: Mon Apr 09, 2012 10:36 am
Location: Monza

Re: Creation of Downwash

Post by variante » Mon Apr 15, 2019 2:25 pm

Because that downwash helps rear devices (floor and rear wing especially) to create more downforce and in a more efficient way. For instance, that trick allows teams to run a rear wing with less AoA and, if needed, more camber.

Lift and downforce don't cancel out because the mentioned sidepod devices can produce a lot of downwash with little lift, while something like the rear wing is extremely effective in downforce production.

jjn9128
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Joined: Tue May 02, 2017 10:53 pm

Re: Creation of Downwash

Post by jjn9128 » Tue Apr 16, 2019 11:44 am

stevebranson wrote:
Mon Apr 15, 2019 10:29 am
Hi,

Just been reading sommersf1's post from 2013 (http://www.somersf1.co.uk/2013/02/f1-sl ... ators.html) and in it he talks about the Ferrari's use of fins on the top of the side pod, and how this produces downwash.

Yet downwash produces lift so why would teams want to do this?

Thanks,
Steve
Careful, downwash doesn't produce lift, downwash is produced by lift. Depending where downwash is produced the effect and severity will be different (e.g. in ground effect downwash is reduced even though lift will be increased).

The fins on the sidepod will be helping flow to cling to the sidepod surface, especially where they sweep downwards agressively - this helps drag and "feeds" air to the diffuser as well as helping the rear wing. Lift/downwash created under the drivers legs helps to draw "clean" air down into the sidepod undercut, and prevents the front suspension wake going into the cooling ducts - it also helps increase the effective angle of the floor, producing more downforce.

A small amount of lift can produce a bigger amount of downforce.
#aerogandalf