Diffuser footplates

[turbof1]

Hello dear members,

I was going to write a new article about the updates on the Mercedes W07 front wing, but I hit a bit of stumble. I was going to involve explaining this partly at the hand of diffusers (current outboard f1 front wings and diffusers have a lot in common). At one point a question arose about a specific part of the diffuser: what role does the footplate forfill specifically in relation to the diffuser?

I know it will have to do with the diffuser dominated vortices, which generates massive amounts of downforce. The vortex is able to form due interaction with the diffuser fence/endplate. This I understand, but I can't seem to figure out the essence of the horizontal footplate, nor am I able to find information on this. It is however obviously a very important part as teams are willing to sacrifice diffuser volume in order to have a footplate.

For the record, this is what I mean with the footplate:
https://www.dropbox.com/s/k5sro1nat7lyr ... 1.png?dl=0
The drawing represents a simplified, cross-sectioned floor with diffuser (red). The blue part is the extended floor next to the diffuser, acting as footplate.

[ArgyrisB]

I would say that the footplate creates a vortex that seals the diffuser from the rear tyre squirt that goes inside the diffuser and "destroys" the flow, especially in cornering conditions, just as the front wing footplate seals the front wing.

[godlameroso]

Funny you mention this, when you consider this

Almost no foot plate.

Same here

Only the fins acting as horizontal end plate.

In fact Ferrari has very small end plates as well



In fact Mercedes seems to be the one with the biggest foot plate



I wonder why the trend, also next year will be interesting to see if they follow the trend or go for a more traditional approach.

[turbof1]

Funny you mention this, when you consider this https://1.bp.blogspot.com/-TvV3069wG-w/ ... 419707.jpg

Almost no foot plate.

Same here http://www.formula1.com/content/fom-web ... medium.jpg

Only the fins acting as horizontal end plate.

In fact Ferrari has very small end plates as well

http://cdn-9.motorsport.com/images/amp/ ... sf16-h.jpg

In fact Mercedes seems to be the one with the biggest foot plate

https://i.imgsafe.org/457a0b4865.jpg

I wonder why the trend, also next year will be interesting to see if they follow the trend or go for a more traditional approach.

You are looking at the diffuser exit; you have to look at the diffuser troat. In all cases there will be footplate area.

[wesley123]

The diffuser in that area isn't full width to reduce the negative effects the wheels have on the aero in that area. It was a common practice in 2000-2005 LMPs to not have the diffuser full width.

Without the footplate there would be a large area of nothing, an area where air essentially can flow freely. I'd say the purpose of the footplate(and certainly the original idea was) is to stop air flowing in. Nothing more, nothing less. While these devices have seen some large developments which probably sheds some nice vortices and whatnot it's basic purpose is (afaik) to simply stop air from flowing in.

[Vyssion]

The diffuser footplate used to be used by Ferrari to push the exhaust plume down inside the diffuser to energize the flow back in the days when it was allowed - it had a little flick up which was optimized to do this (see picture). They are also sometimes used to create a vortex to fend off the turbulent wake coming off the rotating wheel.

There also exists one method of using the footplates now that I know of whereby one of the six vortices that a rotating wheel generates (the lower inner one) is contained within the space between the footplate and the ground plane. This vortex acts as a sort of "virtual barrier" which has the implication of sealing off the diffuser exit as if there were side skirts present. Obviously, not to the same degree; however, somewhat successfully.

[PlatinumZealot]

Hello dear members,

I was going to write a new article about the updates on the Mercedes W07 front wing, but I hit a bit of stumble. I was going to involve explaining this partly at the hand of diffusers (current outboard f1 front wings and diffusers have a lot in common). At one point a question arose about a specific part of the diffuser: what role does the footplate forfill specifically in relation to the diffuser?

I know it will have to do with the diffuser dominated vortices, which generates massive amounts of downforce. The vortex is able to form due interaction with the diffuser fence/endplate. This I understand, but I can't seem to figure out the essence of the horizontal footplate, nor am I able to find information on this. It is however obviously a very important part as teams are willing to sacrifice diffuser volume in order to have a footplate.

For the record, this is what I mean with the footplate:
https://www.dropbox.com/s/k5sro1nat7lyr ... 1.png?dl=0
The drawing represents a simplified, cross-sectioned floor with diffuser (red). The blue part is the extended floor next to the diffuser, acting as footplate.

The foot plates are there to keep the diffuser "sealed" from the influence of the rear wheels. They do it by creating or manipulating vortices and sometimes as simple guides and shields. They take up space and seemingly sacrifice diffuser volume, but if they were not there even if the diffuser was the full width it would not generate as much downforce.