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CDG wing concept
Posted: 09 Sep 2009, 15:32
by mach11
can anyone pl explain to me what are the advantages of the CDG rear wing concept???? also i am designing a 600-700 cc single seater races??? which will reach a max speed of 180 kmph.... will this CDG wing concept help in creating more downforce at those speeds????
Re: CDG WING CONCEPT
Posted: 09 Sep 2009, 15:37
by ESPImperium
Re: CDG WING CONCEPT
Posted: 09 Sep 2009, 15:56
by mach11
yeah this very concept.... can i get the report about this design.... also will this design be efficient for a car reaching upto speeds of 180-200 kmph????
Re: CDG WING CONCEPT
Posted: 09 Sep 2009, 16:03
by Scotracer
This wont give you more downforce over a "regular" wing - it was designed to reduce the wake effect that would inhibit close racing. It will produce less downforce than a conventional wing.
Re: CDG WING CONCEPT
Posted: 09 Sep 2009, 17:07
by mach11
was this wing design ever mounted on an F1 car because... i heard that it was mainly used to reduce water spray behind the car during a wet race....
if there was a actual design where can i get the specs ( dimensions) and wind tunnel test data?????????
Re: CDG WING CONCEPT
Posted: 09 Sep 2009, 17:29
by Scotracer
mach11 wrote:was this wing design ever mounted on an F1 car because... i heard that it was mainly used to reduce water spray behind the car during a wet race....
if there was a actual design where can i get the specs ( dimensions) and wind tunnel test data?????????
It was done mainly to reduce the wake signature (but it would help the water spray).
And no, it was never track tested.
Re: CDG WING CONCEPT
Posted: 09 Sep 2009, 19:49
by mx_tifoso
OP, are you going to give these guys credit on your report for helping you out?
Re: CDG WING CONCEPT
Posted: 09 Sep 2009, 20:50
by tok-tokkie
I had never heard of it. What was the history behind it & what got in its way? It looks so appropriate for what the Overtaking Working Group (or whatever they were called) were wanting to achieve.
On the other hand I don't follow how deflecting the airstream downwards was able to generate downforce - don't momentum vectors apply here?
Re: CDG WING CONCEPT
Posted: 09 Sep 2009, 21:21
by Scotracer
tok-tokkie wrote:I had never heard of it. What was the history behind it & what got in its way? It looks so appropriate for what the Overtaking Working Group (or whatever they were called) were wanting to achieve.
On the other hand I don't follow how deflecting the airstream downwards was able to generate downforce - don't momentum vectors apply here?
It was brought about because it was known that the wake off the rear wing and diffuser of a modern F1 car cause low pressure areas for the car following (see ESP's CFD image). This reduces the downforce potential of the following car and as a result, they can get to the car ahead but don't have the grip to pass. So, to resolve this they thought about this "downwash generating wing", which, obviously, creates a downwash instead of upwash. This improves the pressure gradient of the wake.
However
It was found that the two wings behind the rear wheels were extremely sensitive to the wake of the rear wheels and as a result, were not efficient enough to work. The idea was then scrapped.
It was not to increase downforce of the car
using the wing, but improve the grip of the car following.
Re: CDG WING CONCEPT
Posted: 09 Sep 2009, 23:44
by ESPImperium
Scotracer wrote:tok-tokkie wrote:I had never heard of it. What was the history behind it & what got in its way? It looks so appropriate for what the Overtaking Working Group (or whatever they were called) were wanting to achieve.
On the other hand I don't follow how deflecting the airstream downwards was able to generate downforce - don't momentum vectors apply here?
It was brought about because it was known that the wake off the rear wing and diffuser of a modern F1 car cause low pressure areas for the car following (see ESP's CFD image). This reduces the downforce potential of the following car and as a result, they can get to the car ahead but don't have the grip to pass. So, to resolve this they thought about this "downwash generating wing", which, obviously, creates a downwash instead of upwash. This improves the pressure gradient of the wake.
However
It was found that the two wings behind the rear wheels were extremely sensitive to the wake of the rear wheels and as a result, were not efficient enough to work. The idea was then scrapped.
It was not to increase downforce of the car
using the wing, but improve the grip of the car following.
Hence why we now have higher narrower wings. Try and get the downwash thrugh the wing centre zone and with that reduce the efficency of the wing as it is now more narrow. But many cars so far this year have now changed that with the rear crash structure with both the lower elements of the rear wing and their DDDs. Also the flow conditioner that is the shark fin also has something to do with downwash.
Re: CDG WING CONCEPT
Posted: 09 Sep 2009, 23:46
by Scotracer
ESPImperium wrote:Scotracer wrote:tok-tokkie wrote:I had never heard of it. What was the history behind it & what got in its way? It looks so appropriate for what the Overtaking Working Group (or whatever they were called) were wanting to achieve.
On the other hand I don't follow how deflecting the airstream downwards was able to generate downforce - don't momentum vectors apply here?
It was brought about because it was known that the wake off the rear wing and diffuser of a modern F1 car cause low pressure areas for the car following (see ESP's CFD image). This reduces the downforce potential of the following car and as a result, they can get to the car ahead but don't have the grip to pass. So, to resolve this they thought about this "downwash generating wing", which, obviously, creates a downwash instead of upwash. This improves the pressure gradient of the wake.
However
It was found that the two wings behind the rear wheels were extremely sensitive to the wake of the rear wheels and as a result, were not efficient enough to work. The idea was then scrapped.
It was not to increase downforce of the car
using the wing, but improve the grip of the car following.
Hence why we now have higher narrower wings. Try and get the downwash thrugh the wing centre zone and with that reduce the efficency of the wing as it is now more narrow. But many cars so far this year have now changed that with the rear crash structure with both the lower elements of the rear wing and their DDDs. Also the flow conditioner that is the shark fin also has something to do with downwash.
That's not why the wings are now higher and narrower. They are higher to get the low pressure areas above the ground - so not affecting the front wing and diffuser of the car following. They made it narrower to reduce the wake and reduce downforce (which was still a bit deal back then).
The sharkfin is to make the centre of pressure more rearward and help the rear wing efficiency in jaw conditions
Re: CDG WING CONCEPT
Posted: 10 Sep 2009, 08:55
by xpensive
I'm not sure who's idea this CDG was, but I clearly recall that it involved MrM's old business-buddy Nick Wirth, a man who never had much success with anything.
He started the Simtek F1 team in 1994 with title-sponsorship from MTV(!), went broke the following year and as a reward became Chief designer of Benetton 1996-99, where he launched the hopeless "torque-split" at the front.
He will return to F1 as Tech boss with Manor next year, which might xplain why they were granted an entry by MrM.
Re: CDG WING CONCEPT
Posted: 10 Sep 2009, 09:21
by gridwalker
This article may be of interest to you, as it covers the reasons why the CDG was proposed but not adopted and why we ended up with the regs that we have now :
http://www.grandprix.com/ft/ft20831.html
In 2005 FIA President Max Mosley commissioned his former partner Nick Wirth, a designer who had worked with the Simtek and Renault F1 teams, to come up with an idea of how to lower aerodynamic turbulence behind the cars and by doing so create more overtaking. Wirth worked with computational fluid dynamics (CFD) programmes to come up with what he called the Centreline Downwash Generating (CDG) wing. The FIA announced that it would introduce the CDG wing in 2008.
At the time the Technical Working Group, working with the Grand Prix Manufacturers' Association (GPMA) used the Italian Fondtech wind tunnel, run by former Ferrari and Tyrrell aerodynamicist Jean-Claude Migeot, to see if the CDG wing would work. Migeot and his team concluded that the idea was flawed. By the autumn of 2006 no-one had much confidence in the CDG wing and Mosley agreed that its introduction could be delayed and that the Technical Working Group should come up with a better idea for 2009.
Re: CDG WING CONCEPT
Posted: 10 Sep 2009, 10:27
by xpensive
Thanks Grid, most informative piece that. Imagine having MrM as your mentor?
Re: CDG WING CONCEPT
Posted: 11 Sep 2009, 00:19
by Steven
Hi,
you might want to take a look at this page:
http://www.f1technical.net/search/index ... earch#1093
You'd be surprised what you can find here
