Mercedes GP MGP W01

A place to discuss the characteristics of the cars in Formula One, both current as well as historical. Laptimes, driver worshipping and team chatter does not belong here.

Post Mon Dec 06, 2010 9:44 am

oh closed loop vs open loop ....
my favorite.
A hand operated f-duct is nothing else than steering a car or applying throttle.Input is given by human and the system responds to it with a defined answer.so clearly a closed loop as long as no secondary parameters are f.....it up.
If your f-duct is using a secondary input to allow or reject activation -lets say ambient temperatur ,or jaw angle I´m convinced it has open loop capability.
marcush.
 
Joined: 9 Mar 2004

Post Mon Dec 06, 2010 10:20 am

ringo wrote:Yes an active system can be mistriggered, but it would simply stabalize itself; This would come in the form of the driver's input.
An active system simply would not behave erratically as Shu described it.

Renault said that Petrov's crash at practise in Brazil was due to F-duct malfunction that failed to come back into "closed" state.
timbo
 
Joined: 22 Oct 2007

Post Mon Dec 06, 2010 12:06 pm

marcush. wrote:oh closed loop vs open loop ....
my favorite.
A hand operated f-duct is nothing else than steering a car or applying throttle.Input is given by human and the system responds to it with a defined answer.so clearly a closed loop as long as no secondary parameters are f.....it up.
If your f-duct is using a secondary input to allow or reject activation -lets say ambient temperatur ,or jaw angle I´m convinced it has open loop capability.


:lol:

That rules Coulthard out of ever using it....

(sorry, I could resist - believe me I tried).
Nothing is foolproof to a sufficiently talented fool...
NewtonMeter
 
Joined: 24 Jun 2010
Location: Pretoria, South Africa

Post Mon Dec 06, 2010 6:50 pm

timbo wrote:
ringo wrote:Yes an active system can be mistriggered, but it would simply stabalize itself; This would come in the form of the driver's input.
An active system simply would not behave erratically as Shu described it.

Renault said that Petrov's crash at practise in Brazil was due to F-duct malfunction that failed to come back into "closed" state.


Well take note of the word in bold.
It would be nice if any of you here could put up a schematic of the system.
With the actual air path way and plumbing.
For Sure!!
ringo
 
Joined: 29 Mar 2009

Post Mon Dec 06, 2010 6:55 pm

marcush. wrote:oh closed loop vs open loop ....
my favorite.
A hand operated f-duct is nothing else than steering a car or applying throttle.Input is given by human and the system responds to it with a defined answer.so clearly a closed loop as long as no secondary parameters are f.....it up.

Yes, but what about one without driver response?

If your f-duct is using a secondary input to allow or reject activation -lets say ambient temperatur ,or jaw angle I´m convinced it has open loop capability.


The # of inputs aren't the issue, it's the ability to respond to an input an adjust the system accordingly.

There is more evidence suggesting the W01 has an open loop F duct system.
No shots of plumbing exist for this car.

I'm not ruling out active, but there is a stronger argument against it.

Image
Image
be free to indicate where the plumbing is. There just almost zero chances for air to be snaked from the cock pit, beside the gearbox, through the suspension parts and then through the end plate, turning a hard 90 degrees to the slot.
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ringo
 
Joined: 29 Mar 2009

Post Mon Dec 06, 2010 8:16 pm

ringo wrote:It would be nice if any of you here could put up a schematic of the system.
With the actual air path way and plumbing.

OK.
When the car is exposed to high-G's the signal pipe is chocked by being pressed against the bodywork. Is it possible? IMO, yes.
Or when the car is in yaw condition it doesn't work properly.
There's nothing in what Schu said rulling out a malfunctioning active system.
I do think it's passive.
timbo
 
Joined: 22 Oct 2007

Post Mon Dec 06, 2010 10:44 pm

I see your point, but i would not say it is 50/50 either way. There is a 90% chance the system is passive.

Body work should be rigid, so the pipe cannot be squeezed. When the car is in Yaw, it shouldn't have a bearing on the signal pipe.

What shu said or didn't say, is mention of him trying to control the F duct when it's malfunctioning. Don't you find it weird it would be active, yet he never mentions troubleshooting it with his wrist or knee?

All other drivers who had problems with their duct, never complained of erratic behavior, and they always mention their part on the control end.

What I am hoping for is that someone show where the pipe is in this system. We've seen it for every team running an F duct but Mercedes.
Secondly i tried visualizing a pipe running up the end plate, but the end plate is probably 5mm thick; there's no way air would run through that without stagnating from boundary layer friction and back pressure.
As it is we don't even know how this Mercedes F duct works. It's a funny looking hole with god knows what is happening inside that wing.

I would like to hear F1-eng's opinion on this system. He seemed to have disappeared, but he was a staunch Mercedes supporter and possible team engineer; by the looks of things. :wink:
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ringo
 
Joined: 29 Mar 2009

Post Mon Dec 06, 2010 10:51 pm

I do not want to be nitpicky ,but open loop is a system thatt is reacting to = correcting for outward disturbances ...a system that is governing itself to achieve the desired result for a given input.slowish input signal from an old driver is still an input and will be translated into activating the f-duct..

closed loop is only able to correct for inputs it was programmed for eg it follows the map however complicated this map may be .So if there is a leak in the duct it does not adjust for it,for example.And will possibly not react at all.
marcush.
 
Joined: 9 Mar 2004

Post Mon Dec 06, 2010 11:54 pm

marcush. wrote:I do not want to be nitpicky ,but open loop is a system thatt is reacting to = correcting for outward disturbances ...a system that is governing itself to achieve the desired result for a given input.slowish input signal from an old driver is still an input and will be translated into activating the f-duct..



An open loop system does not react to feedback.

A characteristic of the open-loop controller is that it does not use feedback to determine if its output has achieved the desired goal of the input. This means that the system does not observe the output of the processes that it is controlling. Consequently, a true open-loop system can not engage in machine learning and also cannot correct any errors that it could make. It also may not compensate for disturbances in the system.


http://en.wikipedia.org/wiki/Open-loop_controller
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ringo
 
Joined: 29 Mar 2009

Post Tue Dec 07, 2010 12:27 am

oops .. how could I write it the wrong way around???? please forgive i must be getting old.. :lol:
marcush.
 
Joined: 9 Mar 2004

Post Tue Dec 07, 2010 1:20 am

I figured you made a mistake there as well. :)
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ringo
 
Joined: 29 Mar 2009

Post Wed Jan 12, 2011 8:51 pm

Well guys, I've said it before and I will say it once more.

Mercedes were the only team to run the funky, lower than normal airbox, and similarly they were the only team to both have an F-Duct device and NOT have a sharkfin which connected to to RW. Maybe this has something to do with their device?

I remember seeing MS appearing to momentarily cover a hole at the start of a straight and then do the same toward the end of a straight (I think it was during practice, but I can't remember where) suggesting a flip-flop means of control OR perhaps a little bit of pantomime to throw others off the scent of their "Tuned" F-duct.
The answer to the ultimate question, of life, the Universe and ... Everything?
forty-two
 
Joined: 1 Mar 2010

Post Tue Jan 18, 2011 1:32 pm

forty-two wrote:I remember seeing MS appearing to momentarily cover a hole at the start of a straight and then do the same toward the end of a straight


Adjusting brake balance? The second touch would be to double check before he got to the braking zone.
richard_leeds
 
Joined: 15 Apr 2009
Location: UK

Post Wed Jan 19, 2011 3:24 pm

Nope, he was definitely not adjusting brake balance, his hand was not touching anything, he was wearing a large pad on his left wrist, and this was being momentarily placed against the side of the cockpit. I did have the session on my PVR but the ruddy HDD gave up the ghost a couple of weeks ago!
The answer to the ultimate question, of life, the Universe and ... Everything?
forty-two
 
Joined: 1 Mar 2010

Post Sun Jan 30, 2011 11:29 pm

Nose argument can be laid to rest now since we see the new nose on the W02. The low nose was not the best option. It wasn't the main problem, but it was part of the problem. A poor compromise with weight distribution and aero. The tub was also inherently flawed at the splitter area. We speculated on this last year.

http://www.f1technical.net/forum/viewtopic.php?f=12&t=7904&start=750

for all who suspected it from the beginning, pat yourself on the back. =D>

with posts like these:
To blame the nose is a silly mistake IMO.

For all we know that nose is better than the rest of them and by some considerable margin.

It could be suspension, driver location or loads of things causing the issues.

It's fun to look back. :lol:

adam2007 wrote:
ringo wrote:I think it's the tub, not directly, but because the tub determines how things are packaged longitudinally right?
Obviously the car was made short by moving the driver forward to get room for the tank and trim down the rear body work.
If you look closely you can see shumachers bum teetering over the splitter, driver placement could be the problem for the weight balance and under steer, who knows?
Secondly i don't think that the COG height is one of the major problems. It's not like last year where they had to improvise with the gearbox and Merc engine, so i think the team would be weary of COG height this year and probably go to extra lengths to get it as low as possible.
Visually i think the driver COG is too far ahead, affecting front aero, because the front has to be bulky to accommodate this, and affecting the balance because driver is to far ahead with such a short wheel base.

Image
Merc need to get Shumacher's ass out of that area. :lol: Push it back and put the thy at a steeper angle to cut down the front end bulk. I don't think shifting the weight of the thy upward and having a minute increase in COG because of it will outweigh putting the COG backward for a better balance and the other aero benefits that come with it.
Then again this is all tub design, so i don't know if it can be changed, though increase in wheel base could effectively get some of these things done.


makes me laugh you guys trying to say this is how to fix the problem, leave it to the professionals they spends thousands hours in labs and wind tunnels analzying it all. they know a hell lot more than you, if that easy email mercedes and tell them how to improve the car


Looks like they got the email. :wink:

F1_eng wrote:JohnsonsEvilTwin, why would anyone choose any part with more drag unless it gives a load more downforce?

You honestly don't have any idea what you're on about. A high nose like other teams can be analysed in a few minutes in the wind-tunnel so if it was better, it would have been implemented.
What is people's obsession with the nose design?

Why do you suggest the Merc nose creates more drag?
How about the McLaren front? What about the area under their nose that tries to replicate the effect of the Merc nose?


:lol:

He was right, they did change it. :mrgreen:

This goes to show that F1 engineers are human as well, and should be open to constructive criticism. They don't always make the best decisions. Thanks to f1 technical they made the right changes. 8)

2010 hi nose photoshop:
Image
Image
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ringo
 
Joined: 29 Mar 2009

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