When I design our new car?I want to fixed my rear wings on the suspension?But I can‘t give myself a reasonable proof that this kind is better than fixed on rearbox. If someone can give me an advice about it?
THX
Danny
xiemingze@gmail.com
When I design our new car?I want to fixed my rear wings on the suspension?But I can‘t give myself a reasonable proof that this kind is better than fixed on rearbox. If someone can give me an advice about it?
THX
Danny
xiemingze@gmail.com
If you don't know why it should be better why do you want to do it? Think about what the differences between the two concepts are. What are the advantages and disadvantages of attaching the wing to the suspension?
And if you choose to do this, make sure you don't use your rear wing as an incredibly stiff anti roll bar...
Rennteam Uni Stuttgart
2008: Seat and Bodywork
2009: Team captain
GreenTeam Uni Stuttgart
2010: Seat and Bodywork / Lamination whore
Formula Student Austria
2012: Operative Team
Try to sketch a "force path" from wing to tyres in each of two cases.
Lorenzo Pessa
D-Team UniPisa (alumni of E-Team - Università di Pisa)
FSG & FSAE-I 2009-2010
Im assuming that you are comparing unsprung aero vs sprung aero. The question that I would have is how much downforce are you making? Would it require such stiff springs that would compromise other aspects of the car? If that is the case maybe you need to think about wings atttached to the a-arms.
Callen Schmalz
SDSM&T Formula SAE
Drivetrain/Corners Lead - 2012-2014
I think the case of unsprung vs sprung aero is far more critical in the case of under trays and ground effect devices than it is with wings.
With a sprung undertray/front wing you are moving towards and away from the ground, so your static position needs to be higher up so that you do not stall when things approach the ground. In doing this you compromise on the maximum downforce you can get at normal ride height. Other complications from one side of the undertray/front wing being lower/higher than the other are also a concern.
With fully unsprung undetray/front wing in ground effect yuo can put them as low as you want for maximum aero (minus a few mm for tyre deflection maybe) without worrying about the above problems of ground proximity causing stalling/imbalance. The difficulty with th is is mounting everything to you're uprights and maintaining stiffness in your aero devices, good packacking, etc.
With wings you are merely talking about loads path to the wheels and having more stable loads on the tires, yes this is also important but imho probably less so for aero loads.
In short if you have the time and resources to do it properly, then the pros of unsprung ground effect aero definitely outweigh the cons. With rear wings less so, but if you can think of a way to do it easily and without compromising any other systems or vehicle reliability then it is probably marginally better. More often than not however, it is likely that you could better use your time and resources developing another area of the car first.
Dunk
--------------------------------------------------------
Brunel Racing
2010-11 - Drivetrain Development Engineer
2011-12 - Consultant and Long Distance Dogsbody
2012-13 - Chassis, Bodywork & Aerodynamics manager
2014-present - Engineer at Jaguar Land Rover
It seams your last sentence give me some inspiration?I will compare these two kinds?thank you ?Originally posted by Bemo:
If you don't know why it should be better why do you want to do it? Think about what the differences between the two concepts are. What are the advantages and disadvantages of attaching the wing to the suspension?
And if you choose to do this, make sure you don't use your rear wing as an incredibly stiff anti roll bar...
OK?I will try this way
Originally posted by Lorenzo Pessa:
Try to sketch a "force path" from wing to tyres in each of two cases.
In the plan?the rear wing will provide 2000N downforce at 80km/h ,sounds a little big.So I will think about other factors,thank you for reply!Originally posted by cal_len1:
Im assuming that you are comparing unsprung aero vs sprung aero. The question that I would have is how much downforce are you making? Would it require such stiff springs that would compromise other aspects of the car? If that is the case maybe you need to think about wings atttached to the a-arms.
Wow?Such a big reply.after reading it,I got a lot of information,But "this is also important but imho probably less so for aero loads",perhaps my english is so poor,Im confused,can you explain more about it? Next I will carefully analysis the load's effect on our suspension,thank you a lot!!!Originally posted by Dunk Mckay:
I think the case of unsprung vs sprung aero is far more critical in the case of under trays and ground effect devices than it is with wings.
With a sprung undertray/front wing you are moving towards and away from the ground, so your static position needs to be higher up so that you do not stall when things approach the ground. In doing this you compromise on the maximum downforce you can get at normal ride height. Other complications from one side of the undertray/front wing being lower/higher than the other are also a concern.
With fully unsprung undetray/front wing in ground effect yuo can put them as low as you want for maximum aero (minus a few mm for tyre deflection maybe) without worrying about the above problems of ground proximity causing stalling/imbalance. The difficulty with th is is mounting everything to you're uprights and maintaining stiffness in your aero devices, good packacking, etc.
With wings you are merely talking about loads path to the wheels and having more stable loads on the tires, yes this is also important but imho probably less so for aero loads.
In short if you have the time and resources to do it properly, then the pros of unsprung ground effect aero definitely outweigh the cons. With rear wings less so, but if you can think of a way to do it easily and without compromising any other systems or vehicle reliability then it is probably marginally better. More often than not however, it is likely that you could better use your time and resources developing another area of the car first.
Holy downforce Batman!!!Originally posted by old soldier:
...the rear wing will provide 2000N downforce at 80km/h...
If you can design a rear wing to pull that much downforce at that speed, what the heck are you still doing in school and why the heck aren't you working for Adrian Newey?
Seriously, set some more realistic aero goals. And if you really do insist on unsprung aero devices, after doing every analysis previously mentioned, do some research on the University of Maryland and South Dakota School of Mines and Tech. They have both ran unsprung aero within the past year.
San Jose State University
FSAE Chassis and Ergonomics Lead '12-'13
FSAE Chief Engineer '11-'12
FSAE Chassis Technical Lead '10-'11
Formula Hybrid Chassis Grunt '09-'10
"A designer knows he has achieved perfection not when there is nothing le