What Does Rear Wing Placement do for Aerodynamics?
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- Опубликовано: 22 апр 2017
- There is lots of discussion on where rear wings should go on cars, lots of people saying put them above the roof, others saying you need twisted profiles below the roof. Allow me to clear that all up.
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Great video!
Idea: Aero analysis of classic F1 cars
This one has been requested a lot, enjoy the video!
Hey Kyle I just wanted to tell you that I really enjoy your videos about aerodynamics. Cheers!
Thanks for the compliments!
Can you please try to do a video like this one for hatchbacks? That would be greatly appreciated. Thanks.
Haha came down here to request the same thing, double down on this.
Yes same here
Same! 😀
Yep, me too !!
Still waiting for this 😂
The British Touring Car Championship (the NGTC cars) are a good example of how different body styles affect wing position. All the cars have a spec wing and to make sure the wing produces the same results, wind tunnel testing is used to determine its place.
Frantically taking notes, as always great info.
Great video as always. The whole of the playlist that you have created can be used as a baseline to design the aero of a vehicle from scratch. Thank you.
Love the aero videos! Keep up the good work.
Speaking of odd rear wing placement, I would love to hear your thoughts on the old Audi TT DTM car. That thing was a mess of aero gubbins all over the car, and a rear wing that hung well past the rear bumper.
Interesting to note that the original test car had the rear wing on the boot lid, then the car moved to a rear set wing with a higher element, then to a lower mounted wing, with the similar rearward mounting.
I think it might make for a fascinating case study on th subject.
Also, touching on vehicle rear window shape, what is the better alternative, to move the rear wing, or add vortex generators to force the air onto the wing? Outside of height regulations because of rules, is there ever a time you would specifically choose one over another?
Love your videos man - as an interested layman whose knowledge comes entirely from watching videos like this, I find your videos are a perfect balance of simple explanation and technical detail. One day when I'm doing my own car for track days, I'll be using so much of this knowledge.
Of course, if I can eventually buy your services I will do so :D
just discovered this channel yesterday night going through your catalog man it's amazing content ❤
Thanks Kyle, very informative
I think that the myth of the wing having to be at about the roof level of the car might come from old NASCAR racecars. In the late 60's, NASCAR wanted to limit the advantages of aerodynamics in cars, so they put a rule that said that you couldn't have a wing that was lower than the boot's height when opened. You can see how they got creative in the automotive industry with the Plymouth Roadrunner, which had a super tall wing.
Excellent video, very clear explanation. I definitely learned a thing or two!
Great! Keep it up!
Greatest video on the subject.
Good! Keep it up!
Could you do a video showing how to make a homemade manometer? and where to attach it and what to look for, in terms of rear spoiler?
Could be a neat project with real world results.
Thanks
Yes! I too would like to see this.
find an airplane graveyard, they should have some pitot tubes to suit your needs, not sure how you would calibrate it though
So NASCAR spoilers, do they just work by using upwash?
What about drag racing spoilers?
Yes thank you for this.
GREAT INFORMATION MAN!!!!!
great video.
Wing Height.....Half of it is for Rear Visibility...plus a slightly higher wing gives you more end plate?station surface...which help with Yaw in a slide/etc.(the rudder effect).
great video! could you do a CFD analysis of the DB11 rear spoiler? I would be very interesting!
Excellent!
very interesting, I've always thought you need the wing up above the roof line like say a Dodge Daytona. I'm putting a wing on my sons project car and thought it would be useless for down force and merely add to the fuel consumption due to extra drag, either way since its a street car I still think this will be the case of more drag than down force benefit and in all honesty I'm only putting one on for aesthetics plus I look at the wings profile and don't see it being very Aero anyway..I use to be into model speed planes so I look at naca designs to judge viability, but thanks for sharing your knowledge with these videos
First 4 minutes of the video confirmed my trunk spoiler and rear canards were positioned perfectly out of shear luck. I was going for 100% looks, but ended up with 100% efficiency.
Just sent it and it worked out lmao.
The black Porshe is my friends Marks car. He had AJ make it for him.. Small world.
So...with a clean air stream over the roofline, a medium height wing will do just fine as long as you are conscientious of the angle attack in relation to downward airflow. If the roofline is too steep and causes flow separation, a high wing position is needed to attain effective use of downforce. A low wing will be largely ineffective and and is basically just a spoiler.
If you put it simply, that is.
need a vid on more info about hatchback wing spoilers! soon! im making a custom one
you should make a video to describe how to take the manometer measurements - i'm sure a lot of people would enjoy it.
Hi Kyle, great videos. Can you please give an explanation on drag type wings that extend the boot line rearward. I am interested in this for a hill climb car where speeds do not exceed 80km/h.
Thanks really helpful :-)
Hey Kyle could you possibly talk about the vortices of the rear wing of an f1 car? It's definetly a beautiful thing and i'd like to learn more about that.
Could you tell us more about tire wake and tire aerodynamics? Like in F1 tires seem to be neglected, even in Formula E tires are covered except for the middle part, is it because of the lift generated by the tires? You see louvers used in Le Mans does it matter if they are horizontal or vertical and what the shape is? Or does only the size matter? And why aren't wheels covered with discs, and why do F1 cars have brake scoops? I hope you can do a video about this, your channel rocks.
It should be interesting a video about brake cooling using aero ducts
Fascinating. Learned something new again. I had never even though about wing-diffuser-interaction. Thanks!
(Then again, I'm more of an airplane guy, so I think all your wings are upside-down anyway ;-) )
thanks for the explanation! could you do a video on how the lotus 88 could get such high downforce using the ground effect?
kyle could you talk about (just a response would be nice too haha) how flow attachment at the boot enhances lift, in case it does, as it is the only conclussion i could come across trying to figure out why vortex generators arent commonly used.
Could you possibly go into detail on how matter with a different body type such as estate cars or hatchbacks? Having such a steep almost cliff like rear must be dramatically different compared to the saloons displayed in the video.
Hey, nice video, i m interested in drag type wings, or extended boots / rear decks, from this video, i get idea that its just to maximize diffusor effects and streamline the airflow? have you had any experiments with them?
Please analyze Red Bull X2011 and/or X2014.
How about cleaning the airflow between wing and the boot - making it more flow attached at the boot with vortex generators at the back of the roofline, and also bottom of the wing?
Unlocked new mastery: Aerodynamics Expert
Progress of Mastery: 0.05%
I can confidently say im an expert now.
So on a hatch back, where would the best location be in your eyes? Since the back of the car is very flat, I would assume there would be a bunch of turbulent air without any wing or diffuser. If you wanted to aid the diffuser, would it be wise for the rear wing to sit slightly higher than the large, flat roof line of a hatchback vehicle in order to get air to flow under the wing? or are you better off mounting closer to even with the roof line and running more angle of attack?
Have you ever done an analysis of the VL Walkinshaw Commodore?
Hey Kyle, Quick question. what happens to the flow off the roof of the car when u add a vortex generator? does it essentially straighten it out?
Also what happens when you use a dual element wing? does it just essentially allow you to gain more downforce with less angle of attack?
Thanks.
What does the small lip on the rear windscreen do for aerodynamics? is it just to look cool or is there a real benefit to it?
I've always wondered why wings were placed so far rearward. It seems to me that the extra rear downforce you get from leverage comes totally at the expense of lift at the front. Seeing as front downforce is often harder to come by, especially in a street car with real-world ground clearance (not a GT3RS), this seems counterproductive. It seems like the ideal rear wing location should be directly over the rear axle, which would not cannibalize from the front at all. I know that I must be wrong, because all the smartest people in the world stopped putting wings there about 5 minutes after car wings were invented. But I haven't seen a great explanation of WHY that's wrong. The diffuser thing is interesting, but my intuition is it doesn't affect a street / track day car that has no real diffuser or underbody tuning.
HI Kyle thank,s very helpful. I am trying to understand what is happening to the air behind and Inside my car, I have a rear spoiler and an Opening Sun roof and feel that it causing Exhaust Fumes inside the car ? Any ideas please. ?
More road car videos
In the first scenario, can you explain how the low pressure regions from the rear wing and boot cancel each other out if they are both low. However, when a boot spoiler is added (2nd scenerio), its high pressure region cancels out the low one from the rear wing. Thus, I am confused when you say that low p regions cancel each other out as well as high vs low.
So, the Chaparral 2F's high mounted rear wing was for aerodynamic efficiency? So it can reach a more clean stream of air?
How do the flat drag racing rear wings work?
Good video,, if I get a eBay 50 Dollar rear wing , where should I mount it in my 1974 Datsun Z car to get good down force from 100 to 150 mph? And how could I measure how much down force I am getting? Thanks, I will look at your other video for answers also.
Kyle, I would love to hear a more in-depth analysis of wing endplates, especially the complex variety found on modern F1 cars. Thanks for the great automotive engineering commentary!
How about a top down convertible? Would you just try to get the highest wing to avoid dirty air?
What about the 'ducktail' spoilers that the current NASCAR cars have?
Where you place the wings on a hatchback car? Or is it better to make a roof extension?
Why because it looks cool
About how many degrees is a roofline to boot lid considered too steep? And how does a convertible top compare in this scenario?
i think i recall a video mentioning a sudden change any more then just 7 degress can cause separation? a nice smooth radius like on the toyota prius i would suspect the air stays attached the full length of the roof and boot contour. just some information to try and provide some resolution to your questions, i may be incorrect.
Did I hear you right Kyle? Are you saying that low pressure lift provides more lift than the high pressure on the top? That could only be true if you have a low drag setup - surely? A wing profile simply makes a wing efficient - just as with a plane - you can easily have a plane with flat wings, if just makes them fly not so great, and waste fuel.
On a plane, at least, the vast majority of lift is obtained by directing a very large mass of air downwards, because the back of the wing is lower than the leading edge by some margin, when the plane is in level flight. Engine power is used to deflect air downwards to maintain the vehicle's flight.
So, the reverse must be true for cars: If you want lots of downforce, you direct a large mass of air upwards, while reducing drag and maximising lift. You achieve that by having spoilers with upside down wing profiles - yeah?
So, unless you are only interested in high speeds, you've got to have your rear wing with the tail significantly higher than the leading edge. Otherwise you are only going to generate aerodynamic lift, not mass-directed lift, and that is very small - surely? I can't see any non-silly wing in a minimal drag situation making more than 30 or 40 kilos of downforce - SURELY?
If you want hundreds of kilos of downforce, you need to direct hundreds of kilos of air upwards at a vast rate of knots. Or have I got that wrong?
A little late clearly, but a wing creates lift via creating a pressure differential between the top and bottom of the wing surface. For a standard race car wing, which produces negative lift, the air particles accelerate around the bottom curved surface, but since there is a constant mass flow, Bernoulli's Principle says the high velocity section must have a lower pressure because otherwise that would defy mass and energy conservation. The converse effect happens on the top side of the wing, where it decelerates and builds pressure. The low pressure side of the wing is effectively a vacuum at this point, and the air from the top side wants to occupy this vacuum, pulling the fixed wing down.
What you're talking about is the Newtonian contribution to aerodynamic lift, which is the top side of our wing elements apply an upwards force on the air when it collides, deflects, and accelerates upwards with the regions of high camber or high angle of attack. In addition to downforce creation, this dynamic leads to form-induced drag. (the force vector is not straight up, it faces normal to the wing surface, which is facing forwards) Newton's third states that this force has an equal and opposite reaction from the air to the wing elements, where the air is pushing down on the element.
Also, the flow has a centripetal acceleration around the curvature of the wing (lift generating wing), thus also a centripetal force pulling the flow inwards towards the wing surface. The curvature increases the closer you get to the wing surface, and so the centripetal force increases closer to the wing surface. Thus, there is a larger reacting force of the wing on the fluid pointed upwards, opposite the centripetal force acting on the fluid, ie. exerting an upwards force on the wing. The higher centripetal acceleration yields a higher angular velocity and thus a greater total velocity vector on top of the wing, ie. lower pressure on top.
Does this apply to hatchbacks as well
Thank you , I would buy a course made by you if you take us through the basics of Aerodynamics .
Interesting, what in particular are you interested in? If you want one-on-one time you can shoot me an email at kyle@jkfaero.com and we can have a consulting session? I have a feeling that might be out of the budget though...
Actually I am not working on a project right now . I am a mechanical engineer looking to be specialize in cars in every aspect including cars aerodynamics . Your videos have been an astounding help however I sometimes feel that I am not competent enough to fully understand as I don't have a strong foundation about the basics ,that's why I suggested that you make videos that are for noobies, and I assure you that many people will buy them even if they are not free on RUclips .
do roof spoilers affect downforce?
Kyle, I drive a convertible car. Would there be any benefit to running a rear wing considering all of the airflow is likely detached at that point?
iamtehstig I'm curious about this as well. some of the old Viper ACR convertibles, had a $1800 spoiler they sold and I'm trying to figure out if it even had any effect, same goes for the Battleaero new edge mustang.
But when you have the rear wing to up from the chassis of the car you have the problem with the drag effect that pulls more back the car as higher the rear wing is. Or the roof of the car makes the air flow to loose this property when flowing above the floor of the car? because if not it is not good for performance to raise the level of the rear wing to obtain more nice airflow. No?
Have you moved a rear wing forward to increase downforce? If so, how much...what type of car?
So that's the reason why fromt splitter works better when it's closer to the road
As the wing is closer to the rear of the car - not optimal - the splitter when it's closer to he ground works better ?
Am i right??
Where is best to place a wing on a hatchback car?
In clean air
I'm a little confused. You say that moving the rear wing forward is more efficient. But you also say that moving the wing back produces too much downforce. As a wing is meant to produce downforce, I would think that moving it back is more efficient? (and to compensate for the front end grip, you would either need a less aggressive rear wing, or better front aero)
Allow me to clarify; Moving the wing forwards means we can theoretically make more downforce from the wing for the same level of aero balance, but we have issues with the interaction with the car (which lowers wing effectiveness). Moving the wing rearwards makes the wing more effective (in terms of interaction with the car), but it can't provide as much downforce or otherwise the aero balance will shift rearwards, make sense?
Moving the spoiler too far back or too far up creates a larger Moment arm which acts on the car. The closer the wing is to the CG the more the downforce will be spread evenly throughout front and rear axles. the further away you move it, the more force is being directed JUST to the rear wheels which can produced lift/understeer in the front of the car sometimes.
How about a video about Wing profiles for street use?
Or...maybe about REYNOLDS #s and wings profiles that are good in the 400k
The Clark Y Profile was what they used on the 1969 Dodge Daytona.
For the guys, interested in Wings/aero-foils. A link with ALOT of info on profiles/shapes.
airfoiltools.com/index
MSHD or S1223. -Friendly neighborhood FSAE aerodynamics member
Can we get F1 version of this?
It's ALL BANNANA'S...LOL :-)
please do an analysis of the new iranian fighter jet qaher 313
So porsche listened to this for GT3 and GT4 RS 😂
In one of your earlier videos on rear wings on road cars you mentioned that they really have little real effect. I had a Mazda Protoge that always felt unstable on the highway with a tail wind. 100 KPH forward plus a 30 KPH head wind (130 observed ) VS 100 KPH forward plus 30 KPH tail wind ( 70 KPH observed ). I never put a wing on, but an extra 50 or 60 pounds on the rear might have made a difference.
@Kyle What wing profile is typically used for rear wings?
Looooootsssss of different ones, ranging from Benzing to highly cambered NACA profiles to Selig and others. All the best ones are custom though.
lets not forget TRD weird thing the did with the Aurion. boot lip + spoiler because reasons.
i will one day get around to fixing everything they screwed up or halfassed on that car...
Watch kyle draw a hamburger.
I'm considering a wing for my 350z I want it swan neck mounted, but I was considering having kind of the LMP style shark fin mount. It would be connected to the front of the roll cage through the roof and the back of the roll cage through the roof, there would be pins in the rear and a hinge on the front to allow the hatch to be opened, but I'm worried about the catalievering effect it could have.
I UNDER STAND EVERYTHING NOW
drift cars: WING MOVED TO THE BACK AND HIGH
TOP FUEL CARS: VERY HIGH WING
any ither racing car: forward wing