Brought the car up around close to the school for storage while the rest of the wing is being built..
Again, keep in mind that the shape for the end plates has not been cut yet. They won't be rectangles. Also, there is packing tape over the end plates to protect them from getting scratched.
You can dance, you can jive, having the time of your life See that girl, watch that scene, dig in the dancing wing
Friday night and the lights are low Looking out for the place to go Where they play the right music, getting in the swing You come in to look for a king Anybody could be that guy Night is young and the music’s high With a bit of rock music, everything is fine You’re in the mood for a dance And when you get the chance...
You are the dancing wing, young and sweet, only seventeen Dancing wing, feel the beat from the tambourine You can dance, you can jive, having the time of your life See that girl, watch that scene, dig in the dancing wing
You’re a teaser, you turn ’em on Leave them burning and then you’re gone Looking out for another, anyone will do You’re in the mood for a dance And when you get the chance...
You are the dancing wing, young and sweet, only seventeen Dancing wing, feel the beat from the tambourine You can dance, you can jive, having the time of your life See that girl, watch that scene, dig in the dancing wing
Wow, if you could program that thing for braking and hard turns, simply by having sensors detect the touch of the brakes and the position of the steering rack... That would be sweet... You probably have something better planned though lol
Not exactly how it will be done, but you're on the right track Jesse. It will be fully automatic/dynamic while driving. (Optimizing the position of the airfoils as you drive)
Proportional braking/wing positioning Auto adjust for speed If your Fiero had antilock brakes you could use the wheel speed sensors to determine rear wheelslip and adjust downforce appropriately.
I haven't read the thread from beginning to end, so you'll have to excuse me if you've already discussed this, but have you figured out the amount of down-force generated for a given speed with your airfoil at different angles of attack?
I didn't really get into it within this build thread but yes we have a full report with everything documented included the CFD data which gives us downforce at different speeds and angles of attack.
That data (and the pressure distribution) was how we optimized the placement of the actuators leverage on the airfoil, such that they can move the wings at high speeds (high downforce).
As well as a pictures of the decklid cleaned up and spray painted, and the final assembley:
In the corner of the picture, you can see a logitech steering wheel and pedals. We have interfaced them with the wing for presentation purposes (school project). Won't have anything to do with these while its on the car.
Is it just me, or does your wing sound like a dot matrix printer?
Digging where this is going dude, keep the updates coming. It's going to be sweet to see it on the car with a nice rear window camera view of the wing in action.
I didn't really get into it within this build thread but yes we have a full report with everything documented included the CFD data which gives us downforce at different speeds and angles of attack.
There may not be as many of us interested in the physics behind the design as there are in the cosmetics of it, but I'm sure you'd find an expanded audience if you were to explain how and why this will work to your advantage on the track. I'm interested.
Fair enough. One of the reasons I haven't posted more of the physics etc, is that this is a school project. We have been so busy working on the reports and descriptions that time is an issue (and fatigue lol). For the past few weeks we have been working day and night to get it ready for a competition.
However, I'll dive into the physics a bit.
Basically, it is somewhat common knowledge that a rear wing helps produce a downforce in the rear of the vehicle, thereby increasing the load on the rear tires. By increasing the normal force on the tires, the friction force that can be generated by them is now greater. This translates to greater cornering capabilities, and high speed stability.
To take this a step further, we figured that adjustibility would be a nice feature. The 2-D airfoil selected was based on CFD analysis of many profiles. We were mainly looking for something that could produce a lot of downforce at lower speeds and wouldn't be sensitive to stall (due to the turbulent nature of air around a vehicle). This matters when it comes to adjustibility because we had to figure out the stall angle of the wing profile, and then design a mechanical system that would allow it to rotate while in use.
To make things even more complicated (but somewhat innovative), we chose to make it active. This has a multitude of benefits on the track, but does increase the complexity of the project. The benefits are mainly in optimization of force under different circumstances. On a track, you have many different scenarios (long straights, hard braking, high acceleration, high lateral acceleration). Each of these scenarios requires different amounts of downforce and drag from the wing. Therefore, a passive wing in one position (even if its adjustible) must be set once and cannot adapt to the different needs of the vehicle. An active wing can make high downforce at the expense of higher drag during turns or braking, but it can also switch to lower downforce positions and low drag for the long straights. This reduces the amount of power needed to push something like this through the air, and the extra power can be available to achieve higher top speeds. The higher downforce in corners and braking allow for higher speeds in the corners, and decreased braking distances (can go further into the braking zone).
Lastly, the split wing was to top it all off. The main benefits of having independent halves of the wing are in reducing body roll. Body roll occurs during hard cornering (which can be experienced at the track). When the vehicle body rolls, weight is transferred to the outside tires, while the inside tires lose a certain amount of normal force. While some weight transfer is necessary, an excess amount can be detrimental to cornering speeds and stability. Therefore, by splitting the rear wing, the half that is on the inside of the turn can be moved to a higher angle to produce more downforce. This uneven distribution of downforce creates a counter moment around the roll center of the vehicle and restores some of the normal force on the inside tires. This may decrease a bit of body roll, while increasing the friction force on the inside tires, resulting in higher cornering speeds.
Thats pretty much the theory behind it. One of the biggest issues is actuation time however. Obviously these events that I just mentioned (corners, braking, etc) come and go very quickly on the track. The wing has to respond quickly to be effective. We have some expensive motors and equipment that can handle the speeds necessary to be an effective addition to a vehicle. From our zero angle, to our stall angle, we can actuate the wings in half a second (up to 200km/h). Beyond that, it slows down a bit, but that issue can be fixed with more money (ie. better motors). We were constrained to a certain budget.
Hopefully that gives a better picture of whats happening in terms of the theory behind it. I can get into it a bit more at a later date. In the meantime, theres a 30 page report that has to be written up thats due tomorrow!
Ask more questions if something is unclear or doesn't make sense! Criticism and suggestions are both important to the prototype and how we go about designing things!
[This message has been edited by doublec4 (edited 03-24-2011).]
this is really a great project , just like all the other neat things you have done to your car .it will be interesting to see how it will work at a track .but , i am pretty sure that every sanctioning body for the various types of racing has banned active aero devices .maybe it would be allowed for autocross ?
Excellent description of what's going on (almost sounds like the introduction to your report!). I'd love to see a sampling of the rough magnitude of the expected forces generated for a couple typical track speeds and angles of attack (AoA) (when you have time).
Wish I would've had interesting thesis topics to choose from when I went to school!
Thanks again guys, glad to see its getting some views We've put a ton of hours into it.
wftb, active aero is banned by most sanctioned bodies. However, this is more of a personal endeavour / doing it because we can and we're interested in it. Plus, if nobody developes the technology, then it will never make its way into any racing league. Regardless, it would just be fun to run on lapping days and have people looking at it funny.
Bloozberry, we're going to try and get some force data out of it somehow. It will be a little while longer though. Still have to get the actual program code worked out for the vehicle. Its coming along.
In other news, today we participated in a competition against other groups within the university. It was focusing on contributions to the industry with the projects, and industry/partner relations. We placed 1st and we're quite proud. We now have the chance to move on to compete at the provincial level. We just have to be in the top 5 spots province wide. Hopefully it pans out! It would be great exposure.
Here are some pics from the event:
Another video coming up soon, just strictly the wing working at a slow speed using the game controller inputs. (For presentation purposes)
Awesome build. I just read this entire thread, looked at all the pictures, and hot damn I love the work you've done to your Fiero. Like so many other people, I will be considering a black/silver interior do-over, though my exterior will remain black. The side scoops and the diffuser look awesome, as does the "street" spoiler. And the one y'all just did for the school project thing, awesome, great work.People dream of your car... and my car dreams of a motor. Haha. Good luck with any future projects.
Excellent work! Congrats on the First Place. I've enjoyed following your progress while lurking but have to ask; with respects to the dynamic nature of the spoiler, had you considered a flexible actuation as opposed to the split rigid design? Off the top of my head, if it were to have a fixed leading edge, flexible urethane airfoil, and a movable trailing edge perhaps with a central pivoting point? Just picking your brain.
Thanks FieroAK, those are some nice compliments. Its been a lot of work, but definitely fun to drive
ReallyBig, thats a pretty cool idea, just a lot harder to implement. It would be even more innovative and "new" but a little beyond my aerodynamic knowledge at this point. We purposely stuck to a constant 2-D profile rather than creating a variable profile because it is a lot easier (relatively) to understand the behaviour of air flow around an airfoil that only changes angle of attack. Changing the profile would totally change the airfoil's properties and would be really impressive! I love the idea though... I'd have to do a lot more research into aerodynamics and airfoil design. Might be possible as a personal endeavour when I don't have the time deadlines imposed by it being a school project.
Did you see this morning's F1 race? They are using a newly regulated DRS (drag reduction system) in which the upper portion of the rear spoiler is opened by the driver at speed to create a "hole" in the spoiler for a claimed equivalent 100 horsepower advantage on the straight stretches. During the race the DRS was increasing speed at the end of the straights by 12 KPH. Your wing could obviously be feathered to do the same thing.
Sorry I missed this last Friday, I was on campus Friday I wished I stopped by to take a peak at your project. looks like you were in the west UA atrium too.
Awesome project BTW.
------------------ 1986 Pontiac Fiero SE 3.4L | The Fiero Blog (Since April 2000) ----------------------------------------------------------- My Portfolio site | JustinChristie.ca
You know where I stand on this wonderful build. And good luck with the competition. After reading your descriptive answers to the questions presented, you guys will do just fine. In the competition, and life. Bravo!
Justin, we will be displaying it again sometime in early April. Probably the 7th or 8th in the same area, and hopefully with it fully installed on the car. If you have a chance to come by then, feel free!
Tony, thanks for the good luck wishes. Just have to wait to hear back to see if we placed in the top 5 in the province. Keeping our fingers crossed.
Am I the only one wondering if we will see this wing on your Fiero this summer? I read the "track day" comments but I'm curious to see how it would look. We'll probably have to settle for photoshop's for now
As a huge F1 fan that's being reading up on DRS for months this was a timely project - great work.
You'll probably see the wing on the odd time in the summer, maybe at a show or something. Gotta show off the hard work
I should be installing it this coming week however. We have more presentations to do and want to get some video footage of it working while I drive. So you won't just have to settle for photoshop!
Shill, I remember seeing that video a couple of weeks back maybe. Cool wing, I believe its an ice racing car? The guy is on the forum here. If I remember correctly, its hydraulic powered but is not "active" in the sense that it automatically changes angle as you drive. He has buttons for it I think. I could be wrong... either way its pretty cool.
Excuse the filthy car. Its that time of the year around here where the roads are really dirty and it has been raining lately.
The wing definitely looks like a track wing. We took it for a spin without the electronics hooked up and we got some weird looks from people. No big deal
Then we hooked up the electronics, blew a fuse... oops! Finally, the skies decided to open up and that ended our day. Never did get to see it work on the car today. Maybe tomorrow!
We did a little trouble shooting, replaced our fuse and went for a test drive.
Took a quick video showing the split action on the car:
I have more video I have to sort through. On the rough roads around here the wing is somewhat sensitive to pot holes. We have to play around with the coding a bit more to filter those out. On the track it would work a lot smoother without the pot holes. More video to come. Hopefully with the car washed too!
Wow, all I have to say is Wow! Great build, great car! It will be very interesting to see how that wing reacts and changes the dynamics of the car on the track.
It definitely looks huge on the car, did not realize how big it was from the build pictures.
Bravo!
