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Thread: New Aero Packages for 2011 Rules

  1. #11
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    Originally posted by Scott Wordley:
    To give you an idea of what we are thinking, at least for the front wing here are some photos from a test we did recently.

    We wanted to find out how big the front wing could be before obscured the vision for a short driver (like Luke!). We also wanted to check if the extra forward length made any difference to the driving line, and if we would simply hit a lot of cones with that outside corner. The results were pretty interesting...







    Im not seeing any pictures?

  2. #12
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    DStevens:

    We are currently using ANSYS CFX and like it a lot. We also have access to Star CCM+ and are looking into it. I know a lot of US aero teams use it.

    RANeff:

    Sorry will try again to get them working properly.


    Thrainer;

    Please see below, that should qualify.
    Also rotating cylinders is not such a crazy idea... we have looked at it.


    Aerodynamics for Formula SAE: Initial Design and Performance Prediction

    Date Published: 2006-04-03
    Paper Number: 2006-01-0806
    DOI: 10.4271/2006-01-0806

    Author(s):

    Scott Wordley - Monash Univ.
    Jeff Saunders - Monash Univ.

    Abstract

    The initial design of an aerodynamics package for a Formula SAE car is described. A review of Formula SAE rules relating to aerodynamics is used to develop realistic parameters for the specification of front and rear inverted airfoils, or ‘wings’. This wing package is designed to produce maximum downforce within the stated acceptable limits of increased drag and reduced top speed. The net effect of these wings on a Formula SAE car's performance in the Dynamic Events is then predicted. A companion paper [ 1 ] describes in detail, the CFD, wind tunnel and on-track testing and development of this aerodynamics package.



    Aerodynamics for Formula SAE: A Numerical, Wind Tunnel and On-Track Study

    Date Published: 2006-04-03
    Paper Number: 2006-01-0808
    DOI: 10.4271/2006-01-0808

    Author(s):

    Scott Wordley - Monash Univ.
    Jeff Saunders - Monash Univ.

    Abstract

    The detail design and development of a high downforce aerodynamics package for a Formula SAE car is described. Numerical methods are first used to develop multi-element wing profiles which conform to FSAE rules while still generating high negative lift coefficients. A range of full scale wind tunnel testing data is presented for these designs, demonstrating their performance, both in isolation (free-stream), and on the car. Three different techniques are also developed for measuring the performance of a front wing in ground effect.


    Aerodynamics for Formula SAE: On-Track Performance Evaluation

    Date Published: 2007-04-16
    Paper Number: 2007-01-0897
    DOI: 10.4271/2007-01-0897

    Author(s):

    Scott Wordley - Monash Univ.
    Jessie Pettigrew - Monash Univ.
    Jeff Saunders - Monash Univ.

    Abstract

    The measured on-track performance of a Formula SAE car with a high downforce aerodynamics package is presented. Data logged from variety of different driving tests is used to determine how the addition of ‘wings’ affects the car's acceleration, cornering, braking and slaloming abilities. These results are then compared with analytical predictions for the same car, presented in earlier papers [ 1 , 2 ].
    Regards,

    Scott Wordley


    Scoring in every event for the last 12 comps running!
    http://www.monashmotorsport.com/

  3. #13
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    Scott,

    The new rules for aero are certainly very interesting. Even with the old rules, high levels of aero appeared to offer points according to the lap time simulations I had developed. However the difficult questions were the effect of potentially more cones hit due to the increased plan view of the car, the required resources to make an effective aero package work, and the potential reduction of mechanical grip due to weight of aero on unsprung or stiffer springs/dampers if sprung. Some of this is diffcult to assess without actually building a set and going running.

    Any team not re-evaluating their concepts to the new rules is making a bad move, it is a major change to the aerodynamic potential of these vehicles. However this would be true of any major rule change such as the shift from 50 to 100 points for fuel economy.

    The more worrying trend to me is seeing the development potential in the aero packages of the teams that are running them. It is as if Carroll Smith's predictions of 10 years ago are beginning to come true. I am sure that Monash are aware of many improvements that they could make to their car to improve mechanical grip and base chassis performance. This is despite the speed they have shown in all dynamic events. I am kept up worrying some nights of the team that will match UWA/Stuttgart style mechanical grip with a Monash aero package. (Please do not interpret this as insulting the quality of car that Monash make to carry the wings, it is not. Even without wings they would place very well)


    Thrainer,

    As Scott has posted, he has shared quite a lot of information with other teams on the topic of aero, including papers and quite a lot of posts on these forums. Monash have also shared sets of wings with other teams to do testing with them.

    Kev

  4. #14
    Originally posted by DStevens:

    I would be interested in how the Aurburn team analysed their tunnels, and how effective they are.


    Aurburn Response:
    Man I tell you what I stuck a diffuser in the bed of my buddy's pickup truck and drove it down the interstate bout 100 milnhour it didn't fly away so figgered it was pretty good

    Good 'ol Boys
    WAR DAMN EAGLE MOTORSPORTS
    eeeerrrdienamics

    Auburn Response:
    I did 3D CFD iterations using Ansys CFX -> http://www.youtube.com/watch?v=HWK0IDqtGFM

    As to how effective they are, We will be looking to validate these results this week or the next through real world testing. I'm still skeptical about accuracy the predicted values from Ansys.

    I'm very eager to see how other teams have use the new regs, and I posted the above video hoping to get some feedback. This is our first year doing aero so I'm trying to learn as much as possible. Thanks.
    Kurt W.
    War Eagle Motorsports
    Aerodynamics

  5. #15
    Wings also make the car noticeably easier to drive, though it's hard to isolate that aspect and measure its affect.

    Also, I had a conversation with a rules committee member about the new aero rules, and he thought it was odd that a lot of teams were expanding their aero packages to the maximum without being able to justify it. don't assume that the maximum of the rules is the best place to be. I saw a lot of rear wings in previous comps where i was skeptical that the overall system was balanced. I'm sure that will be an issue for some teams with the new rules.
    Matt Brown

  6. #16
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    Originally posted by Scott Wordley:
    Lorenzo, I disagree.
    In our experience the actual (perceived?) cost of the car does not correlate strongly with the points a team scores for that portion of the cost event. Have a look over the results from any competition and you will see this is the case.

    In terms of a competition point sim we find it is easiest to assume every car scores full points for all static events. That way you get an indication of the maximum point scoring potential of the car.

    That's a subject for a whole different topic though, i will start it tomorrow. Let's talk aero here.
    I was waiting the new topic, I beg your pardon if I reply here.

    The 100 cost points are partitioned between cost of the car (40 pts), accuracy&...&visual inspection (40 pts), real case (20 pts).

    Aero package influences directly only the cost of the car.
    Taking data from the last FSAE-Italy I add the cost of aero packages to the cost of my team car (ET3).

    I have done a rough estimate of the costs (conservative! so the resulting costs are less than real, I hope).

    wings: 1600$
    undertray: 900$

    [Is someone laughing now? :-) ]

    the cost of the car points are
    ET3 : 16.064 pts
    ET3+wings: 12.112 pts
    ET3+underbody: 13.739 pts
    ET3+wings+undertray: 10.187 pts

    There is a difference from 4 to 6 points.

    Aero doesn't affect other static events.
    Lorenzo Pessa

    D-Team UniPisa (alumni of E-Team - Università di Pisa)
    FSG & FSAE-I 2009-2010

  7. #17
    Lorenzo,
    Remember that the total points score is 1000 points. So the cost difference makes up roughly 0.5% of a team's score.

    That being said, I'm not 100% with Scott on this one either. I see the point of "eliminating" the static events from the event simulation when you're trying to decide "do we do wings or not?". But I think you have to keep in mind that you better be prepared for the static events when you get there - it's a lot easier to lose points in design than gain them because you overestimated your skills and resources.

    This is all part of the game though, and topics like this could probably dominate the forum if we all stated our opinions.


    To return back to Scott's original post, I too am very eager to see what the rules produce for winged wonders this year. Aero was a hobby of mine (I'm a Mechanical Engineer) and our team never had enough people working together to justify trying an aero package. I've moved on from University, and I intend to keep up-to-date with the FSAE community.

    So: Pics or it doesn't exist.
    Mississippi State Motorsports 2003-2010
    Everything but the kitchen sink

    ISMANS
    iMaster 2011
    Conception Auto Advancee par la Competition

  8. #18
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    Originally posted by Superfast Matt
    (rules committee member)... thought it was odd that a lot of teams were expanding their aero packages to the maximum without being able to justify it.
    Could you make a lighter wing, mounted lower, further back in the car, with a higher l/d ratio? You would get the same Cp with lower weight, lower drag, and lower CG location.

    I don't know enough about aero to answer that question.
    Portland State - 2009-11
    Desire is the key to motivation, but it's determination and commitment to an unrelenting pursuit of your goal - a commitment to excellence - that will enable you to attain the success you seek. - Mario Andret

  9. #19
    sbrenaman,
    Generally speaking, the lower the rear wing the worse it operates (Lower downforce and lower drag, but at a lower L/D), however if you run an undertray you could get a boost from the rear wing pumping the diffuser. The front wing and body work suck a lot of the energy out of the nearby flow, so getting the rear wing out've there can increase your downforce quite a bit.

    One of the studies we did a could of years ago showed up to 50% loss of downforce (relative to freestream) at some of the lower heights we tested in the Wind Tunnel. There is some graphs in Scott's 2nd SAE paper on FSAE Aerodynamics.

    The compromise you need to make is the total downforce level/drag moment arm(due to RW height)/and CG height. CG height only really becomes an issue with passing tilt/rolling on track due to side gusts than any load sensitivity effects.
    Monash Motorsport
    Aerodynamics/Vehicle Dynamics/Management
    07-?

  10. #20
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    Scott,

    You could do that.

    We have found FSAE rear wings to be particularly sensitive to height, and less so to for/aft location.

    So you could go smaller, or less aggressive, lighter and higher and generate a similar downforce and potentially less drag. However your contribution to CG Height generally gets bigger, and your rear balance increases due to the higher drag component having a greater lever arm which needs to be reacted by more front wing (generally your limiting factor).

    The more important question is: Are you sure you want the same levels of downforce, just more efficiently?

    I doubt that most aero teams were content with the old package space, and so will be more than happy to exploit the extra available in the 2011 rules. Whether this will be enough to satisfy them remains to be seen...

    My gut feeling is that the high powered 4 cylinder cars will fill every last inch with high lift multi-element wings and diffusers, much like the current state of affairs.

    It will be interesting to see how the singles and twins respond, I think they will use the full space but need some degree of restraint to keep drag manageable.
    Regards,

    Scott Wordley


    Scoring in every event for the last 12 comps running!
    http://www.monashmotorsport.com/

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