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One simple thing to do is add an extra linkage in between to extend threads further out/in. Or an extra point on a bell crank.Quote:
Originally Posted by Big Bird
Now, a suggestion for this topic, we should create a new thread for this because have derailed from the original topic.
UWA already did it with one of their cars (2006 I think). The pushrods had normal adjustability and a 2 position large adjustment as well. Not difficult to implement.
Kev
Wow on the aero changes. A massive change that will almost certainly see a lot fewer teams designing aerodynamic packages. On first glance it looks like a package designed to the new rules may have worse performance than a package designed to the rules prior to the last big change.
I also wonder how many teams will bother to look at DRS now. The narrow, low rear wing will have a lot less drag.
Unsprung mounting for the front wing almost looks like a necessity now. Springs will likely have to soften to gain some mechanical grip back, which will likely require a higher front wing (if sprung mounted).
Trevor is spot on. These rules will widen the performance gap between the haves and have nots, and fewer teams doing aero work overall.
The other sad thing is that Aero helped to encourage weight reduction. With aero the important number is how much downforce divided by car weight for your grip multiplier. Without that weight isn't as big an influence. What you lose on a tyres sensitivity to vertical load, you gain some back on increased temperature. In the past the lighter cars had almost no grip advantage compared to the heavier ones.
Oh well it was fun while it lasted.
Kev
I think the aero rules will widen the performance gap for the teams that aren't doing things right (or as well) in the first place. But it is not impossible to have a high performing car with no wings (UF finishing 9th and Auburn 7th with a 1.7pt gap, Univ Mich in 8th). In the case here, we may see a few of the top non aero cars improve relative to the rest of the competition. Rather, the rest of the competition may see a drawback with lessaero. To me it seems like too many teams were adding wings just to be fast and "competitive" and not understanding the fundamentals of aerodynamics.
A lot of people argue that teams with little resources will be hindered because of this. But has it not always been that way? Some teams have had excellent engine development programs, partially due to the resources they have available, and therefore have succeeded because of that. So to level the playing field should we restrict dyno usage to make the less competitive teams more competitive compared to the better teams? I wouldn't say so. This is a design competition. What everyone should get out of this program, more than anything else, is knowledge. Even if someone is designing wings and they are not able to design wings effective enough to be used with the new rules, they will still be walking out with good experience and research for future members to work off of. The new rules also require more creative thinking and hopefully we see some interesting designs.
Dylan,
I don't think that there is ever a case of "just" being able to add wings. Even if your aero justification is poor you still need to figure out how to make them, mount them, allocate appropriate resources etc.
The argument is not that changing aero rules will disadvantage lower resourced teams. The argument is that restrictive rules favour top teams. This would be true in every area. If you turned around and banned interconnected suspension, beams, CVT's (or put heaps of restrictions to make them much more difficult to implement) you are reducing the areas that a lower resourced, but innovative teams can find an advantage.
If there is only one clear concept to build to the whole competition becomes solely about resources and their management. Everyone is building the same thing. When you have a very open rule set even the super highly funded teams will not be able to try all of the concepts. This has been shown over and over again in professional competition.
Also sorry to be an arse but finishing 9th is not high performance. The delta in each of the events to a highly resourced and big aero team (GFR) was:
-3.7 pts Accel
-20 pts Skidpad
-49 pts Autocross
-73 pts Endurance
- 16.5 pts Efficiency
~162 dynamic points deficit.
smaller, but still large deficits to other top aero teams.
Sure the best non-aero cars can beat lower performing aero cars, but you would have to make a very good case for making the statement that the best non-aero cars can compete on a level playing field with the best aero cars. You mention teams not knowing fundamental and implementing wings just for speed, but if your team had made the right decisions you would also be running wings, and be closer in performance to the better teams. I'm not writing this as an attack. But if your points calcs say that you should be running wings, and you don't run wings, then you are making a bad engineering decision. To criticise teams that implement wings on this basis, but do so without full knowledge is a practice in hypocrisy.
Kev
So I guess here is where we define what a high performing car is. If you look at the rest of the top ten teams, where would you make the cut off for a "high performing" car? There is definitely a large gap between my team and GFR (as well as some of the other top teams) and I will never deny that. And saying "beat lower performing aero cars" is somewhat degrading when you look at a top 10 finish (as well as top 10 in Endurance). I also want to be clear that I never said the best non-aero car will be able to compete at the same level as the best aero car. From what I have seen in the competition in the past few years, aero is definitely the way to go for higher performance on the track and my team won't deny that.Quote:
Originally Posted by Kevin Hayward
Now why are we not running aero? Because of resources! We could come up with a simple airfoil geometry, make the molds, and get wings on without good understanding of the actual profile and aero effects, but where's the fun in that (aside from driving a car with big wings)? Sure we may have seen dynamic performance benefits, but what would you call a worse engineering decision, putting wings on without good understanding of their effects (aero balance, suspension loading, profile design, etc...) in order to, hopefully, increase dynamic performance or having that as a side project for development in future until the team can learn these fundamental effects from the system? And yes, calculating things like the extra loading from aero isn't too difficult, but it also extends into more areas such as rotor design to ensure we won't see failures from the extra forces.
Dylan,
I don't mean to degrade anyone's attempts. I don't think that a team needs to be the best team in the world to achieve good learning outcomes and do a good job. To put a definition on it I would say high performance would mean:
"The car and team are in the running to win the competition. This might be by purely beating everyone, or being good enough that they could take a win if a couple of better teams fail to finish endurance."
I don't like basing a definition on finishing place at all, but the idea of being in the hunt gives some credence to the idea that amongst the higher performing teams there is some trade-off between reliability and performance. It might be better to talk about targets, ie. a concept / team that is capable of scoring within 20-40 points of the best assuming:
4.8 skidpad
4s accel (or whatever history shows as the ideal accel time for IC - obviously contentious here.
some delta to best laptime (maybe this is best done with lapsims and search algorithms, rather than off data)
3L 98 fuel equivalent used (or similar target).
Finish all dynamic heats
We are trying to look at the top 1-2%. Probably works out to be whatever the top 3 does in any given comp. The top 10 includes about 30% of the finishers in a given event. Not even the top quartile. If reliability is evenly distributed amongst the teams (which it is not) that would mean had everyone finished in a 100 cars the 10th place finisher would have finished 33rd. In the case of the comp you mentioned 9 teams that finished below UF had an equal or better autocross score, 13 had a better skidpad score, 18 had a better acceleration score. Prior to the endurance UF was in 18th place dynamically. The top two overall were still the top two, in fact the top 4 overall were in the top 5 dynamically before endurance and pretty much in the same order. Their finishing place was not really determined by anyone else dropping the ball. Too many teams running in the midpack of finishers underestimate how far ahead the high performance teams actually are. This is not a particular attack on UF, or anyone else in a similar position.
In engineering design it is very clear that mistakes in conceptual design are much worse than mistakes in the detail. So yes waiting on implementation to understand the fundamentals, when you are aware of the definite performance benefit that is able to be implemented is the worse engineering decision. Any other statement would go against research and general understanding of the engineering design process.
It is a scientist who waits, the engineer acts.
As for the practical implementation molds aren't required, wings can have fibreglass or aluminium skins. The only reasonable resource limitation is manpower. I am familiar with the UF cars. Beautiful bodywork, and I love the Gulf colour scheme. If you can do that, you can do wings (maybe at the expense of less time on the beautiful bodywork). The understanding (aero balance, suspension loading, profiles) required for initial implementation can be found very easily. McBeath's competition car aero goes through a lot of the good basics with some reasonable numbers, combine that with some Benzing profiles (available on the net), and read the monash papers. You can design and build a pretty good package quite quickly.
The first ECU aero package was designed an built by a couple of first year students in about 6 months and improved laptimes by about 2 seconds over a 60s lap. Later, better built, lighter, more efficient designs followed. This process is improved becuase you have actual data and testing of the more agricultural versions. Needless to say none of the detailled improvements even come close to the initial advantage of having them vs not having them.
I know you probably think this is another response from a guy being a jerk rather than someone trying to point out objective engineering ideas. Sorry for that.
Kev
I have to step in and disagree with the idea that these restrictive aero rules favour the teams with more resources. If there is less potential down-force to be had from aero, then throwing massive resources at it will only gain you 5% now not 20% (not actual values). Teams that weren't running aero before, or were running crap aero (and now won't bother) will able to waste less time designing/debating aero and get on with the rest of their. Ultimately their performance will remain more or less the same and the teams that get huge benefits will now be going slower.
Case and point, because I like my old team: Brunel finished 11th overall at FSUK, I think that's 7th Combustion team, so I'm gonna say they'd have been top 10 if they'd been at Germany this year. The teams biggest drawbacks, as they have always been is budget (mnot tiny, but definitely limited), experience (30-odd brand new team members each year, 5-6 team managers that were new team members the previous year, no useful staff involvement to help carry over knowledge), AND manpower during the build phase (no accomodation provided over summer, so rarely more than 5 or 6 people actually end up working on the car at any one time, often less).
I won't go into all the reasons why, but essentially they end up scraping a car together less that 2 weeks before competition (sometimes much less) and don't really bother preparing statics because they don't have the time. Poor management (due to lack of instruction how to) plays a part.
So top 10 combustion is a pretty good result all things considered. If the team get their act together and start prepping for statics properly and maybe get a car built early enough to improve on the dynamics, then they would glide into the top 5 I should hope. Challenging for the top spot is perhaps a bit of a push, but for a car without aero that's pretty good.
We have been working on aero lately, but didn't get enough testing or data to run at FSUK. They may run it at FSCzech, but ultimately this year's package was about data gathering. Whether or not this data combined with the new aero rules means that they go ahead with a full aero package next year or not, I don't know, we'll see. But if they have the potential to challenge for top 5 wihout aero, then so do 3/4 of the teams out there, and that's with the current rules!
What frustrates me regarding these rules is there is little transparency as to why the rules were changed and why aerodynamics been targeted. Especially when there are other more serious safety issues present. There are only anecdotal reasons I have seen given for these changes, from the survey and FSAE Forum:
• It is often commented by judges, officials and others that have been involved in the various competitions for many years “wouldn’t it be great to change the rules to offer the students a new challenge”.
• A few of the better funded teams have done well with large wings that attempt to fully exploit the aero regulations, but it has been noted that many teams have followed down this path because other teams have been successful rather than because they understand how the benefits will be achieved.
• It is likely that the aero regulations will need to change in 2015 as there are concerns that the wings are too large, several wings have detached from cars causing concern about the safety of marshals and some of the cars have become unstable such that in several cases they have almost rolled over.”
• This was done because the rules committee was of the opinion that too little research into aerodynamics was done. They now feel that the time is there to tighten the rules again and make it a bit harder to create a beneficial aero setup.
1, The students don’t need greater challenges, the finish rate for fsuk and Michigan enduro was 24% and 32% respectivel.) So increasing the challenges is not relevant to most team. Why is this massive lack or reliability not being addressed?! 2. If teams are copying other designs this should be assessed in the design event and other areas can be just as easily copied as well 3. This seems like a knee-jerk reaction: Plenty of cars at fsuk and fsg caught fire or had carbon suspension which were arguably of greater risk, yet no-one even mentioned these occurrences. (I find it amazing that the area of failure, cause and effect is not recorded at competitions, so statistics on these can be gather to guide rules and safety in the future) 4. And the last one, basically they're offended by the size of the current wings… ?
There was an attempt to gain feedback from the FSAE community with the survey. Which now appears unlikely that the results will ever be published, I am unsure if they were even considered? (Why did I bother spending the time to reply!) What happened to this?
A1.1.1 of the rules state, the rules are to: “give teams the maximum design flexibility and the freedom to express their creativity and imaginations there are very few restrictions on the overall vehicle design…. The competitions themselves give teams the change to demonstrate and prove both their creativity and their engineering skills in comparison to teams from other universities around the world”. Yet the design flexibility is being taken away for little reason. They also restrict the ability of teams around the world to compete, as many Australian Teams would need to re-design half built vehicles to be rules legal for 2015. Further, teams can and will fit wings which fit within the boxes given, and it will reduce some of the questions raised by the compromise between cg height and rear wing height/size, reducing the potential to learn from these situations.
In my opinion the further the rules are restricted and have large changes implemented this leads to greater uncertainty,further increasing the gap between the big and small teams as they have the ability to better react to changes, this decreases safety as smaller teams alter designs to suit changes with limited time to consider all consequences, reduces the ability of teams to compete internationally, reduces teams ability to implement any sort of multi-year planning and reduces the range of concepts and approaches available to teams.
Westly
Edit: Dunk, I agree you don't need Aero to place well. FSUK showed that reliability and preparation are king. (14th place was the 500pt cross over and 350 points separated those teams. eek!). With roughly 30 points separating each team, alot of technical improvement is required to make that gap up, ~35kgs of weight reduction, or significant Aero improvements based on our lap simulations. Aero was a good place for teams to actually gain significant performance benefits from technical design when your in the top couple of placings at competition. But the deciding factor to doing well was preparation and reliability in the end, so sounds as though Brunel was lucky more than anything if they finished 2 weeks before comp, and with little testing finished endurance.
Good teams are good, not because of their aero but because of their management, which is why I didn't believe the Aero rules needed to change. Aero was just another feather in their cap, but isn't worth 100s of points like some people believe.
Driver Training, Reliability, Preparation and statics are now even more important with these rules, with Technical Performance Potential between different concepts becoming even closer.
Sorry for writing an essay.
Dunk,
I'm going to echo Kevin by saying this, and like him I don't mean to sound degrading.
However, as close to the top as an 11th overall spot might sound, Brunel were over 260 points behind fifth place.
It seems to me to be a bit of a stretch to suggest that that difference (almost a 50% points increase for Brunel) can be overcome by driving a bit earlier and better statics preparation.
Unfortunately the scores of the teams just outside the 'top' drop off very quickly.
Thijs