Golf ball aerodynamics in F1

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Aerodramatics(UK)
Aerodramatics(UK)
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Joined: 10 Oct 2004, 16:39

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Monstrobolaxa wrote:You are also forgetting... .
Fair points, one and all...! :oops: I figure that the flow-field about an F1-car through its operating speed range is a complex mixture of laminar, transitional and turbulent boundary layers, each with specific pros and cons, dependent on the functional design and local pressure-field about each component... ! So purely laminar flow boundary-layers won't necessarily dominate all components, although I appreciate it may dominate up to the peak suction/roof-top/pressure recovery in terms of the aerofoil design for the wings.... :-$

I think the airflow direction issue you raise could sometimes be crucial - and sometime a red herring!- for eeking out the last few hundredths of performance from the aero package (although as always real-world track and race conditions are the ultimate arbiter)... choosing the 'most appropriate' onset assumption could subtly influence and even bias design decisions and technology development paths in the wind-tunnel and CFD design environment.

When I think of the mixed, compressible flows, with unsteady flows and wakes and deformed tire 'jets' from the steered wheels interacting with the quasi-'steady' flowfields of the bodywork, votical flows & vortex bursting and strongly-coupled wakes of the multielement wings, together with the circulation dumping and generation that go hand-in-hand with a heavily braking and accelerating racing car and then add the angular velocities under-cornering + changes in ride-height due to an undulating track and pitch (roll, yawing) chassis + the random effects of windshear, + heat transfer and variable density in the rad duct and exhaust flows it's impressive that F1 designers keep the problem tractable and steer a practical path, distilling sensible on-design points, then identifying key flow structures and interactions and tweeking and honing these, whilst also keeping the whole vehicle optimisable in such short shrift whilst subject to the constraints of systems integration and regulations! - its no wonder the racecars aerodynamics are sensitive to blatting through the total pressure loss mess of other cars "slipstreams" !!! :) - the aforementioned being just my own off-the-top-of-my-head brain-dump of the biggies... though no doubt others in the know could add more... masochists might even add transition mechanisms including bypass & receptivity! At least there's no shock waves to worry about yet - engine & exhaust system excluded !

On the other hand w.r.t. question of the necessity for the prescence of natural turbulent b.l.s to benefit from surface drag reduction technologies, fish are relatively low-Re devices (say 20-30cm one anyway!) - not sure if the scales do the trick or it's just surface 'smoothness', but I'd agree that sharks (and their skins) do seem to favourable interact with the energy cascade in turbulent flow energy spectra... what is nature up to, I ask?

Maybe, as Lewis Richardson paraphrased:

"Big whirls have little whirls, that feed off their velocity, and little
whirls have lesser whirls, and so on to viscosity".

with the usually appologies to Lewis Caroll !! :mrgreen:

My limited hard-earned design experience in life so far has slowly taught me to recognise, that one rarely needs to fully understand how something works, in order to take advantage of its beneficial effect in design... : #-o :lol: Indeed, if at first you don't succeed, try, try again... though some understanding helps of course, when choosing the right parameter to vary and gain even more performance ! But with complex problems, after resorting to much head-scratching, "suck it and see" seems a perfectly valid approach!

Even so, I'd say we all should keep working to improve our knowledge and stay open to new ideas, concepts and ways of thinking - after all it can be a fun (but sad and twisted) way to pass some time ! - 'get a life!', as they say 8)

But coming back to Tim's "What if?" question ....given the large wetted area of the non-downforce surfaces cf. the downforce surfaces on an F-1 car, perhaps a theoretical - albeit small - drag reduction is there to be had, if desired, laminar flow regions and cross-flow induced separation notwithstanding.... commercially available 3M-style apliques may yet find an application somewhere.... then, again :cry:

To buy shares or not to buy shares, THAT is the question.... :?:

with my appologies to Shakespeare !!! 8)

P.S.: Now that's what I call a big post - and mispost below, bloomin' logins - moderator please delete my guest post below!!! :shock: Sorry, y'all ! :D
Last edited by Aerodramatics(UK) on 11 Oct 2004, 10:49, edited 9 times in total.

StiK
StiK
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Joined: 31 May 2004, 20:43
Location: Portugal

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One thing that i noticed is that people think that golf ball aerodynamics is just a way of reducing drag! Well, not directly because the only purpose of golf ball aerodynamics is to delay bondary layer saparation, and that is what causes a lot of drag. That's why swim suits have fish like textures, because we humans are bluf bodies and bondary layer separation contributes to drag much more than skin friction drag. So sometimes is better to have a turbulent bondary layer, which is more energetic and so less prone to separate but causes more skin frition drag.

Aerodramatics(UK)
Aerodramatics(UK)
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Joined: 10 Oct 2004, 16:39

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StiK wrote:One thing that i noticed is that people think that golf ball aerodynamics is just a way of reducing drag! ...
Do you mean people in general, or on this thread?

If you say on this thread, you're not being very fair as Tim, Tomba & Reca (& MB!) each provide a valid , concise description.... i.e. that pressure drag is reduced due to the reduced seperation zone because the turb. b.l. separates later than the laminar.

Obviously, one could even go on discuss the energy ratios of the two b.l. types, etc. etc. as is usual in most undergrad course on 2D b.l.s.....yawn But no need to bore people even more!!

BUT TIM did raise the interesting question of low-drag textures, as well as the golf ball principle, which I think is an interesting ongoing research area in aerodynamics all by itself...

Btw, Are you familiar with Bob Liebeck's pioneering work on laminar flow high lift aerofoil optimisation in the late sixties and early seventies? - here's a case where turbulent flow CAUSES early separation along the design pressure recovery gradient to the trailing edge -oh dear! :evil: :twisted:

This is an important exception to the energetic b.l. argument for F1 applications, methinks... here a turb. b.l. generated too soon gets big anf fluffy and becomes more susceptible to the adverse pressure gradient of the pressure recovery to the trailing edge (and , NB, doesn't experience the same pressure distribution up to usual pressure recovery ramp)... or so I've been told by those with more experience in these matters ! :roll: :wink:

...and undoubtably this can potentially be a source of much anguish to a budding F1 wing designer - btw, at the full scale design point I'd guess about 20-25% chord flow is likely to be laminar before being tripped by the pressure recovery for current regs :P

If not, no harm done...! 8)
Last edited by Aerodramatics(UK) on 16 Oct 2004, 00:39, edited 7 times in total.

Monstrobolaxa
Monstrobolaxa
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Joined: 28 Dec 2002, 23:36
Location: Covilhã, Portugal (and sometimes in Évora)

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You forgot to mention me! :P though I don't mention it in this thread...it was implied! :lol: and I also mention it in other threads at least in one of the ones that are linked! :lol:

Aerodramatics(UK)
Aerodramatics(UK)
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Joined: 10 Oct 2004, 16:39

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Monstrobolaxa wrote:You forgot to mention.... :lol:
MB,

not for the first time in this thread either!!! Sorree :wink:

Btw, does your thread handle translate the way I think it does?! :P

StiK
StiK
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Joined: 31 May 2004, 20:43
Location: Portugal

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I meant generally and also in this forum :shock: :shock: . Well, since this is not the first forum where this is talked about and i read this forum posts very quickly i got a wrong idea. My apologies to those people refered by Aerodramatics(UK).
Aerodramatics(UK): It´s the first semester that i'm having fluid mechanics(which since i'm studying Aerospace Eng. is only aerodynamic related). I´m still learning alot of things and the book we are using is very extensive. So i hope that by the end of this year my knowledge is far better than it is now and we can discuss this things more deeply!!! 8) 8)
Monstrobolaxa: I've been to Covilhã this weekend because of AirCargo2005 and i've been at your uni.

Once again, my apologies.

StiK

Monstrobolaxa
Monstrobolaxa
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Joined: 28 Dec 2002, 23:36
Location: Covilhã, Portugal (and sometimes in Évora)

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OH.....and you didn't tell me in advance! A friend of yours ("pyrex"-Valença Pires) was here and he looked for me...but I didn't go to the aircargo challenge! But luckly you'll see me there next week....I'm more or less the tek. director of a new team....last night I arrived at the lovely number of 480N of Lift....with only 30N drag.....but only for the wing :lol: :cry: ....now the fuselage.....let's see what I can do with it! :lol:

StiK
StiK
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Joined: 31 May 2004, 20:43
Location: Portugal

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Unfornuatally i didn´t remember to warn you! :cry: It would be interesting to discuss directly with you and in portuguese!!!! :D :D

I was the co-organizer of the fist AirCargo and now i´m in the IST team.

I´ve heard some values about the maximum takeoff weight and last year the maximum was 7Kg from Braga so considering that the wing span is lower, problably the best takeoff weight will be lower than 10Kg.

Cheers!!

StiK

Monstrobolaxa
Monstrobolaxa
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Joined: 28 Dec 2002, 23:36
Location: Covilhã, Portugal (and sometimes in Évora)

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But are you talking about the maximum takeoff weight (plane + cargo) or the maximum payload (cargo)? Our Beluga has a maximum takeoff weight of around 25 kg....but only 5 kg are from cargo!

Well I'm planning a carbon fibre fuselage and wings.....(I just hope that the materails lab gives us the carbon....we do have it....but no one uses it)!

StiK
StiK
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Joined: 31 May 2004, 20:43
Location: Portugal

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I was talking only about cargo weight. The two Covilhã planes had one big problem: they where to heavy. Coimbra´s plane was the lightest weighting about 6 kilos. At the moment there is only one team competing for IST which is a shame given that our lab is being equiped and there is a great potencial being wasted!! The problem with carbon and glass fiber is that it is too expensive. We are abandoning that material given that there are very good alternatives much cheaper!

StiK

Monstrobolaxa
Monstrobolaxa
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Joined: 28 Dec 2002, 23:36
Location: Covilhã, Portugal (and sometimes in Évora)

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Well I don't think glass fibre is that expensive.....I've been building prototypes for the Shell Eco Marathon (at home) as an independant team...and due to the lack of sponsorship I pay everything from my own pocket (around 2000 euros/year - engine+trans+chassis+bodywork)....and fibre glass is fairly cheap!...but at the end we never go to the race (we only went in 2001) cause we spent all the money on the prototype! :cry: :lol:

About the aircraft we really don't have a money problem.....the limit is around 2500€/aircraft! But there is a limit of 2/year....and now we have 6 possible teams!

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machin
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Joined: 25 Nov 2008, 14:45

Re: Golf ball aerodynamics in F1

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I was flicking through a new car magazine in the local newsagent at the weekend and they had some pictures of some new tyres which have dimpled side-walls. The explanation for their inclusion was lower drag and noise.

I think the magazine was something like i-motoring or i-motors.. ? Something like that... Can't find a link on the web though....
COMPETITION CAR ENGINEERING -Home of VIRTUAL STOPWATCH

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HampusA
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Joined: 16 Feb 2011, 14:49

Re: Golf ball aerodynamics in F1

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Random fact: If you were to take the whole world and shrink it to a golf ball´s size. It would have alot smoother surface then a golf ball.
Despite we having mountains like Mount Everest etc.
The truth will come out...

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MIKEY_!
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Joined: 10 Jul 2011, 03:07

Re: Golf ball aerodynamics in F1

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I reckon golf ball surfacing would work well. I helps the air flow to stay attached to the surface. Useful if you could get it around the rules that stopped winglets.

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Maggot
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Joined: 12 May 2011, 14:50

Re: Golf ball aerodynamics in F1

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firstly i Apologize for not reading through the entire thread before posting this, but i have thought about this for a while now,.. and think Ferrari and RB are already using a similar technique (golf ball) aero, maybe a larger carbon fiber weave,? to create the bumps? I have not seen it on any other cars, and it differs form track to track, no all tracks have this "golf ball paint" some tracks are smooth

also on Ferrari photo, people have commented on poor painting technique, but if you look closely you can see the weave (highly doubt its a shoddy paint job, on a car that has millions invested in it,.. all other cars are smooth.

Rb = on side pods and engine cover

Any thoughts ?

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