Straight up aerodynamics

[trinidefender]

Here is some good reading that i suggest that anybody interested in the aerodynamics in F1 should take a look at.

http://adg.stanford.edu/aa241/highlift/ ... roach.html
http://adg.stanford.edu/aa241/highlift/clmaxest.html
http://adg.stanford.edu/aa241/highlift/ ... intro.html

I intend to start posting more stuff about aerodynamics and relating them to F1 so hopefully by next season we can have less confusion among people when it comes to "A wing is better because it has more." My main goals are to both educate the forum users and both myself so we can all collectively become better at this.

If you are reading and start to get confused by some of the big fancy words then make a reply/post and either myself or i am sure others will be glad to help.

[trinidefender]

oh and take a look at this twitter page. It has some neat CFD work and links to look at that should be interesting even for those who may not want the headache of all the math. https://twitter.com/momentumCFD

Here is a report about wings, more specifically how they bend in flight and the effect that the changes in camber, bending and twisting has on lift generation. This is all highly relevant to the modern world of F1 especially these days as the idea that every team seems to be chasing is currently flexible front wings. Enjoy!

http://rsif.royalsocietypublishing.org/content/6/38/735

[PlatinumZealot]

If you started with the basics.... that would be great.

[British Menace]

With out hijacking the thread and with your permission trinidefender 111, I would like to contribute here as basics on this are not hard to understand and because of this, primarily, people are all too eager to jump to the highly technical and very deep/ difficult to understand area's which DO have such a large contribution to the F1 sport we love so much

Tied into this. There are some myths out there which some/ most know but are not discussed too much as people hate to admit they don't know as much as they'd like or would like others to think they know....

If all this is ok ...... I would love to contribute here.

Firstly.
Air and the forces it can impart on a race car is all about pressure ..... pressure gradients (The change in the pressure) and is NOT a bunch of particles which hit parts of the car imparting forces on the car in so doing

Regards

BM

[olefud]

With out hijacking the thread and with your permission trinidefender 111, I would like to contribute here as basics on this are not hard to understand and because of this, primarily, people are all too eager to jump to the highly technical and very deep/ difficult to understand area's which DO have such a large contribution to the F1 sport we love so much

Tied into this. There are some myths out there which some/ most know but are not discussed too much as people hate to admit they don't know as much as they'd like or would like others to think they know....

If all this is ok ...... I would love to contribute here.

Firstly.
Air and the forces it can impart on a race car is all about pressure ..... pressure gradients (The change in the pressure) and is NOT a bunch of particles which hit parts of the car imparting forces on the car in so doing

Regards

BM

Oh boy, Bernoulli vs. Newton. How about the air flow creates pressure differences that, in turn, accelerate air particles resulting in reactive forces? Edit- http://www.pilotfriend.com/training/fli ... o/lift.htm

[trinidefender]

Fine by me. I started this thread for people to learn and I welcome people to contribute. I just ask of a few things:

1. That information/theories or what have you is either cited by research papers that are accessible or if it comes from your personal notes as much of my information does it is explained well and in detail. If anybody has read my previous posts I tend to take my time and give a long post with an explanation of why something is the way it is.
2. If a conflict of ideas/information arises, that people don't turn this thread into a flame war. If there is a conflict then I would expect those involved to then refer their theories to research papers and other suitable evidence and the like so that there is no doubt as to what information is correct for potential readers.
3. I ask of the mods to please keep this thread clean of any flaming and "this works the best because I know it does"

Onto the issue of Bernoulli and Newton you are getting into molecular physics and at that point the lines between the two theories start to get blurred.

But please post away and remember, like a proper scientific community does, cite your work and present evidence. Thanks

[British Menace]

Thank you sir.,.
I wanted to wait for you to post again as I wasn't sure on your take on the previous post/ question.
Air "Particles" come in two categories relevant to their size PM10 and PM2.5. These particles are considered contaminates and not "air" pursey.
Having said that ..... When considering such polluted air and the particulate movement with reference to their directional force, you would be right. If said particulates espe ially larger variety (PM10's) "may" impact a part of the vehicle thus resulting in a reactive force.
Depending on the level of contamination, the force contribution would be relatively small.
Sorry, I can site no studies on this one and is, as pointed out, kind of taking us into a very academic area.
Anyway. That's my view would you agree?

Regards
BM

[trinidefender]

I like academics. Bringing that to the table I wonder what impact the different sized pollutant molecules will have in the world of F1. Probably very little, far less than humidity levels which in itself is less than density altitude.

Note: density altitude is the altitude corrected for non standard temperature and pressures. The international standard is known as ISA (international standard atmosphere) which is 1013.2 millibars (29.92) inches of mercury and 15 degrees Celsius (59 degrees Fahrenheit). Wings perform better at lower density altitudes, that is to say in layman's terms that the wing "behaves" as if it is at altitude lower than it actually is. To get a rough figure for calculations with a sea level temperature of around 30 degrees, for every increase of 1 millibar (say 1014 for example), your wing will act like it is 30 feet lower than it actually is. At 15 degrees Celsius it is closer to 27 feet per millibar and at 0 degrees Celsius it is closer to 25 feet per millibar.

I must be rambling by now. But to break it down, wings perform better at lower altitudes, they generate a larger force for a lower angle of attack or at a lower airspeed. The conditions of the tracks can vary enough simply through temp changes and pressure changes that the wing can act like it is hundreds of feet higher or lower than the track is on a "standard" day. This difference is easily enough for teams to measure and can probably upset the balance on some cars.

British Menace, just a curiosity but what field do you study work in? Or is this information from personal sources/reading?

[hollus]

Air and the forces it can impart on a race car is all about pressure ..... pressure gradients (The change in the pressure) and is NOT a bunch of particles which hit parts of the car imparting forces on the car in so doing
BM

Thank you sir.,.
Air "Particles" come in two categories relevant to their size PM10 and PM2.5. These particles are considered contaminates and not "air" pursey.
BM

I have to jump in because my eyes and my brain are hurting. There is no debate on Bernuilli vs. Newton, although people keep debating it. Both work. If the laws of physics are being obeyed, both explanations will produce the same result.
Every single aero force exerted on a F1 car or airplane is the result of molecules (particles) in the air hitting the car or plane. Every single bit of aero force with no exceptions. Now when you analyze the collective behavior of 100.000.000.000.000.000.000.000.000 molecules (10E26, that's 10 cubic meters if I got my numbers about right), then the pressure fields, etc. appear. Humans and computers find it difficult to understand / simulate an amount of bodies in the range of the Avogadro number, but if they could, Newton, one molecule at a time, would produce / predict / explain the exact same results that we explain with Bernoulli and similar and F1 teams calculate with Navier-Stokes.
That this is so difficult to understand is just so frustrating!

[British Menace]

This a misconception.... Air molecules (not particulates!) do not physically "hit" a plane or structure.
Maybe this is a terminology thing it certainly goes much deeper then I first thought.

I have to workbut will return to this a little later if I may.

Regards
BM

[hollus]

Whatever you come back with, remember to obey Newton's 3rd.
But I must agree with you in a way: to keep a plane in the air, much more important that what hits it, is what does not hit it and where it doesn't hit it; or more precisely what hits less often / less strongly in certain well selected places.

[British Menace]

Sorry. I had to come back as this got my mind all over.
I have been so tied up with air passing over, it's activity around an object or surface I have not had to think about this for a long time.
I have to say you are right. Forces imparted on a surface from molecules bouncing off impart a force on that surface plane due to their velocity and mass.

Now clear of mind I have to work.

Regards
BM

[Blanchimont]

Lattice Boltzmann, kinetic gas theory?

[Greg Locock]

I'm amazed by this new theory that wings work by action at a distance. If the molecules don't bounce off each other how do they exchange momentum?

[P.S.]

... If the molecules don't bounce off each other how do they exchange momentum?

Afaik its almost the way you say it. You don´t have a mesh solving navier stokes in it. The room is cut in to cubes and the equation is calculating the probability of molecules colliding with each other on the six sides of the cube.

Sadly this method needs much more RAM than the "old" mesh-method. In generall it seems to have bigger potential and can be used from less educated persons.
A friend of mine tried to switch from open-foam to a lattice boltzmann solution (xflow). But because of his limited hardware resources he decided to go back to open-foam.