As for the Silverstone round, most cars have been processed and checked, however a few haven't yet, however due to being away at the Silverstone GP, I will upload all the info and legality info and announce the winner on Monday.
variante wrote:Is there any chance to have 3D views with pressure distribution on the bodywork?
At this stage, it is technically feasible but not practical - files become too large to handle and take a very long time to load.
I will prepare the drag/downforce graphs for the past races - and try to also gives access to a csv file with the numerical values so that comparison can be done easily.
Looking at the models posted by Julien, it looks like some have brake duct winglets. Were they allowed? I was under the impression that we werent meant to touch the brake ducts.
All the cars have a winglet on the front as that is what is supplied but the rear shouldnt have anything, from what I can see JJR Racing has created winglets on the rear.
i didn't submit this time, but hopefully for you guys these things are picked up on
in 2014 i hope its slightly different.
heres the 2014 reg boxes, heres some rules you must stick to (f1 nose height, exhaust position, floor rules, tub rules, opening/cooling sizes, min sidepod size etc) - rules that can be governed quiet quickly by simply using some rule boxes. then just have an open field within the reg boxes.
much slacker rules but still based on some aspects of the f1 rule book. at the moment theres a line, but its hard to know where it lays. in the fia regs you can't do this but will the check it if i do it? its better surely (so everyone knows where they stand) to have 5/6 clear rules which can be easily checked, then make sure its clear you are free to do what you like otherwise.
Hi Guys, I must apologise for the lateness of the results on this occasion, a few things have cropped up recently in other projects, I will get the results out as soon as is possible.
hope someone can give us a hand. When you run your own tests do you get the coefficients straight from khamsin or do you get the forces (in newtons) then calculate yourself the coefficients with the relevant calculation?
i only ask, because on the results its in coefficients but then your given the COP which comes from the forces or can you get it from coefficients as well?
I'm just looking to get my results the same way as they are calculated for this.
If someone could give me the heads up would be great. I currently just get the forces so if it is just a case of calculating cl and cd can someone tell me how
Hi Astra,
i don't know if there is an option to convert N into coeff., however you can do calculations by yourself (they're pretty simple):
FROM FORCES TO COEFFICIENTS
-Assuming you're testing an F1 car at 100mph:
DF or drag Coefficient = Force / 1190 (let's call this last number "convertion ratio")
-Assuming you're testing an F1 car at 180mph:
DF or drag Coefficient = Force / 3900
-If you're testing at a different speed, you'll have to trace a curve on a Cartesian plane "speeds(0,100,180) X conversion ratios(0,1190,3900)" and find on the curve the ratio corresponding to your speed.
-If you're NOT testing an F1 car, you'll have a very different frontal area, so previous calc. are not valid anymore. In this case, assuming you know the frontal area, you'll need the usual formula:
DF or drag Coefficient = ( 2* Force ) / ( density of air * speed ^2 * frontal area )
FROM FORCES TO CoP
-About CoP: it is calculated from the axis origin. KVRC guys alligned the front axle with the axis origin, so in this case:
CoP = torque / DownForce on the rear axle
This is it. I hope i've written down the formulas correctly... Remember to use the S.I.
Variante shouldn't you calculate the actual frontal area of the car? Making a quick measurement I saw that with a "low profile" rear wing (monza style) and other differences (lower sidepots and different airbox, but still legal) I have around a 5% difference in frontal area. Since Cd is linear with frontal area, it means it'is 5% off. Quite big error.
Yes you should, but how?
On GoogleSketchup there's no such option to calculate the projected area of a 3D object, so you should do it manually, which means you may still have some error. Maybe you can do it more easily on more advanced CAD programs...
So, yes, if you want a more precise calc. use the last formula, but if you're testing an F1 car following 2009/2014 rules with Hi-DF configuration, use the first two formulas (providing a good approximation); finding the "conversion ratio" for your own car improves the result, obviously.
Hi Guys, been busy with Formula Student, amongst other things, I will publish results tomorrow, and sort out the 3d printing with the winner (Which iteration they want printed), also to answer your question, I am pretty sure we record our data in forces which we then derive coefficients from,
