(KVRC) Variante

[variante]

Hi guys

this is the Monaco spec car: maximum downforce avaiable without compromises. However i should have payed more attention to drag reduction...i didn't know how important it would have been this season...



For Magny-Cours i aimed to reduce drag as much as possible, after seeing Machin's graphs about that track's ideal drag and downforce. So i'm basically running a Monza-spec car:



Here you can see some CFD work done with “Khamsin”, a plugin for Sketchup.
My work was divided into 2 phases:
-studying the effects of the individiual parts of the car (i.e. turning vanes, bargeboards,...)
-vortices management (Y250, bargeboards, rear tires/floor, diffuser, rear wing)
This doesn't mean that i've reached full control on the airflows...i'm still far away from that condition, unfortunately.


as you can see, a lot of optimization can be done here...

If you are curious about something, just ask
After all, we're supposed to share knowledge and experience about motorsport on this forum, aren't we??

[machin]

interesting approach... I must admit that I'm still of the opinion that a medium downforce approach is the best solution for Magny Cours as this example of CSR vs. LB Racing shows... however, if you can achieve a batter L:D ratio than LB Racing achieved then you will be in with a chance... will be interesting to see how you do. I think it is also going to be critical getting your balance correct; balance could easily be what sets the cars apart.

[CAEdevice]

I noticed a small winglet forward the side pods, I'm not sure because I'm using a smartphone with a poor resolution, but it seems to direct the airflow under the floor. This zone should not be included in the flat floor law? I have the same doubt about the flap in front of the rear wheels.

Anyway: what I like most in your car is the simplicity compared to the great efficiency... the contrary of my design


EDIT: the rule that I was referring to is K7.1:

From 330mm behind the front wheel centre line to the rear wheel centre line, and
which are visible from underneath, must form surfaces which lie on one of two
parallel planes, the reference plane or the step plane. This does not apply to any parts
of rear view mirrors which are visible.

I'm quite sure the the winglets in front of the rear wheels and in front of the bargeborads would be not allowed in real F1

[variante]

I'm still of the opinion that a medium downforce approach is the best solution for Magny Cours as this example of CSR vs. LB Racing shows

If they CFD data i got won't be too much different from the official results, and if the projections of your graph when getting nearer to the 0 are pretty much linear...then my car will be way faster than those in your example.

Also, i see LBracing as fast as CSR on that graph, which means that a low drag approach is definitely the best rewarded... We'll see...

I noticed a small winglet forward the side pods, I'm not sure because I'm using a smartphone with a poor resolution, but it seems to direct the airflow under the floor. This zone should not be included in the flat floor law? I have the same doubt about the flap in front of the rear wheels.

Have a look at this (taken from the official F1 regulations):
3.12.4 The boundaries of the surface lying on the reference plane and the point at which the vertical transitions meet the surfaces on the step plane may incorporate a radius no greater than 25mm.
A radius in this context will be considered as an arc of constant curvature applied perpendicular to the boundary and tangential to both surfaces.
The boundaries of the surfaces lying on the step plane which do not meet one of the vertical transitions may be curved upwards with a radius no greater than 50mm which must be of constant curvature.
The surface lying on the reference plane, the surfaces lying on the step plane, the vertical transitions between them and any surfaces rearward of the surfaces lying on the reference or step planes, must first be fully defined before any radius can be applied or the skid block fitted. Any radius applied is still considered part of the relevant surface.


...which translates into article 7.8b of the KVRC regulations.

[CAEdevice]

Take into account that I'm still in troubles with the rules and I don't have a 3D model nor a more detalied picture, but I think that is not a matter of rounded edges: the two surfaces are not lying on one of the two planes and the define e perfect venturi (that is contrary to the aim of the flat floor rule after the wing car years, later modified in the stepped falt floor rule).

Well, if I'm wrong I'll have to congratulate with you... and to start modifying my floor

[variante]

Well, if I'm wrong I'll have to congratulate with you... and to start modifying my floor

don't congratulate 'cause the idea is not mine

[CAEdevice]

Ok, the pictures of the rear winglets are clear. Some doubts about the front winglet: its length is equal to the radius? In the picture it seems to be longer!

I have the suspect that tonight I'll have to do some work

Seriously: I think that that topic demonstrate how important is to see opponent cars (JJR for example!)

[RicME85]

I dont see any issue with what Variante has done, I have done similar in the past.
There is a part of the official rules that allows you to do things from reference plane to 25 or 50mm above (cant remember which) that allows things like this and McLaren's & Lotus' cooling vents.

[CAEdevice]

Thanks Variante and RicME85 for the clearification.

I was confuded because in the pictures the area is not detailed and the length of the floor winglets seemed longer than 50mm (also the curvature doesn't seem to be constant), anyway: congratulations to Variante that has found a simple but efficient solution.

[astracrazy]

your correct, this is all legal as long as the radius in no more than 50mm

with regards to the rear you have to also remember it can not exceed 100mm above the reference plane (as not to break the R75 rule - K8.2).

its good your taking it further and looking into controlling the vortices. Let us know how you get on. I'd perhaps say your y250 needs to be made stronger?

[variante]

its good your taking it further and looking into controlling the vortices. Let us know how you get on. I'd perhaps say your y250 needs to be made stronger?

At the moment, my Y250 vortex is doing great extracting air from under the front wing, and shielding it from unwanted streams. However, it is completely useless for any other aim, since it breaks down very early and then goes up in the sky... Also, i haven't studied its effects on floor sealing yet...

[machin]

If they CFD data i got won't be too much different from the official results, and if the projections of your graph when getting nearer to the 0 are pretty much linear...then my car will be way faster than those in your example.

I'm really looking forward to seeing the results... nobody really managed a good low downforce (low drag) car last year... it will be interesting to see what Cd.A figure you can achieve (and what that corresponds to in Cl.A).

[CAEdevice]

I looked at the charts of Monza and in that case (even more obviously) it seems that a car completely without dofwnforce has great benefits (about 1 second for every Cl.A punit earned, about 8 seconds for each CD.A unit lost). At this point I have a doubt: are "isolines" of the charts linear? They certainly are linear in the typical range ogf values, but they keep linear even with extreme values?

[astracrazy]

with the track characteristics it makes sense though? f1 cars run a special low drag package for that track for example.

(perhaps we should continue this convo in the KVRC thread as to not take up Variante's car thread)

[CAEdevice]

with the track characteristics it makes sense though? f1 cars run a special low drag package for that track for example.

Sure, but I was looking at the values of Cd.A of Monza 2013, and they are higher than I would expect (also considering a 20% more drag for the diffrent rules).