(KVRC) Variante

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MadMatt
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Re: (KVRC) Variante

Post by MadMatt » Sun Oct 12, 2014 9:24 pm

This is correct! Tuning the slot gap is the main part of the job and it is also what I found when I designed a 2 elements rear wing using 2 identical existing airfoil profiles (and simulating this in FoilSim). You seem to know your stuff, personally designing airfoil profiles is one of the box I want to tick one day so I salute your work! :)

variante
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Re: (KVRC) Variante

Post by variante » Tue Mar 24, 2015 10:07 pm

Here is the fourth generation of Variante cars, the Livore. It has been designed for the 2015 KVRC aerodynamics challenge.

Technical analysis, CFD screens and data after the first race.

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CAEdevice
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Re: (KVRC) Variante

Post by CAEdevice » Tue Mar 24, 2015 10:13 pm

I'm hating my smartphone... I have to make strange workaround to load the pictures!

machin
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Re: (KVRC) Variante

Post by machin » Tue Mar 24, 2015 10:21 pm

Now...That....is.... AWESOME!

I can't wait 'til we get some numbers off of that thing!
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CAEdevice
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Re: (KVRC) Variante

Post by CAEdevice » Tue Mar 24, 2015 10:23 pm

ok, I have seen it.
Your modeling is a step above mine and the aero seema more.consistent.
You have full covered suspensions: I tried the same at first but I could not make it work... but if you did I'd have a reason to believe that some numbers I read in the KVRC thread are effective!

RicME85
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Re: (KVRC) Variante

Post by RicME85 » Tue Mar 24, 2015 10:40 pm

Wow! That front wing!

MadMatt
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Re: (KVRC) Variante

Post by MadMatt » Wed Mar 25, 2015 7:18 am

I will put comments tonight, but it looks even more aggressive than Matteo's creation, Peugeot 905esque!

chuckdanny
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Re: (KVRC) Variante

Post by chuckdanny » Wed Mar 25, 2015 1:43 pm

You can't turn the wheels, can you ? :lol:

turbof1
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Re: (KVRC) Variante

Post by turbof1 » Wed Mar 25, 2015 1:48 pm

That's very nice. I'm noticing quite a bit of influence from the previous F1 platform.
#AeroFrodo

CAEdevice
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Re: (KVRC) Variante

Post by CAEdevice » Wed Mar 25, 2015 3:38 pm

Ho Variante, finally I could take a look to your car with a decent resolution.
I have the impression that the gurney above the diffuser does not extend until the superior limit allowed by the rules. Is that right?

MadMatt
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Re: (KVRC) Variante

Post by MadMatt » Wed Mar 25, 2015 5:41 pm

Ok so here we go!

1) If you managed to balance that HUGE front wing with the rear end, fair play to you, I guess I won't stand a chance against the clock if you did!

2) Interesting but borderline idea to move the engine inlets at the rear. You are really stretching the "plausible path to the engine" :P

3) I like the detail you've put in trying to get the air to fill the wake behind the car in different ways, that's nicely refined!

4) We cannot really see your diffuser, but by the looks of it you did not extend the strakes down to the floor. This highlights the fact that there is no universal aero solution, and that each car requires its own features to work well!

5) You've try to create some vortices, I salute you as this is something I didn't have time to explore!

6) Interesting also how high you've placed your mirrors!

It will be interesting to see how your car performs but it looks really good! =D>

variante
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Re: (KVRC) Variante

Post by variante » Wed Mar 25, 2015 7:03 pm

Thank you, guys!

Let's answer some questions...
CAEdevice wrote:Your modeling is a step above mine and the aero seema more.consistent.
You have full covered suspensions: I tried the same at first but I could not make it work... but if you did I'd have a reason to believe that some numbers I read in the KVRC thread are effective!
I don't think my modeling is better...as a student, i just have more time to lose...
Jokes aside, i've gone for the full covered suspensions because it seemed to be a flexible layout: good at keeping the airflow clean to the rear, especially.
chuckdanny wrote:You can't turn the wheels, can you ? :lol:
Let's just say that the turning radius is going to be quite inappropirate if you want to drive it in some old italian village...
turbof1 wrote:I'm noticing quite a bit of influence from the previous F1 platform.
Indeed. I've abandoned the classical LMP bodywork configuration...I've decided to move the radiators/sidepods as forward as possible, even risking some blockage at the front, in order to obtain the greatest (and most efficient) airflow to the rear end of the car. This layout also gives me the chance to put here and there other winglets without many interferences from the main bodywork.
CAEdevice wrote:I have the impression that the gurney above the diffuser does not extend until the superior limit allowed by the rules. Is that right?
I don't remember...It's 55mm. That's more than enough, honestly (unless you want to make something like last year McLaren mushroom suspensions...).
MadMatt wrote:2) Interesting but borderline idea to move the engine inlets at the rear. You are really stretching the "plausible path to the engine" :P
If the engine is turbocharged (and that's not specified by the rules), those inlets won't be an issue :p
MadMatt wrote:4) We cannot really see your diffuser, but by the looks of it you did not extend the strakes down to the floor. This highlights the fact that there is no universal aero solution, and that each car requires its own features to work well!
Correct! Every layout reacts in its own way... In my case those strakes do suit the best. It's all due to the vortices they produce. BTW, i'm using a modified version right now.
MadMatt wrote:5) You've try to create some vortices, I salute you as this is something I didn't have time to explore!
This is an area i would have liked to explore more, but i haven't had the time... Last iteration of last year car, the F1 model, had a much better vortex management...
MadMatt wrote:6) Interesting also how high you've placed your mirrors!
Just as far from the bodywork as possible! ...and as out of the rear wing's way as possible!

variante
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Re: (KVRC) Variante

Post by variante » Tue Apr 14, 2015 9:14 pm

As promised, an analysis concerning the aerodynamics of the Variante Livore

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Designed to achieve the greatest amount of downforce, it managed to win the first race of the KVRChampionship which took place (virtually...) on the Nurburgring Nordschleife.

This iconic track demands a very high level of downforce as the car has to handle more than 70 tortuous corners at very high average speeds. The presence of long straight lines, however, imposes the production of downforce to be decently efficient, as opposed to tracks such as Monaco.

The Livore was, indeed, originally designed to produce large amounts of downforce in the most efficient way in order not to repeat last season's experience, where a generally good car -the Variante Ira- was limited by its high drag characteristics.

To achieve that target, the classical LMP bodywork design was abandoned in favour of a more radical approach, characterized by a water drop-shaped front end followed by a tight rear bodywork: a solution that allows for a greater airflow to the rear end of the car. The water drop shape itself has got intrinsic low drag characteristics and is very stable when subject to aiflows coming from different directions (meaning, for example, that this part of the bodywork will be easily adaptable when the Front Wing AoA will be changed for the following races).

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About the FRONT END
Despite being designed, originally, similarly to an LMPrototype front end, the increasing level of downforce required to balance the rear diffuser and wing imposed a heavy revision of this area, now characterized by a massive double tier wing.

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This layout was chosen over the classical diffuser shape in order to minimize the connections and interactions with the following bodywork, thus minimizing downforce dissipation (which can be observed anyway, in a smaller amount, on the top of the front suspensions cover...).

About the MAIN BODY
Integration of the parts and overall elegance were keywords for this car. This chain of interactions explains what it really means:
The front suspensions/wheels cover, receiving air from the front wing in the least intrusive and most gentle way, directs the airflow around the sidepods and to the side impact structures cover with the optimal orientation; the latter are shaped so that they generate a moderate amount of downforce not to disrupt the airflow to the rear wing, which gets cleaned up and redirected by a winglet over the rear wheel arches, which also houses takes advantage of the exhaust pipes that, in turn, accelerate air to the rear wing.

About the REAR END
Quite obviously, the two protagonists of this area are: diffuser and rear wing. While for the wing the only development work concerned airfoils, the diffuser required a far greater effort. That is an element capable of generating more than 50% of the total downforce, so it's definetely worth putting some effort in it...

The diffuser funcions tridimensionally, therefore both its profile and its plan view shape had to be developed in parallel. As for the profile, maximizing airflow extraction and acceleration from the undebody was the main aim, which has been fullfilled using a hybrid diffuser (concave/convex). On the other hand, the plan view shape had to be designed considering the inward suction, caused by the low pressure under the car, and the strong inwash, caused by the tyres.

While inward suction and inwash may be seen as negative aspects that increase pressure under the body of the car and disrupt a linear airflow, they can be used in a constructive way: in fact, the so formed transversal flows can interact with the walls of the diffuser, shedding one strong vortex each side of the car, thus increasing downforce and flow predictability along diffuser's lenght.

Finally, well studied strakes have been a determinant factor in further downforce production, as they have the property to stabilize the flow, ridistributing pressure zones in strategic points, as well as energize it shedding smaller vortices.

I cannot show pictures of the diffuser, for obvious reasons, but here are the forces distribution:
Drag
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Downforce
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Hope this helps a bit those who are new to aerodynamics.
If you've got questions or want me to describe a topic depth, just ask :)

machin
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Re: (KVRC) Variante

Post by machin » Tue Apr 14, 2015 10:05 pm

variante wrote: If you've got questions or want me to describe a topic depth, just ask :)
The diffuser..??!!!

:lol:

Seriously.. nice article.
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crxdave
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Re: (KVRC) Variante

Post by crxdave » Wed Apr 15, 2015 7:11 am

machin wrote: The diffuser..??!!!
.
+1 :D
On a serious note, inwash from the rear wheels is one thing I am struggling to contend with - any friendly tips?

How are these flowlines achieved in (I presume) paraview? Image