Khamsin Virtual Racecar Challenge 2015

Post here information about your own engineering projects, including but not limited to building your own car or designing a virtual car through CAD.
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variante
133
Joined: 09 Apr 2012, 11:36
Location: Monza

Re: Khamsin Virtual Racecar Challenge 2015

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Good news, Matt!

BTW if the Cl.A thing surprises so much, i start wondering whether i did something wrong with my simulation settings... :D
I wouldn't like to have bad surprises in the first race because of this; i'd rather prefer someone else beating me with a staggering Cl.A=15...

Still, if my results are reliable, the efficiency and the balance are good as well as i focused on the underbody and "internal" airflow control rather than wings' AoA.

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CAEdevice
48
Joined: 09 Jan 2014, 15:33
Location: Erba, Italy

Re: Khamsin Virtual Racecar Challenge 2015

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Don't worry, I'm not satisfied at all with my car. Cl.A is around 5.5-6... or I should say "was". I started testing a model with OCCFD, but only 1 run every 10 was cmpleted without errors, so I swithced to SWX Simulation and I developed the car, apparentely increasing the performance. Finally I tried to switch back to OCCFD for a final test, but the results were disappointing... performance was much worse. I really don't know wich direction to take, so I'm quite frustrated. At least, the car is almost legal and I'll take part to the first race anyway.

MadMatt
MadMatt
125
Joined: 08 Jan 2011, 16:04

Re: Khamsin Virtual Racecar Challenge 2015

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Matteo I have the same situation. Out of the few models I was able to simulate some time ago, the results were different from the software I am using usually, so really I don't know where to go with the development, but we will see!

Variante, you might have built a killing machine, we don't know! :D If I can give you an advice, it would be to go to OCCFD as soon as possible to avoid surprises (like Matteo and me). I find it hard to see how internal flow is managed with OCCFD so I am leaving this on the side, I just concentrate on putting the inlets/outlets in places where they will not interfere with the flow rather than using them to my advantage.

Like Matteo, I am not that happy with my model, I tried to go with a design that was different with what we usually see in LMP1, but I think I haven't been able with this version to achieve what I was hoping. There is scope for improvement of course, but my initial tests were not that fantastic.

But as they say, its never over until its over, especially not what it hasn't even started, so let's see, I can't wait to see people's designs!

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CAEdevice
48
Joined: 09 Jan 2014, 15:33
Location: Erba, Italy

Re: Khamsin Virtual Racecar Challenge 2015

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I think that, as it happened during KVRC2014, the first race will be part of the developing stage (full results will be downloadable, is it confirmed?)

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machin
162
Joined: 25 Nov 2008, 14:45

Re: Khamsin Virtual Racecar Challenge 2015

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Guys, I've unlocked the COP function... link below:-

KVRC Test Track

But as per one of my previous comments; don't get hung up too much on the Balance in the high downforce tracks...Simply piling on more downforce (even at the expense of efficiency) is better than a trying to find the optimum balance, as the examples below show:-

The first test has 5:1 downforce:drag ratio and is perfectly balanced. The second car is unbalanced and has 200% more drag, however, it also has 80% more downforce (even so, the efficiency has fallen to 3:1), and the result of all that downforce is that it is quicker...

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Of course, you shouldn't just completely forget about balance; just don't worry about getting it perfect... and one thing is for certain; don't take any downforce off to aim for better balance: at the high downforce tracks you should always add downforce at the deficient end.


Oh, and there is no "adjustment" made to the COP in Virtual Stopwatch itself... the previously discussed adjustment will be made prior to putting the figures into Virtual Stopwatch.
COMPETITION CAR ENGINEERING -Home of VIRTUAL STOPWATCH

MadMatt
MadMatt
125
Joined: 08 Jan 2011, 16:04

Re: Khamsin Virtual Racecar Challenge 2015

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Downforce is really the number 1 thing, then. Its a bit of a shame since its influence over efficiency is way too big imo, but that's just me speaking here! :)

I cannot wait to see what the teams will do for this first run and if someone will break into the "CL.A 10" barrier! For me this has become "a thing"!

cdsavage
cdsavage
19
Joined: 25 Apr 2010, 13:28

Re: Khamsin Virtual Racecar Challenge 2015

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MadMatt wrote:Downforce is really the number 1 thing, then. Its a bit of a shame since its influence over efficiency is way too big imo, but that's just me speaking here! :)
This is the case for the first 3 rounds only. For the remaining rounds, efficiency plays a much bigger part.

MadMatt
MadMatt
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Joined: 08 Jan 2011, 16:04

Re: Khamsin Virtual Racecar Challenge 2015

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cdsavage wrote:
MadMatt wrote:Downforce is really the number 1 thing, then. Its a bit of a shame since its influence over efficiency is way too big imo, but that's just me speaking here! :)
This is the case for the first 3 rounds only. For the remaining rounds, efficiency plays a much bigger part.
Yes I know that, its just secretly I wished efficiency was more decisive. At least we will see time-attack cars, it'll be fun!

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machin
162
Joined: 25 Nov 2008, 14:45

Re: Khamsin Virtual Racecar Challenge 2015

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It is worth remembering that if two cars have the same or similar Cl.A then the car with the lower Cd.A will still be quicker....

I'm excited to see what you guys come up with and what sort of aero coefficients you achieve!
COMPETITION CAR ENGINEERING -Home of VIRTUAL STOPWATCH

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machin
162
Joined: 25 Nov 2008, 14:45

Re: Khamsin Virtual Racecar Challenge 2015

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Hi guys, I've made a very small addition to Virtual Stopwatch... now there are a couple of extra lines at the bottom that tell you what the effect is on laptime if you have 20% more downforce & drag (i.e. your efficiency stays the same), or if you have 20% less downforce & drag.

Image

This will become more useful when we switch from the high downforce tracks to the low/medium downforce tracks half way through the season; it'll help you dial in your set-up for those tracks. For now you should all find that more downforce is better (i.e. more downforce = a negative time difference).
COMPETITION CAR ENGINEERING -Home of VIRTUAL STOPWATCH

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CAEdevice
48
Joined: 09 Jan 2014, 15:33
Location: Erba, Italy

Re: Khamsin Virtual Racecar Challenge 2015

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Thanks machin, exactly the difference I guess between my car and the winner of the first race :)

MadMatt
MadMatt
125
Joined: 08 Jan 2011, 16:04

Re: Khamsin Virtual Racecar Challenge 2015

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Ok so I managed to make my car legal (was way harder than I thought, that last rule change on cooling inlet really got me thinking), but here is also a small teaser for you, the car will be shown the 27th of this month (I will post this on my blog as well, and this date will match an empty time space I have on it, hence the small delay). I was able to run a CFD simulation with OCCFD, and I should at least be in the ballpark :D

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My pictures are not that good, they are taken straight from CAD, and I am no 3dsmax specialist unfortunately.

:)

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CAEdevice
48
Joined: 09 Jan 2014, 15:33
Location: Erba, Italy

Re: Khamsin Virtual Racecar Challenge 2015

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Good job! Your rear wing is identical to mine, but I thinking about a central support.

MadMatt
MadMatt
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Joined: 08 Jan 2011, 16:04

Re: Khamsin Virtual Racecar Challenge 2015

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CAEdevice wrote:Good job! Your rear wing is identical to mine, but I thinking about a central support.
Rather than end plates or in addition to end plates?

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CAEdevice
48
Joined: 09 Jan 2014, 15:33
Location: Erba, Italy

Re: Khamsin Virtual Racecar Challenge 2015

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with small endplates