Khamsin Virtual Racecar Challenge 2015

[Gridiot]

On my side, last round was my first shot, and there's still no chance at the moment that I can do CFD development between rounds. So official races are actually the entirety of my development process. Therefore, I have probably more performance to get by building on my previous run and see what could be improved based on the CFD analysis in order to optimize my car, rather than starting again from scratch every time. So I didn't try to go for a full low drag spec and I just tried to address some issues from previous round.

Anyway, I didn't have the highest drag / downforce setup last round, and we're only speaking about Magny-Cours, not Monza, Le Mans or Indianapolis... so I don't feel necessary to go for extreme low drag spec. But all of this depends on the simulation, so let's wait and see. I may have to reconsider.

What is sure is that my car still has significant potential to unlock and I'll probably need a few more attempts to reach a reasonable baseline. Let's hope I can got this by the end of the season!

PS: Congratulation to everyone for last round results and also new designs for this one!

[JJR]

Nice!
From ultra low downforce to middle-high downforce configurations.

[julien.decharentenay]

Hello. Thanks for participating in the race #4. In a nutshell, I am running late with the CFD simulations. I had a big work presentation this week, which went fine...

I am having some issues with Amazon at the moment. I have been using the us-east region since the beginning, which worked fine from Australia. But here in the uk, the connection is very unreliable... I will have to change to a more local region for the next races. But for some reason I can start and retrieve simulation (slowly), but can't get access to the account console...

I will keep you updated on where things stand, but expect a little delay...

[RicME85]

Has been issues with the Virginia sever. I ran some tests the other day but was unable to retrieve the results due to it. Went on the support site and it showed issues and a number of people posting about it.

[graham.reeds]

Has anyone written any tutorials about designing a car for this series? Looking a car design tutorials for SketchUp take photos or scanned in line drawings. I am having trouble getting anything other than rectangular blocks. I know what I want but not particularly adept at getting it. How much practice have you guys had at using sketchup prior to entering these races? What plugins do you use?

[RicME85]

Prior to KVRC I had minimal as there was a competition before it but that was judged by eye rather than CFD but essentially I am self taught.
The best thing you can do is sign up to Sketchucation and get their store plugin so you can grab some plugins to make your life easier.
Curviloft is a must, it makes life so much easier.
I watched a lot of Youtube videos to learn how to use various built in features and added plugins.
Start with the supplied parts (the fenders, nose and cockpit) and add the bodywork between to get a base then go from there.

[julien.decharentenay]

You do not have to limit yourself to SketchUp. If you are familiar with other 3D CAD package, then you should be able to use them (the submission is done in STL format now). Once proficient with the CAD package, it is on-to aerodynamic design and airfoil - there are quite a few resources on this such as http://www.consultkeithyoung.com/conten ... n-resource - and modelling to test the solutions...

On the race #4 front, we have CFD results for 6 of the 9 submitted design with simulations running at the moment (fingers crossed). Amazon is better in terms of download speed, but I seem to have lost access to my console (I can still use the API). And the Amazon support has not been helpful (in short I don't seem to have the right email address, and they can't let me know what is the right email address)...

[RicME85]

[machin]

On my side, last round was my first shot, and there's still no chance at the moment that I can do CFD development between rounds. So official races are actually the entirety of my development process.

In a way it is nice to hear that happening, and exactly why we selected the circuits we did and the order in which we do them; so that you can develop race by race.

I'm intrigued to see how the "low drag" designs work... At the moment I remain to be convinced... If you can design a low drag, balanced, car without wings then it theoretically seems relatively "easy" to also add a low incidence high aspect ratio wing at both ends... As long as each wing is over 5:1 L:D then you'll be adding performance to the car by doing so (5:1 being the "cut-off" for these rounds)... But time will tell...

[RicME85]

Yeah I dont think I will do very well this time out.
My car for round 3 had the following results:

My car for round 4:

[CAEdevice]

Yeah I dont think I will do very well this time out.
My car for round 3 had the following results:
http://i.imgur.com/OY4FSGS.png
My car for round 4:
http://i.imgur.com/iqaLd8K.png

Thank you for sharing. I don't have received the official results, but I expect to have about 1850N of drag!

[TalnoRacing]

In the spirit of sharing, here is a quick comparison between my entries for rounds #3 & #4:

I did not expect to see such a low drag figure for Round #4:


considering the how much drag the entry for Round #3 had:


Pressure distribution from the top:
Round #3:


Round #4:


and the bottom:
Round #3:


Round 4:


I plan on creating a dedicated thread shortly.

[JJR]

Congratulation TalnoRacing!

More downforce and less drag than in 3rd round. Massive improvement!

[CAEdevice]

Very good job TalnoRacing! Which is the function of the inlets (or outlets?) in front of the rear wheels, just above the floor?

[TalnoRacing]

@JJR - thank you for the compliment.

@CAEDevice - those are engine exhaust outlets. Chris indicated that internal space for a realistic exhaust is very limited, so I will have to change it for Round #5.