Khamsin Virtual Racecar Challenge 2014

[RicME85]

OK, slightly different format to last years charts:-

Cd.A along the bottom and lap time on the right. The lap times assume you have COP=1.83m behind the front axle. The shaded area represents Cl.A ranging from 2.8 along the lower edge (light blue) and 2.0 along the upper edge (dark blue).

http://www.competition-car-engineering. ... oGP_14.jpg

You can see from the fact that the lines of equal Cl.A are very flat that drag has little effect on lap time around Monaco: so you should be concentrating on achieving high downforce.

Just used the spreadsheet Julien provided to work out drag etc and got a figure of -1.32 for Cl.A

[julien.decharentenay]

Is anyone else getting "Error when retrieving case information details from server" when trying to use the portal? I can see it uploading if I watch network activity on my PC, but then I get that error.

Apologies. Issue should be fixed now.

[julien.decharentenay]

Just used the spreadsheet Julien provided to work out drag etc and got a figure of -1.32 for Cl.A

Cl.A uses the third component of the force. A positive force indicates lift and negative force indicates downforce. Traditionally Cl denotes a lift coefficient - this is going back to the aeronautic industry. So a negative Cl would indicate downforce.

My aerospace background is clashing with the automotive focus of the competition...

[RicME85]

Ok, so in that case should I be looking to between -2.0 and -2.8 then rather than +2.0 and +2.8?
Im just a little confused by Machin's graph as it shows positive figures.

Btw Julien, after asking you about viewing wing tip vortices and you suggesting trial and error with the x,y,z figures in Paraview I figured out you can move a crosshair to the desired point instead if Stream is selected in the viewer on the left.

Having issues with the supplied tunnel though, when I have tried to run a simulation the CMD window disappears after a matter of minutes, is this a case of my PC throwing a hissy fit at the mesh size or is it something I am doing with regards to setting things up?
When I have imported my car into the tunnel I am unable to check the boundary conditions.

[CAEdevice]

I'm going to upload my car.
Not completely satisfied by the result, but I'll be out of office in the next days so I'll have time just to fix small details in order to respect the rules if needed.

Edit:
it seems to be a problem: I can't see any form to fill in ("the file is missing" is the only message I read after "Fill in the form below to submit your design:").

[RicME85]

Seems to be an issue with the link in the HTML or something as the page cant find the form.

[machin]

Ok, so in that case should I be looking to between -2.0 and -2.8 then rather than +2.0 and +2.8?
Im just a little confused by Machin's graph as it shows positive figures.

Yeah, It depends on what convention you are using... you want as high a value as possible in terms of downforce (downward force) as you can. Once we've done the first round I can ensure the charts cover the range of Cl.A value's you guys are actually achieving. Although from the Monaco chart the "take-home" message is that more downforce is good and drag isn't that bad; the numbers themselves shouldn't be that critical to your design process.

Cheers,

[RicME85]

thanks for clearing that up

[astracrazy]

Bare with me on the submission page, i will see if i can see the problem now

UPDATE:
I have checked this and it seems to be a issue with publishing the script. When i log in with my google account I can see the form. Julien will need to change this as I can't - I will e-mail him now and report this issue.

[julien.decharentenay]

Bare with me on the submission page, i will see if i can see the problem now

UPDATE:
I have checked this and it seems to be a issue with publishing the script. When i log in with my google account I can see the form. Julien will need to change this as I can't - I will e-mail him now and report this issue.

I think I fixed it on the way home. I would love to have confirmation that it is all clear. @CAEDevice, we(I) have received confirmation that you have submitted your design. Well done and thanks for being early...

[CAEdevice]

Bare with me on the submission page, i will see if i can see the problem now

UPDATE:
I have checked this and it seems to be a issue with publishing the script. When i log in with my google account I can see the form. Julien will need to change this as I can't - I will e-mail him now and report this issue.

I think I fixed it on the way home. I would love to have confirmation that it is all clear. @CAEDevice, we(I) have received confirmation that you have submitted your design. Well done and thanks for being early...

I confirm that everything worked well this time! Thanks to you all.

[astracrazy]

Important

I didn't realise the old group names were still in the rule book. When you submit, please make sure you use the following group names as described by Julien

Wheel-Back-Right
Wheel-Back-Left
Wheel-Front-Right
Wheel-Front-Left
Body
Rear-Wing
Front-Wing

If you have already submitted and used the old names, I have already contacted you. I'm awaiting Julien to let me know if these are still ok - I don't know how the groups are picked up by the portal. It might not matter.

Sorry it's my fault

Luke

[julien.decharentenay]

The portal has some level of flexibility. The group name as per the above post or as per the rule book should be fine. If you notice an issue when you receive the results, please let me know.

Issues to look out for are that are related to the naming convention:
- Smaller mesh on the front and rear wings;
- Wheel rotation;
- Location of reference point for the CoP.

Big thanks to all the teams for payment. It is great to see the commitment to this challenge.

[astracrazy]

a little reminder as well:

if you are sending your model in .skp format, please ensure the type is version 8. You do this under Save As, Save as Type, then select version 8 from the drop down. If it is in a higher version I can't open your model so it will be rejected and you will need to re-submit

[AratzH]

Good point! I failed to do that the first time!