Khamsin Virtual Racecar Challenge 2015

[chuckdanny]

A wing with a concave diffuser exist, though i doubt it's stable enough for passenger plane, it works for small scale model
It's called Vortex Cell Wing.
That's interesting
http://ltces.dem.ist.utl.pt/lxlaser/lxl ... 11.3_4.pdf

[variante]

Interesting, indeed!

That concept was used on a Jordan F1 from the 90s, on its diffuser's throath. However that doesn't increase extraction: it just keeps the flow attached despite the violent transition.
Here it is:


I also gave it a try myself on a radiator diffuser (on its lower surfaces):


(However, when i talked about concave wings, i didn't mean to mention vortices: just a greater extraction volume)

[chuckdanny]

I didn't know this jordan experiment, great!
Maybe in getting the vortex rotating the other way around would improve extraction with a vane feeding the cavity underneath

[julien.decharentenay]

It is great to see these technical discussions. Just wanted to let you know that I am running some final tests on a new version of OCCFD for use in the next race. The mesh settings are altered alongside the calculation of the CoP.

[CAEdevice]

Thank you for the update Julien. Wich changes are you testing?

[etsmc]

Would be interesting to see some of the slower cars front and rear sliced like the top 3, might prompt a bit of discussion on the difference and how they can improve.

[RicME85]

I agree.

[CAEdevice]

Hi, is there any news about the side impact template rule?

[julien.decharentenay]

Thank you for the update Julien. Wich changes are you testing?

In a nutshell:
- OCCFD had a system in place to generate a refining area based on the gradient of the coarser solution. This system seems to create some issues. It is replaced with a straight-forward mesh refinement region around the car (which is not great, but is more robust);
- COP: I am replacing the calculation based on the moment with a more simple calculation done in ParaView. It is more straightforward and simple, but has a couple of drawback: it only account for pressure induced downforce, and is only based on the last time-step (no time averaging).

At the moment my last minute testing has uncovered an issue when doing the solution mapping. I can't understand where it is coming from and is stopping me from moving forward. I got the feeling of bagging my head against a wall...

[CAEdevice]

Be careful with your head! The changes are in the right direction. The COP computing based on the last timestep is ok, the simulation seemed to converge much earlier.

The dynamic mesher is great and smart for analysts, but for designers a more robust one is ok.

[cdsavage]

A few updates/reminders heading into round 2:

• Full car checks were done prior to the entry deadline for round 1 because this is a brand new rulebook. Everyone seems to have a pretty good grasp of the rulebook now, so for round 2 onwards we won't be doing the pre-deadline checks, and we'll be following the same procedure as 2014 - the first official submission is checked, and if illegal, there is a chance to submit a second entry with the issues corrected. With that said, I'm happy to answer any questions about specific concepts/rules at any time through PMs or email.
• For anyone whose round 1 entry had issues marked as 'minor' in the legality check email, remember to correct these issues for your round 2 entry. This includes the entries where a second submission wasn't necessary.
• The rulebook PDF has been updated with the minor changes mentioned earlier.

Hi, is there any news about the side impact template rule?

Definitely won't be changing for round 2 or round 3.

[RicME85]

Have the result been updated with the updated figures from my car?

[cdsavage]

Have the result been updated with the updated figures from my car?

http://www.khamsinvirtualracecarchallen ... 15/results - you're now 8th.

[julien.decharentenay]

I finally got around my issue prior to getting the wall down... It was easy to fix, once the problem was identified. I am running what I hopping to be a last test and then the new version comes out...

[LuPi]

Mitakuye Oasin,

I've recently signed up team DruiDtek, anyone want to join???

Found the challenge on this site recently after branching out to many sites to learn more for my engine build.
From HBA, so I know a little aerodynamics.

Thx for having me,

LuPi