Khamsin Virtual Racecar Challenge 2014

[CAEdevice]

Chris:
I don't know about this side of it really (in terms of what the portal gives you). I've got mine sent to me so i will have a play when i get home and see what i get

Matteo:
I found this last year, it never does. The rotating wheels change things no end.

Yes, rotating wheels are important (I run some simulation including this effect, but not with the final geometry). I also think that the turbulence parameters are important: I've no experience in CFD so I probably used not realistic values. I have to calibrate my wind tunnel

[CAEdevice]

The size of the zip file in the email I got was about 20mb. Is yours bigger?

About 1gb...

[julien.decharentenay]

@cdsavage There has been an issue with your file. I am about to restart the simulation. I am actually surprised that you received an email - I need to check this issue as well. Sorry for the late action: I was away for the week-end.

@CAEdevice Turbulence model is k-omega SST. Let me know if you need more details such as turbulence coefficients. At least you have a benchmark now to calibrate your simulations.

[CAEdevice]

@CAEdevice Turbulence model is k-omega SST. Let me know if you need more details such as turbulence coefficients. At least you have a benchmark now to calibrate your simulations.

Thank you, the turbulence parameters would be usefull, in the meanwhile (maybe for the third race) I hope to find some time to install Khamsin and OpenFoam on a different (linux) workstation so I can simulate the official CFD engine.
I see the videos about Khamsin and it is very promising, I've been quite lazy untill know only because I don't like SketchUp at all... have you ever thought about a SolidWorks or SpaceClaim plugin?

[astracrazy]

@cdsavage: Your results should all be ok now, i've processed them our end

[astracrazy]

Just an update/clarification:

We are on schedule for releasing the results Sunday. I anticipate the results will be released in two sections. More to come...

Just to clarify the process in terms of your submission. It works in two stages;

Stage 1: The Thursday PM deadline. This is classed as submission 1. If you car is legal or you receive what we call a warning e-mail, which outlines your car is legal but there are 1 or 2 minor things which won't effect the results but must be changed for the next race, you do not have to do anything else. This submission will be used and you will receive an e-mail any time up to Sunday PM.

Stage 2: If your car is illegal you will receive an e-mail telling you what is illegal Sunday PM and you are given until Tuesday PM to re-submit a legal design. You are only permitted to change what is illegal about the car and nothing else. This submission will be used legal or not (10 sec penalty if it is illegal). You will be e-mailed confirming either way. If you make 'other' changes your original submission is used and you will get a penalty. You can choose not to re-submit and in such as case your first submission is used with a 10 sec penalty (it would be handy to try and let me know if this is the case so we can process your car)

If your car passes at stage 1 you can not submit another design (even if you get a warning e-mail). Stage 2 is purely for illegal cars.

For the future races all e-mails will be sent at the same time instead of legal being sent as I go and illegal Sunday PM.

[julien.decharentenay]

Thanks a lot to @cdsavage for doing an in-depth review of the provided results.

There are a couple of issues that (hopefully) should be solved in the next couple of hours/days:
- Downforce and drag distribution reported on the summary table are incorrect - they are not a distribution as such;
- CoP - to be confirmed.

The turbulence parameters are as follows:

Selecting RAS turbulence model kOmegaSST
kOmegaSSTCoeffs
{
alphaK1 0.85034;
alphaK2 1;
alphaOmega1 0.5;
alphaOmega2 0.85616;
gamma1 0.5532;
gamma2 0.4403;
beta1 0.075;
beta2 0.0828;
betaStar 0.09;
a1 0.31;
b1 1;
c1 10;
F3 false;
}

[CAEdevice]

That is good news... now I know why I could not calibrate my model
Thanks for the turbulence parameters!

PS: Can you confirm that the total resultant downforce and drag are correct?

[astracrazy]

.......such a tease

***

Just to let everyone know all cars have now been processed and we are just waiting for 1 or 2 results.

I was hoping someone might pick up on the watch now bit. We got something to present the results in a better way. I'm happy with it, and I think Julien is too (and he deserves a lot of credit). Looking forward to getting everyones feedback

[CAEdevice]

Can't wait to see the cars that was not announced on the forum, and also the other car in the "legal" version (mine inlcuded).

I think that Luke and Julien did a great job: the only thing that I would improve is the "presence" of the teams on the forum (to chat about our solutions is the most funny and interesting thing).

[astracrazy]

i agree about the forum part, we have tried to encourage it by putting it on the website and in the joining e-mails. I guess some just aren't as keen.

to update:

All the results are in, Julien is just checking the final few COP's are correct (after the minor issue we had).

[julien.decharentenay]

Just sending a quick confirmation that the CoP results have been updated and that the drag and downforce distribution graphs should be correct as well.

Also: I will be updating the back-end to CFD Apps next Monday - I tried very hard to not touch it while the race is on. The update should improve turn-around time for the generation of openFoam cases and add a couple of feature, but there should be no change in simulation process (i.e same parameters and the like). So the results should be the same. There will probably be some issues for a couple of days (let me know so I can fix them asap).

[CAEdevice]

A question for all the KVRC competitors that (like me) are lost in CFD simulations
Is it possible that rear (rotating) wheels generate donwforce (and not lift) at 100mph?

[CAEdevice]

Congratulations to the CSR team, winner of the first race (Monaco) and to Variante and JJR that were on the podium. I look forward to the press conference after the awards ceremony!

I am satisfied with the performance of my team (CAEdevice): the result is exactly what I expected seeing the preview of the first car classified, and even "numerically" the result reflects the values ​​of "drag" and "downforce" of my simulation. Only the COP I is out of control: I have to work on my wind tunnel

Thanks to Julien and Luke: I've never had such fun spending time with CAD and CFD at my workstation

[astracrazy]

Glad your enjoying yourself.

I think everyone done well considering this year is hard as we have a whole rule book. Looking forward to seeing what everyone comes up with for the next race.

Once again, please remember to send me some pictures of your cars, i want to try and get as many as i can on the site.

What is the opinion of the race visual? did you all look at that first? How could it be improved?