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Re: Khamsin Virtual Racecar Challenge 2014
Posted: 14 Feb 2014, 13:42
by julien.decharentenay
Thanks Richard for reporting on our discussion. Dan, your file should have arrived (apologies for the very long delay...). I am still quite actively developing it and so the delivery is a bit hectic...
As mentioned, as long as you have an openFoam distribution (Linux, Windows or Mac or any other), you should be able to run simulations. Khamsin is an extension to SketchUp and only Windows is supported. Although there is a functionality to send the simulation to a remote Linux computer.
The portal returns an archive. Just download it on whichever platform you have and type the "right" commands. Note: the portal case will generate a mesh of approximately 2.5 Millions to 3 Millions cells, so make sure that your computer is able to handle it - mine will not...
The second and third hangout (referring to Luke email to the registered participants) will be solely focused on getting participants up-to-scratch with running CFD simulations on their own computer. I would like them to be hands-on sessions so that any installation, setup, running or post-processing issues can be ironed out.
Re: Khamsin Virtual Racecar Challenge 2014
Posted: 14 Feb 2014, 13:47
by julien.decharentenay
With Luke's permission, I altered one of his SketchUp model from last year to show how to group, orient and position the car elements as described in the KVRC rules. You can download the model at
http://www.khamsinvirtualracecarchallenge.com/do (file LBRacing 2013 v2.skp).
If using STL files, ensure that the name of the solid (in the STL file) are similar to the ones in the SketchUp file or as described in the KVRC rules. More on the subject in the first Hangout.
Re the rear wings: if your rear wings side plates have small penetrations. You are advised to group these penetration and use a group name (solid name for STL files) that uses the keyword "wing", such as "rear-wing-penetrations".
Re: Khamsin Virtual Racecar Challenge 2014
Posted: 14 Feb 2014, 13:56
by CAEdevice
Sorry Julien, I'm not sure about what you mean with "rear-wing-penetrations". It has to do with minimum thickness of the wings?
Re: Khamsin Virtual Racecar Challenge 2014
Posted: 14 Feb 2014, 15:37
by astracrazy
in the endplates some teams have 'gills' or slots in the endplates (see most f1 cars for this example).
I'd actually suggest in the interest of simplicity and keeping it the same across the board, make the endplates part of the rear wing group anyway - i'll confirm with Julien first
Re: Khamsin Virtual Racecar Challenge 2014
Posted: 14 Feb 2014, 15:46
by CAEdevice
astracrazy wrote:in the endplates some teams have 'gills' or slots in the endplates (see most f1 cars for this example).
I'd actually suggest in the interest of simplicity and keeping it the same across the board, make the endplates part of the rear wing group anyway - i'll confirm with Julien first
Thank you! I'm not planning to insert such slots at the moment
Re: Khamsin Virtual Racecar Challenge 2014
Posted: 14 Feb 2014, 17:23
by RicME85
I ran a simulation last night via Khamsin and had the endplates in the same group.
Re: Khamsin Virtual Racecar Challenge 2014
Posted: 15 Feb 2014, 08:07
by julien.decharentenay
Please ignore the following from my earlier post:
julien.decharentenay wrote:if your rear wings side plates have small penetrations. You are advised to group these penetration and use a group name (solid name for STL files) that uses the keyword "wing", such as "rear-wing-penetrations".
Ensure that the rear wing side plates (or end plates) are part of the "rear wing" group. I will update the SketchUp file on the KVRC download section accordingly.
Re: Khamsin Virtual Racecar Challenge 2014
Posted: 15 Feb 2014, 08:16
by julien.decharentenay
I have sent the invoices earlier today. Let me know if you have not received yours (or if I made a mistake). They can be cancelled or amended as required. I tried to get people's country when I knew it.
We have just added an account page on the website
http://www.khamsinvirtualracecarchallen ... 4/accounts where we will report on collected and spent money for transparency.
Re: Khamsin Virtual Racecar Challenge 2014
Posted: 15 Feb 2014, 18:42
by CAEdevice
Invoice recevied and payment just done! Thank you!
Re: Khamsin Virtual Racecar Challenge 2014
Posted: 18 Feb 2014, 11:30
by CAEdevice
Hi Luke, I was wondering if that profile could be considered legal (the arrow points to and edge with thickness smaller than 10mm). If legal: can it cause any iusse during meshing?

Re: Khamsin Virtual Racecar Challenge 2014
Posted: 18 Feb 2014, 11:40
by CAEdevice
A question about the Virtual Stopwatch way to simulate new power units.
Wich of theese three models will be simulated (for a lap that lasts about 90s)?
1) Avergage maximum power. Es. (500cv * 90s + 150cv* 30s)/ (90s +30s)
2) Internal combustion power for the whole lap + Electric power only for the allowable seconds (I can't remember, may be about 30s: the question is how to distribute that time). Es. 500cv for the first 60s, than 500cv+ 150cv for the remaining 30s.
3) Only internal combustion power (500cv) for the whole lap.
PS: I asked because I'm working on setups considering the maximum speed that I need to reach for each circuit
Re: Khamsin Virtual Racecar Challenge 2014
Posted: 18 Feb 2014, 11:46
by astracrazy
Yes that is legal, there is no rule that specifies a minimum thickness in the area. as it is face on it shouldn't cause mesh problems. The mesh problems are usually gaps getting covered over.
I don't think that the new power units are used. I'd imagine there isn't enough data available on them yet.
Re: Khamsin Virtual Racecar Challenge 2014
Posted: 18 Feb 2014, 12:22
by CAEdevice
Thank you! Yes, to use old data for the engine would be a good idea.
In that case, what is the maximum power?
Re: Khamsin Virtual Racecar Challenge 2014
Posted: 18 Feb 2014, 12:46
by astracrazy
i'll be honest i've had nothing to do with virtual stopwatch yet.
pm Machin
http://www.f1technical.net/forum/member ... ile&u=6715 its his program so he will be able to give you everything you need
Re: Khamsin Virtual Racecar Challenge 2014
Posted: 18 Feb 2014, 13:14
by cdsavage
Just to confirm - using these files:
khamsin-v1.1-09-kvrc2014.rbz
KVRC2014-Khamsin Model.skp
I can import my car parts and locally generate an identical openfoam case to what the portal would output?