Khamsin Virtual Racecar challenge 2013 (CFD model racing)

[astracrazy]

this may sound a silly question. I haven't got internet at home (can only connect computer to my phone and then use 3g) for the time being. Its slow and crap so but i can download things. Once khamsin is downloaded and installed does it still need an internet connection? or can it run offline. Might be a silly question but i don't know.

Im planning on doing a session tonight to get the V2 pack and khamsin lol

ps. if anyone gets a simulation to work, can they right a dummys how to guide? with settings etc

[machin]

When you run simulations on the car do you take into effect the centre of gravity?

Virtual Stopwatch (the program used to determine the lap times after the CFD is done) does use centre of gravity to determine load transfers during acceleration, deceleration and cornering... as per the real F1 rules we take the weight split at 46:54 front:rear, with a weight equivalent to minimum weight plus a bit of fuel... I forget what CG height I've put into the F1 car mathematical model we use, but it'll be somewhere around the wheel centreline height.

For more info on how Virtual Stopwatch works you can read on my website:

http://www.competition-car-engineering.com/Intro.htm

[julien.decharentenay]

Khamsin works offline. To have a complete working version of Khamsin, you will need to download the third party tools. The openFoam third party tool is quite large and I have had the download failing a few times. If you can try to get a good internet connection access for these downloads.

Another thing: if you are using the provided wind-tunnel, do check that the solver is "simpleFoam". If it is not, change to simpleFoam...

[julien.decharentenay]

When you run simulations on the car do you take into effect the centre of gravity?

The CFD evaluate the design aerodynamic performances (drag, downforce, center of application of downforce).

Virtual Stopwatch - to my understanding - uses the center of gravity alongside other parameters (including predicted aero forces). The center of gravity is fixed - not based on the car design.

[astracrazy]

do the third party tools download automatically, or do you get then option to download during install?

Thanks for your help

[cdsavage]

Looking at how the sidepods are regulated, there's nothing stopping you at the moment from having ridiculously tiny sidepods - imagine an inlet at the required size, with a sidepod that tapers back from that, ie from front-on none of the sidepod is visible outside of the profile of the inlet. The regs say that you can ground a car for that sort of unrealistic stuff, but where do you draw the line?

Maybe a regulation on cross-sectional area of the sidepod at a certain distance behind the inlet would help.

Also, will we be getting a copy of the wheels and suspension? We need the wheels at the very least to be able to judge the shape of the floor in front of the rear wheel.

[etsmc]

whats the exact issue with the floor in the V2 pack and what needs to be done to rectify it??

[astracrazy]

Looking at how the sidepods are regulated, there's nothing stopping you at the moment from having ridiculously tiny sidepods - imagine an inlet at the required size, with a sidepod that tapers back from that, ie from front-on none of the sidepod is visible outside of the profile of the inlet. The regs say that you can ground a car for that sort of unrealistic stuff, but where do you draw the line?

Maybe a regulation on cross-sectional area of the sidepod at a certain distance behind the inlet would help.

Also, will we be getting a copy of the wheels and suspension? We need the wheels at the very least to be able to judge the shape of the floor in front of the rear wheel.

I believe wheels and suspension is going to be sent out soon

regarding sidepods, perhaps a rule like that may well be needed. I guess we will have to wait and see if people take the p*ss or if theres arguments about it.

I think the rule of thumb it will be compared to current f1 cars, if its been done or is similar then its ok. I guess if you made a stupidly small sidepod, you'd need to prove you can fit radiators etc. in it. It will be pretty easy to look at a car and tell if its unrealistic and the person making it will know it is too

whats the exact issue with the floor in the V2 pack and what needs to be done to rectify it??

Its not just the floor. its the whole regs forward of the rear cockpit entry template. The problem was the measurements were made from the rear of the cockpit padding which means everything is too far forward by maybe 50mm (i haven't checked). Best thing to do its only do you car from airbox backwards for now or remeasure yourself. as soon as you know the difference you just need to move everything back by that much

[RicME85]

Decided to build my car from scratch. So far I have part of the monocoque designed but I have an issue with the head protection. Is the supplied tub correct? From a cockpit template I have downloaded from Google Warehouse and from looking at what is written on the FIA website

The rear 375mm of the cockpit’s side walls must rise upwards at an angle of at least 16 degrees

the supplied tub's protection starts too far back (only 319.4mm from the rear of the cockpit) and has a higher angle (51.1 degrees).


Green = The template I downloaded plus FIA website wording
Red = KVRC supplied tub

Im asking as I obviously want whatever I design to be legal but so far with the model I am being extremely anal and drawing parts to dimension and thickness and adding the whole car together with grouped parts, for example, my cockpit is separate to the head protection, the section bulkhead A to bulkhead B is another separate group. This will allow me to modify the car a lot easier down the line, the only problem is its creating a lot more work for me

[N12ck]

Hi, I have recently been in and out of hospital with a broken ankle, so please give me some time to go through and check the supplied tub

[RicME85]

Thats fine Nick, I know what its like to be in and out of hospital, life is so disrupted and then its hard to get back into the rhythm of things once home.

I have PM'ed amouzouris in the hope of getting an answer but he is so busy and has asked for the full wording on head protection in the regulations but Im finding it a nightmare to string together all the various bits of information

Your tube may well be correct, it might just come down to individual interpretation, Im not sure, just wanted to get it right first time is all

[N12ck]

may i refer you to page 73 in the regulations: http://www.fia.com/sites/default/files/ ... 111212.pdf



the floor was out by 100mm, but that has now been corrected

[Monster_Energy_F1]

Nick, any news regarding the message I sent you. Or was it just my computer?

[RicME85]

Nick, what plugin is that in the 2nd toolbar?

:edit:

Nvm, figured it out

[etsmc]

is the blade roll hoop at the maximum allowed height?? anything above that is outside the regulations?? not got the welcome pack on me to check..