Khamsin Virtual Racecar challenge 2013 (CFD model racing)

[astracrazy]

it doesn't matter mate if you don't know

learn sketchup first, enter this championship (you've got plenty of time it officially starts next season) and then learn about your car from the results you get. If you want advice, start up your own thread about your car and you'll get help. We arn't all as clued up as you might think. If you can get hold of some cfd programs that will obviously help you more

there was a guy on here the other day, he made a thread about starting up. Why don't you find it (was in this section) and start up with him so you both learn together?

[Markus]

Thanks for the suggestion.

[variante]

hey guys, i think i will join your championship, and if i'll find enough time, i'll be racing in the test race too. However i need a couple of clarifications:

1) are exhaust gases taken in consideration in your CFD analisys (if yes, which flow rate... max, average...?) ?
2) what about the rake of the car? Can we choose the exact amount of degrees despite not having wheels and suspensions?
3) will those blanked off areas be "unblocked" during the simulation (i'm asking because i read unclear things about this point)

[astracrazy]

hey. Don't worry i won't make the test either

1) no its not, not next season (the first season) any way. (I did suggest even tighter rules on the exhausts to prevent people wasting time trying to do ala mclaren or red bull - people will waste there time the way i see it anyway)

2) i think its set level - not 100% though i'm just going by the fact that the suspension is fixed and added to the model on simulation (although we should be getting it for ourselves for testing - we just won't send the car with it)

3) no they won't be - 99% sure. They want to be able to quickly check the sizes are within the rules and it will get extra complicated taking into account internal aerodynamics.

[machin]

I'm not involved on the CFD side, but I think AstraCrazy's answers are correct. I know the guys are a bit busy at the moment woth personal stuff, but I'm sure one of them will be along shortly to amswer the questions with definitive answers.

Probably best to submit your entry and get hold of the the welcome pack and start doing the basics on your models... Refinements to your models can come later.

[N12ck]

hey guys, i think i will join your championship, and if i'll find enough time, i'll be racing in the test race too. However i need a couple of clarifications:

1) are exhaust gases taken in consideration in your CFD analisys (if yes, which flow rate... max, average...?) ?
2) what about the rake of the car? Can we choose the exact amount of degrees despite not having wheels and suspensions?
3) will those blanked off areas be "unblocked" during the simulation (i'm asking because i read unclear things about this point)

yes Rich, I can answer,

1) No, we dont want to over complicate anything until it all gets going
2) No rake, must be level/ conform to regulation boxes supplied
3) No, as within sketchup, when you make a face it is infinitely thin, so our worry was that people wouldn't make a solid model on the internals as they have done with the externals, so this could cause problems for CFD, (a dimensionless face) so to combat this, Hibou Scientific Software judges the external aerodynamics with the CFD.

[astracrazy]

i know your busy with other things so I'm not putting pressure on you. Have you done the suspension models yet?

[N12ck]

i know your busy with other things so I'm not putting pressure on you. Have you done the suspension models yet?

I have been at uni for a few days now and I have a few free hours tomorrow so I will finish them then, I hope the explanation about infinite surfaces made sense?

[astracrazy]

no worries mate. Does the drive shaft come with it 2? silly question perhaps but would make sense.

regarding the 3 questions above? ye makes sense

perhaps you should add a questions and answers page to the website for questions like this being asked? I could come up with some q & a and message you to save time (like things answered here) ive also got other things that people might ask that could be worth answering

[RicME85]

I have a question regarding the supplied tub.
I changed the orientation of it and lined it up with previous models and things do not match. If you measure it up against previous cars and the Formula Sketch boundaries things like the plank at the splitter end are longer on the KVRC model.
Is there a simple reason for this that is eluding my brain like wheelbase etc or is it that there are some dodgy measurements going on somewhere.

I came across this because I was trying to get the KVRC supplied models on the same axis and in the same location as all my previous Formula Sketch drawings so that I could chop and change components to get the desired outcome.

I hope you understand my drivel, the medication makes it hard to understand simple things and also to put things down into words.

[astracrazy]

my model is a different axis to the supplied tub too

Sound like the supplied tub is just a diff wheelbase. It won't (shouldn't) make any difference as long as you are within the f1 regs

[N12ck]

Hi, yes the tub has a different wheelbase ours is 3400, fsketches being 3330mm if I remember correctly, also if you read the front wing regulations you will realise that the supplied regulations are correct and your old ones you used in the last competition you entered in we're incorrect

[stez90]

About "standard" suspensions, I'm working on a lower tub (i.e. like mclaren, without the step on the nose) so I think my front suspensions mount points are lower than the provided tub..

N12ck will you post your CFD results?

[N12ck]

About "standard" suspensions, I'm working on a lower tub (i.e. like mclaren, without the step on the nose) so I think my front suspensions mount points are lower than the provided tub..

N12ck will you post your CFD results?

Hi,

We will post the coefficients, but you will not have access to the visualiser files of my car, also, the standard suspension will fit, I am working on a simpler version which can be distributed to teams,

[astracrazy]

nick, do you know the conditions yet? I take it the models will be tested stationary i.e rotating wheels and moving floor won't be used?