Khamsin Virtual Racecar Challenge 2014

[astracrazy]

Sorry, Julien who deals with the cfd side is away at the moment. Can you elaborate more on what you mean and i'll try to help

[CAEdevice]

ok, I have 2 other questions:

1 - it seems that in 2013 season the CFD simulation was done without considering the helmet, Am i right? Is there a reason? I thuink that the helmet could influence the results

2 - it would be intersesting to define e minimum (average) pressure the inlet surfaces: their projection could be "shadowed" by other geometry (a very low average pressure would be irrealistic). In practice it would be convenient to put the inlets the most far from the centerline, even if the front wheels could reduce the real inlet flow.
The best thing should be to model the heat exchanger as "assigned part and to cumpute the pressure on it, including in the car shapes at least the internal flow that reaches the exchanger.

[cdsavage]

1) Yes it will influence the results, but there is no need to be able to make direct comparisons between 2013 cars and 2014 cars.

2) The rules state that there must be nothing other than the front wheels/suspension obscuring the sidepod intakes when viewed from the front. There is nothing stopping you from moving the intakes outboard as long as it complies with this. The decision is not mine to make but my opinion is that modeling internal flows is too complex for the scope of the competition, and in any case it would require a whole extra set of rules etc for little benefit.

[astracrazy]

cd has really answered it. The inlets/outlets need to be closed off to make a water tight volume.

The problem with internal aero is its far more complex.I think if your going to do it then it needs to be done properly and that is far more than than what is needed for this. It would be more than just flow internally, you would need to take into account heat transfer etc.

If we are to add anything extra next year than i would like to look at the possibility for exhaust flow. But that is a conversation for another day and I don't know if that's possible.

[CAEdevice]

Thank you all for your answers.

1) OK, but should I consider the helmet in 2014 car shape or not (i'm modeling the engine inlet just now )?
2) OK, I was not clear: I didn't mean direct shadow but also indirect shadows caused by depression regions (the answer was clear anyway)

[astracrazy]

Yes. It will be used in the simulation.

Also make sure that when you do your cockpit template the helmet is sitting in this (see example in welcome pack). We are not having the gaps like in real f1 (between helmet and edge of template)

[CAEdevice]

What about rear view mirrors?

[cdsavage]

There is a section in the rules PDF for mirrors (yes they need to be included).

[CAEdevice]

Sorry to bother you, but I've some difficulties in interpreting the PDF.
This time I have a doubt about the minimum thickness of the components of the front (and rear) wing.
The minimum thickness rule (10mm) should be applied to all components (flaps included)?
Thanks
Matteo

[Bazza]

Quick request - would anybody be able to upload a copy of the current draft file (from the first post) as a OBJ file?

I'm sorta contemplating "Pulling A Honda" and not officially competing this year, just doing external development, then maybe entering next year. That, or spend the year working on the car, give it to a team and watch them walk away with the championship next year (a.k.a "Pulling A Honda").

[astracrazy]

Im not sure what your on about doing to be fair. If you want the files then please join or create your own

[Bazza]

I would possibly be joining next year, and I wanted to spend this year testing, trying things out, and so on. Outside the competition - not entered in the races and events or anything. Like I said, similar to what Honda is doing this year with their engines (spending time in development, to hopefully hit the ground running next year).

[cdsavage]

When you download the latest version of Sketchup it gives you 8 hours to use the pro features, which I think includes OBJ export.

Are we any closer to having the mesh resolution decided? I was going to suggest that we use a boundary layer + trim mesh but Im not sure if the boundary layer option in Khamsin works correctly.

[CAEdevice]

Sorry to bother you agian, nuit it's the first time I'm planning to take part to the contest, so I have many doubts about the rules.
I'm confused about this piont:

K8.2 (Sidepod) (Light Yellow)
The volume in the following defined areas must form a smooth, continuous surface
with a minimum radius of curvature of 75mm:
a) between CC and 450mm forward of it, more than 350mm from the car centre line
and more than 100mm above the reference plane
b) between CC and 300mm rearward of it, more than 125mm from car centre line and
more than 100mm above the reference plane
c) between 300mm rearward of CC and 50mm forward of the rear wheel centre line,
more than 25mm from car centre line and 100mm above the reference plane

The minimum radius (75mm) is a general value (curvature) or only the curvature of the projection of the sidepod on the ground (or on the reference plane)?

Here are two different sidepod design: the projection on the gorund is the same (and control sections are extended enough: 120000mm2 and 50000mm2) but the secondo has 25mm rounds insetad of 75mm.

75mm rounds ( http://www.caedevice.net/SERVER/Khamsin/R75.jpg )


25mm rounds ( http://www.caedevice.net/SERVER/Khamsin/R25.jpg )

[cdsavage]

Technically the rule in the full F1 regs states that the curvature of a section with the XZ plane (ie, looking from the front) must not have any curvature less than 75mm - something like this:



This applies to all the bodywork in the R75 volume. I think in the latest guide file it isnt in a named group, but in the version I have its the yellow boxes around the sidepods.

In practice you dont need to make curvature measurements or anything like that, you just need to follow the 'intent' of the rule. According to the full rule, your first example would be legal while your second one wouldn't be, but both would probably be acceptable for the competition. I guess ask astracrazy for his interpretation since I think he will be judging.