Khamsin Virtual Racecar Challenge 2015

[MadMatt]

I still think that you can go with something like the latest group C cars (Jag' XJR14) to balance the diffuser, isn't it?

I am also covering wheels at the moment, but I will also have a version with semi-open front wheels, I just don't know at this stage the impact it will have downstream of the car. Covering the suspension isn't that hard, I found a nice way to do it, but there are others. Either way, it is F1 style-covered, or LMP style with a convex bulb to go over the suspension. Don't know which one is more efficient tho.

[CAEdevice]

I still think that you can go with something like the latest group C cars (Jag' XJR14) to balance the diffuser, isn't it?

I am also covering wheels at the moment, but I will also have a version with semi-open front wheels, I just don't know at this stage the impact it will have downstream of the car. Covering the suspension isn't that hard, I found a nice way to do it, but there are others. Either way, it is F1 style-covered, or LMP style with a convex bulb to go over the suspension. Don't know which one is more efficient tho.

My design has not started yet (I'm waiting for the calendar and the next rulebook release), I was just curious about the total DF that we could expect. So I modified the 2014 car... and the result was that Cl.A/Cd.A ratio will probably grow from about 1.5/2.5 to 3.0 (wing car would have a Cl.A/Cd.A ratio around 4.5/5.0).

[variante]

My first try is going to be an LMP look alike.
Last year i found drag to be my bottle-neck...even with the last iteration of my car, with ridiculous downforce, i'm not sure i would have won because of its general efficiency. That's why i'm designing a car that gets most downforce from ground effect, and is otherwise designed to reduce drag. I'm also taking (a lot of) care of internal aerodynamics, but i'm not sure it's the right way to go.

I think the car is going to look realistic, with many, many possible interesting solutions and variants to adopt.

Waiting for the definitive regulations!!
BTW i'm still skeptical about those articles forcing people to design LMP looks alike. Instead of them, i would rather suggest some side impact templates in order to guarantee realism.

[MadMatt]

I still think that you can go with something like the latest group C cars (Jag' XJR14) to balance the diffuser, isn't it?

I am also covering wheels at the moment, but I will also have a version with semi-open front wheels, I just don't know at this stage the impact it will have downstream of the car. Covering the suspension isn't that hard, I found a nice way to do it, but there are others. Either way, it is F1 style-covered, or LMP style with a convex bulb to go over the suspension. Don't know which one is more efficient tho.

My design has not started yet (I'm waiting for the calendar and the next rulebook release), I was just curious about the total DF that we could expect. So I modified the 2014 car... and the result was that Cl.A/Cd.A ratio will probably grow from about 1.5/2.5 to 3.0 (wing car would have a Cl.A/Cd.A ratio around 4.5/5.0).

Yes I think getting a L/D ratio of 3 is achievable with these cars at the beginning, and I wouldn't be surprised to see L/D ratios over 4 and maybe even close to 5 by the end of the challenge, but let's see! Also waiting for the rulebook release and how the cars are going to be tested

EDIT: Everybody would have figured that at some point, but just for info, the front wheel diameter is 650mm, and rear 675mm.

[CAEdevice]

Hi, is there any news? What are the plans for 2015? I am a bit worried about the presence (except staff) of only three competitors here on the forum

[RicME85]

Why? Its a bit early for most to be posting.
I have been reading.
Im not going to do anything until the final rules are published.

[CAEdevice]

Why? Its a bit early for most to be posting.
I have been reading.
Im not going to do anything until the final rules are published.

The same for me, I haven't started to design anything.
Anyway, since the rules are not completely defined, I think that the opinion of everyone is important.

I'm happy to hear from you

[cdsavage]

As we're getting close to the end of the year, we will aim to finalise the rulebook soon, hopefully by Christmas. This will give you at least a couple of months to work on your first entries. Calendar and information on CFD testing will follow early next year.

Pre-registration is open here:
http://www.khamsinvirtualracecarchallen ... lenge-2015

You can now contact me at chris at khamsinvirtualracecarchallenge dotcom (or through PMs). As we get closer to the start of the season, I'll strongly encourage everyone to submit a copy of their car to me if there are any doubts or concerns about compliance with all of the rules. Similar to previous years, there will be points penalties if the entry submitted for the points-scoring rounds doesn't comply with the rulebook.

Rulebook update:
A new version of the rulebook is available here: http://www.mediafire.com/view/vdmx76qx5 ... rdraft.pdf
The updated guide files will follow a little later. The main rule changes:

K1.2 - Thin parts may now be 10mm thick instead of 20mm, and wording was included governing the leading edge.

K2.6 - Examples have been given for how bodywork may intersect the suspension volumes. The suspension volume parts have been changed slightly in that they now extend outwards all the way to the wheel, but the region inboard of that hasn't been changed.

K3.1 - Front crash structure area requirement is now at a plane 700mm forward of the front wheel centerline. Changed minimum area to 24000mm^2 and added constraint of no less than 100mm wide or high.

K3.3 - Added rule specifying a single curve must be formed when the diffuser surfaces are intersected with a plane normal to the X-axis, with an exception made for exhausts, if these exit inside the diffuser.

K4.2 - All outlet surfaces must be located at least 600mm rearwards of the rearward-most point of any cooling inlet surface.

Added to the list of options for rules on the sidepod area - a rule specifying that the side impact structure parts (supplied) must form part of the car, with some freedom on positioning. I would welcome any feedback on this rule, for the moment this is just an option. Still undecided on which of these rules, if any, we will use.

Also I'd like to hear if there are any rules in there which are particularly confusing or complex, since we would like to make the rulebook a bit easier to understand compared to 2014.

First version of the side impact structures: http://www.mediafire.com/download/sswgw ... s_rev1.skp
These will be included in future releases of the guide files if we go ahead with this idea.

[CAEdevice]

Thanks for the update.

About the bodywork and suspension intersection: the wheel cover that is shown in the rulebook, should be considered as moving toghether with the wheel? If not (as I suppose), should it consider the space necessary to include the wheel vertical translation?

[cdsavage]

Thanks for the update.

About the bodywork and suspension intersection: the wheel cover that is shown in the rulebook, should be considered as moving toghether with the wheel? If not (as I suppose), should it consider the space necessary to include the wheel vertical translation?

You mean the bodywork covering the wheel in the 2nd and 3rd images? Thats just a cross-section of the fender bodywork, there's no provision for bodywork which moves with the wheels.

It's not neccesary to consider wheel movement. The gap between the boundary of the bodywork volume and the wheel itself would allow for a bit of travel, but in the interest of realism we could increase this gap.

[CAEdevice]

ok, thanks for your answer.
Alternatively a moving volume of the wheel could be included, as already done with the suspension.

What about the simulation environment? In my opinion it should be possible to replicate it for all the partecipants.

[cdsavage]

What about the simulation environment? In my opinion it should be possible to replicate it for all the partecipants.

There will likely be a CFD framework of some sort provided, but we haven't decided on the details. Expect more on this early next year.

[CAEdevice]

Thanks. I think that CFD environment data are fundamental, last year I dedicated to much time before the first race to the car development and few time to the "virtual" wind tunnel, so I had non expected result for two or three races...

[MadMatt]

Would it be possible to have a STEP format of the crash structure? Or some format that can be opened by Catia?

[RicME85]

DWG? http://www.filedropper.com/sideimpactstructuresrev1