Khamsin Virtual Racecar challenge 2013 (CFD model racing)

[astracrazy]

I have saw all previous project and sincerely i'm pretty sure almost of them didnt really respect 2013 regulation. I dont know if your software to manage how aerodynamism work, but need to put more checking rules like if the car pass the crash test etc.

I have didnt read all the rules, but internal part...

Yes, regarding the rules we tend to agree which is why we are working on our own rule book which will be easier to govern. This year there were a few KVRC pacific rules and the rest was open on the f1 rules - hard to govern. No unfortunately our program won't cover things like crash test, just purely wind tunnel simulation. I think people can be sensible on what possibly would and what would not pass.

We supply the suspension/wheel/brake assembly, engine, gearbox, helmet and cockpit template. To govern the sidepod size to prevent unrealistic size sidepods, they must meet the area requirements in two cross sections.

i read it briefly and i think there's a 0 in excess in K8.3b (50000mm2 instead of 5000mm2). And yes, those measures look realistic.

I'll upload tank/engine/gearbox/crash structure complex as soon as possible... i just hoped for some more official images for greater accuracy...

No it should be 50000mm2, 5000 would be too small. For example, my 2013 model = just over 59000mm2 at this cross section. Try it on your model from this year and let me know what result you get, bare in mind the sidepods are meant to be slightly bigger for 2014

Please send me your engine and gearbox for review, excluding tank and crash structure (not a spec part this year).

[variante]

ah, damn it, you're right...my eyes betrayed me...

I'll send you the powertrain tomorrow (the tank is just ment to facilitate engine positioning, but can be easily deleted)

[Schifty]

When the basic file will be available for 2014 regulation?

[astracrazy]

This is the last draft of the rules so id expect this time next week. It will be a draft version to check everything is correct. Obviously you can use it. A welcome pack with all final files will be released in i would say 2 weeks

[cdsavage]

After much nitpicking I am mostly happy with the rulebook Some comments on draft 3:

-Sidepod cross section areas - After drawing these out I think the rearward one isnt necessary at all. I think it overly penalizes certain sidepod designs which arent any smaller when looking at internal volume. I think you could also drop the first area down to about 100000 but that is just personal preference.

-Center of area for the nose (5.1) at 185mm - should probably be marked as an approximate measure, I dont know if sketchup will give you center of area. K5.4A should probably also be approximate.

-Missing dimension for K5.6B, which you have noted - Part B is probably not neccesary, if you just specify somewhere that all the bodywork has to form one contiguous volume (IE the front wing and any other parts have to be connected to the tub). You already have a minimum width for the pylons so there isnt a big advantage in having a small side area.

-K6.2 - the min width probably only needs to apply to the part of the endplate supporting the wing, IE forward of a point 350mm rearward of the RWCL

-K7.8B "which must be constant curvature" can probably be removed to make judging easier, it wont have a big impact anyway

-K4.3 - This should probably make clear which "top face of the entry template" it refers to (the upper of the two top surfaces). Maybe include an annotation in the guide file if possible, otherwise include the image that I had in my first draft?

Some things I am OK with keeping, but they may need to be looked at:
-sidepod inlet no less than 450mm forward of CC (also the forward sidepod X section area is 300mm forward of CC)
-cooling outlet area of 20000 - it was 26000 last year
-K4.5 - enclosed area for the roll structure - is everybody OK with being able to measure this on their cars?
-Same thing for K5.4 A and B - is everybody comfortable with being able to comply with these?

Just a clarity thing, not all of the guide boxes that I provided are referenced in draft 3 yet but you are probably working on that anyway. Currently I have guides for:
-Overall allowed volume
-R75 volume (K8.2)
-Min width of tub
-K4.2
-K5.5
-FW and RW pillars
-Rear wing
-Exhaust outlet
-Diffuser height
-K8.1
-K8.2
-Mirrors
Are there any others needed?

Is everybody clear what is meant by "a longitudinal vertical plane", "vertical section" etc?

[astracrazy]

-Sidepod cross section areas - After drawing these out I think the rearward one isnt necessary at all. I think it overly penalizes certain sidepod designs which arent any smaller when looking at internal volume. I think you could also drop the first area down to about 100000 but that is just personal preference.

I think the rear one is, otherwise your going to get unrealistic size sidepods for what is expected for 2014. Although i'm free to look at the size.

-Center of area for the nose (5.1) at 185mm - should probably be marked as an approximate measure, I dont know if sketchup will give you center of area. K5.4A should probably also be approximate.

Yes, (***) added for both

-Missing dimension for K5.6B, which you have noted - Part B is probably not neccesary, if you just specify somewhere that all the bodywork has to form one contiguous volume (IE the front wing and any other parts have to be connected to the tub). You already have a minimum width for the pylons so there isnt a big advantage in having a small side area.

I think there needs to be a minimum area specified otherwise the pillion could be unrealistically small?

-K6.2 - the min width probably only needs to apply to the part of the endplate supporting the wing, IE forward of a point 350mm rearward of the RWCL

true actually, we have seen some endplate designs which would not be possible with the rule as it is.
"Furthermore when viewed from above, forward of a point 350mm behind the rear wheel center line, have a width no less than 10mm."

-K7.8B "which must be constant curvature" can probably be removed to make judging easier, it wont have a big impact anyway

I agree

-K4.3 - This should probably make clear which "top face of the entry template" it refers to (the upper of the two top surfaces).

"This section must lie entirely above the upper top face* of the cockpit entry template with the bottom edge of the section lying on the upper top face* of the cockpit entry template.
* located between section CC and 250mm forward of section CC" ?

a) sidepod inlet no less than 450mm forward of CC (also the forward sidepod X section area is 300mm forward of CC)
b) cooling outlet area of 20000 - it was 26000 last year
c) K4.5 - enclosed area for the roll structure - is everybody OK with being able to measure this on their cars?
d) Same thing for K5.4 A and B - is everybody comfortable with being able to comply with these?

a) I done this to allow for a smooth transition. The sidepod inlet is required to only be 45000mm2 where the cross section required is 120000mm2
b) As more cooling is required for 2014, i will increase this to 30000mm2

Ye i'm working on the rule boxes. Everything is covered i think. Once this is finalised i'll upload a draft of the rule box with the spec parts.

Thanks for your help. Again, this is the last draft so if you have suggested changes please do so - your only helping. I'm going to set the cut off date as 9th December. Then hopefully by 11th have the rule box with spec parts uploaded and have one draft run with that which will last 1 week

I want to try and get the rules and rule box (basic file) finalised and a welcome pack set up before x-mas so everyone will have around 3 months to build there cars with everything in place.

Luke

[variante]

-Sidepod cross section areas - After drawing these out I think the rearward one isnt necessary at all. I think it overly penalizes certain sidepod designs which arent any smaller when looking at internal volume. I think you could also drop the first area down to about 100000 but that is just personal preference.

rear section should help keeping space for exhaust tubes, and if well wrote down that rule will reach that targer, but i recognize it's an hard task...so i stay neutral.
About 100000mm2 rule: i was already surprised by how small a 120000mm2 section is, so...
However, it might help not defining the "300mm forward of section CC" part, replacing it with "at its maximum width, sidepod's section...": it gives more freedom. But, again, i don't care as long as we keep the minimum of 120000mm2.

As a side note, i suggest to further simplify the rules in order not to intimidate potential challengers. For example we could replace some complex rule (such as the 75mm radius rule) and just use the "rules visualizer".

[cdsavage]

I think there needs to be a minimum area specified otherwise the pillion could be unrealistically small?

Its not a big issue, I suggested removing it mainly to ease the workload in judging - there will be quite a lot to assess for each car

I've PMed you about the sidepod areas. My main issue is that it will make certain designs impossible which should otherwise not be illegal, and I dont think removing that rule will allow too many unrealistic designs, at least none that will give an advantage.

About 100000mm2 rule: i was already surprised by how small a 120000mm2 section is, so...
However, it might help not defining the "300mm forward of section CC" part, replacing it with "at its maximum width, sidepod's section...": it gives more freedom. But, again, i don't care as long as we keep the minimum of 120000mm2.

If I think its too large and you think its too small, lets keep it at 120

As a side note, i suggest to further simplify the rules in order not to intimidate potential challengers. For example we could replace some complex rule (such as the 75mm radius rule) and just use the "rules visualizer".

For that particular rule, and a number of others, there will be a guide included to show the exact volume where the rule applies. I have talked to Luke about simplifying that rule and we havent been able to come up with any alternative to just saying that the radius will be judged very loosely.

I agree that there is more that could be done to simplify things, but having the guides should help. If there are any other rules that you think need guide boxes then let me know.

[astracrazy]

However, it might help not defining the "300mm forward of section CC" part, replacing it with "at its maximum width

Its not a bad idea.

As a side note, i suggest to further simplify the rules in order not to intimidate potential challengers. For example we could replace some complex rule (such as the 75mm radius rule) and just use the "rules visualizer".

It should be ok, we are all here if anyone has any questions. I have stated at the end of that rule that less than 75mm is permitted as long as the purpose of the rule is respected.

Its difficult to become too simple because then it becomes too open.

Hopefully with the basic file (rule box) I can ease it a little, it will be easy to identify where each rule is located on the car - thats for sure.

[Schifty]

What should be nice to have, is a blue print of the part you will provide to us to be able to start the design ''on paper''

[astracrazy]

You will be able to do that yourself with the rule box file - you can print from sketchup so you will be able to print out the rule boxes in 2d view

[Schifty]

Great thing !

[astracrazy]

just tested it now, if you use fit to page and print quality high def. it comes out really good.

Bare with me until about the 11th and i will release that file with the rule boxes and spec parts

On a side note: We have all the spec parts now

[Schifty]

I have register my team, 2013 side, hope still work has a entry for 2014 one

[astracrazy]

It won't do anything unfortunately. I think Julien should be doing a pre-registration form soon. Then a full registration form closer the time which includes payment. The welcome pack will be open to everybody now as well unlike last year where it was only for people who registered - it should hopefully build a bit more interest.

For 5 races the max price will be $50 so £30. Julien is finalising the cost per race per car atm. Anything left over will be divided between 1st-3rd