Page 75 of 91

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 15 Feb 2017, 20:17
by CAEdevice
LVDH wrote:You are right, the values are carry over from the full version but I will remove unnecessary stuff for the new MVRC edition which I will release soon. If you see anything else which should be kicked out just let me know. Removing stuff is easy.
Hi, I can't check it now, but I remeber that there are some wrong units for the pressure resultants (I used the "d" release).

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 15 Feb 2017, 20:23
by rjsa
Ins't it the HX flow which is single sided and reading Pa*m^2

Thx for looking at the CD and Area stuff.

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 15 Feb 2017, 23:25
by JJR
Hi Matteo this are CdA values for some lmp cars :

Lotus lmp2/2012/CdA 0.90 - avarage mapping
Dome - Pescarolo lmp1/2012/CdA 0.96 - avarage mapping
Pescarolo P03 lmp1(AMR1 based)/2012/ CdA 1,03 - avarage mapping

Lotus used to be fastest lmp2 car on straights.
Pescarolo was open cockpit car and slowes lmp1 car on straights.
Dome was beautiful car :)

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 16 Feb 2017, 00:05
by CAEdevice
Hi JJR, thank you very much for the interesting data. Our cars (the best cars of the last Le Mans race) are significantly less draggy (about 15% less). I use the Done as reference (it is similar our cars).

Which could be the reason? Maybe narrower tyres? Or simplified cooling (no oil nor brake cooling)? Or the porosity of the hx? Just a curiosity.

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 16 Feb 2017, 00:47
by rjsa
Just the clean skin from theoretical cars might count for quite a bit. If we started slicing and dicing panels and adding internal tubing I suppose figures should start changing quite fast.

And like you mention, all the stuff that is simplified or left behind too.

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 16 Feb 2017, 00:54
by rjsa
How big is the COP handicap? 50mm?

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 16 Feb 2017, 01:26
by rjsa
Back on the wishes:

-Can we get more slices? Half the current spacing?
-Is there something like Surface LIC in the plans?

My old iMac's graphics card crashes 3 times out of 5 I try it with paraview...

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 16 Feb 2017, 10:09
by JJR
CAEdevice wrote:Hi JJR, thank you very much for the interesting data. Our cars (the best cars of the last Le Mans race) are significantly less draggy (about 15% less). I use the Done as reference (it is similar our cars).

What could be the reason? Maybe narrower tyres? Or simplified cooling (no oil or brake cooling? Or the porosity of the hx? Just a curiosity.
Our cars are 5000 mm long vs LMP 4650mm (longer car is better ), lmp cars have mandatory cutouts on front and rear wheel arches and 15mm mandatory rear wing gurney. Also numbers are for avarage ride hight mapping in rake situation so about 35/55 mm and KVRC car is simulating with 45/45 - no floor rake. And lmp car have also stepped floor.
So I think lmp carhas these disadvantages and yeas we are missing brakes cooling, cockpit ventilation ....

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 16 Feb 2017, 12:09
by CAEdevice
JJR wrote:
CAEdevice wrote:Hi JJR, thank you very much for the interesting data. Our cars (the best cars of the last Le Mans race) are significantly less draggy (about 15% less). I use the Done as reference (it is similar our cars).

What could be the reason? Maybe narrower tyres? Or simplified cooling (no oil or brake cooling? Or the porosity of the hx? Just a curiosity.
Our cars are 5000 mm long vs LMP 4650mm (longer car is better ), lmp cars have mandatory cutouts on front and rear wheel arches and 15mm mandatory rear wing gurney. Also numbers are for avarage ride hight mapping in rake situation so about 35/55 mm and KVRC car is simulating with 45/45 - no floor rake. And lmp car have also stepped floor.
So I think lmp carhas these disadvantages and yeas we are missing brakes cooling, cockpit ventilation ....
Thank you very much! These points are very interesting.

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 17 Feb 2017, 18:03
by rjsa

Code: Select all

Force Coefficients averaged: Cd: 0.733444, Cl: -3.54725, Cl(f): -1.65669, Cl(r): -1.89056
So I'm going to consider my 2016 test mule retired. L/D = 4.830, uncorrected COP 1.60m & HX flow 3.6m^3/s.

Anxiously expecting the new rulebook :wink:

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 17 Feb 2017, 18:40
by CAEdevice
rjsa wrote:

Code: Select all

Force Coefficients averaged: Cd: 0.733444, Cl: -3.54725, Cl(f): -1.65669, Cl(r): -1.89056[m^3/s]
So I'm going to consider my 2016 test mule retired. L/D = 4.830, uncorrected COP 1.60m & HX flow 3.6m^3/s.

Anxiously expecting the new rulebook :wink:
You are on the podium : )

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 19 Feb 2017, 00:25
by Markus
Reading through these last pages has made me interested in the new season. I was just wondering what CAD programs you use since I realize Sketchup really can“t keep up with more professional programs?

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 19 Feb 2017, 10:02
by CAEdevice
Hi Markus, welcome to the MVRC challenge.

I am not a fan of Sketchup, but consider that Variante won a challenge modeling its car with Sketchup.

The best alternative is parametric CAD, if you are a student you could try a student edition (free or around 100$/year) of Solidworks, SolidEdge, Autodesk360, ...

FreeCAD is opensource, not at the same level as commercial tools but quite good in my opinion.

Also take a look at OnShape demos.

Consider that the opensource car that I will realease for MVRC 2017 could be managed and tweaked with SketchUp and even with simpler tools as the 3D builder provided with Win10.

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 19 Feb 2017, 11:53
by rjsa
I use Rhino3D + T-Splines.

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 19 Feb 2017, 17:35
by Markus
CAEdevice wrote:Hi Markus, welcome to the MVRC challenge.

I am not a fan of Sketchup, but consider that Variante won a challenge modeling its car with Sketchup.

The best alternative is parametric CAD, if you are a student you could try a student edition (free or around 100$/year) of Solidworks, SolidEdge, Autodesk360, ...

FreeCAD is opensource, not at the same level as commercial tools but quite good in my opinion.

Also take a look at OnShape demos.

Consider that the opensource car that I will realease for MVRC 2017 could be managed and tweaked with SketchUp and even with simpler tools as the 3D builder provided with Win10.
That open source car sounds interesting, I did take part in KVRC a couple of years ago using sketchup but spent quite a bit of time trying to get the basics working which meant that it wasn't really possible to do any proper development.