[KVRC] Khamsin Virtual Racecar Challenge 2016

Post here information about your own engineering projects, including but not limited to building your own car or designing a virtual car through CAD.
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CAEdevice
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Joined: 09 Jan 2014, 15:33
Location: Erba, Italy

Re: Khamsin Virtual Racecar Challenge 2016

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A curiosity: how much time (on average) is required for each car preprocessing? How much for legality check / rendering / CFD preparation?

Generally speaking: I am convinced that sketchup gives some advantages in the short period (it is easier to learn), but the use of a real cad (producing not faceted geometry) would be better in the long term for both partecipants and organizers (FreeCAD, for those who like parametric modeling, or Blender, for those who prefer direct modeling, for example, are free and open source).

To prepare and repair the geometry for CFD starting from a STEP would be easier, I think, for Chris (and the stl would more uniform if generated by a professional CAD, by the organization).
Last edited by CAEdevice on 27 Mar 2016, 18:48, edited 1 time in total.

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RicME85
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Re: Khamsin Virtual Racecar Challenge 2016

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Don't see the need for Chris to produce the renders. Should be the competitor that does them. Takes 30mins to do it in Kerkythea with a Sketchup model (setting the colours then the actual rendering process).

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CAEdevice
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Re: Khamsin Virtual Racecar Challenge 2016

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RicME85 wrote:Don't see the need for Chris to produce the renders. Should be the competitor that does them. Takes 30mins to do it in Kerkythea with a Sketchup model (setting the colours then the actual rendering process).
I think that the possibility to see the geometry of other cars is fondamental for the challenge, but I agree that it is an heavy duty for Chris. To include a couple of views of the car into the submission (even a good screencapture from sketchup) should be mandatory.

About the cfd images I have many doubts and I would prefer to limit them, but I am only an (happy) partecipant so I would accept what the organizers decide.

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RicME85
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Re: Khamsin Virtual Racecar Challenge 2016

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I agree Matteo, that's why I said the competitor does them.
I might make a tutorial for doing a Sketchup to Kerkythea rendering if it will mean more people do renders thus lightening the load on Chris.

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CAEdevice
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Joined: 09 Jan 2014, 15:33
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Re: Khamsin Virtual Racecar Challenge 2016

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I have just received the results: I am very happy not with the numbers themselves, but for the consistency with the local solver, that was a issue last year.

Thank you Julien!

The only minor issue is that the scale range of the pictures is too wide, and everything is blue :)

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machin
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Re: Khamsin Virtual Racecar Challenge 2016

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What is the file type in the GZ archive? It doesn't seem to have an extension.... I thought it would be a *.foam file but paraview throws up an error about "no time steps" when I try to open it.....
COMPETITION CAR ENGINEERING -Home of VIRTUAL STOPWATCH

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RicME85
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Re: Khamsin Virtual Racecar Challenge 2016

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Inside the .GZ is a .TAR that you have to extract, that then gives that folder analysis, in there will be the STL files and a folder called oneClickCFD_analysis, in that folder is oneClickCFD_analysis which is a HTML file that has the report and a file called analysis which is your FOAM file for use in Paraview

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machin
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Re: Khamsin Virtual Racecar Challenge 2016

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RicME85 wrote:Inside the .GZ is a .TAR that you have to extract, that then gives that folder analysis, in there will be the STL files and a folder called oneClickCFD_analysis, in that folder is oneClickCFD_analysis which is a HTML file that has the report and a file called analysis which is your FOAM file for use in Paraview
Perfect, thanks!
COMPETITION CAR ENGINEERING -Home of VIRTUAL STOPWATCH

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Alonso Fan
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Joined: 06 Apr 2013, 18:21

Re: Khamsin Virtual Racecar Challenge 2016

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i'm a bit curious as to the difference between the real wec cars and the kvrc template, some of the real cars seem to have a lower rear wing

example
Image

autosport

How come the rear wing template in the template is so high? or is it just a guide and we can make it lower too?

thanks
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CAEdevice
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Joined: 09 Jan 2014, 15:33
Location: Erba, Italy

Re: Khamsin Virtual Racecar Challenge 2016

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Alonso Fan wrote:i'm a bit curious as to the difference between the real wec cars and the kvrc template, some of the real cars seem to have a lower rear wing

example
http://images.autosport.com/editorial/1395917671.jpg

autosport

How come the rear wing template in the template is so high? or is it just a guide and we can make it lower too?

thanks
I tested a lower rear wing: it gives less df but it helps efficiency. Maybe it could be considered for the last two races
Last edited by CAEdevice on 28 Mar 2016, 13:53, edited 1 time in total.

cdsavage
cdsavage
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Joined: 25 Apr 2010, 13:28

Re: Khamsin Virtual Racecar Challenge 2016

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The rectangle guide is just there to show how large the Y-Z section of the wing may be. The wing profiles can be placed anywhere inside the rear wing volume.

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Alonso Fan
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Re: Khamsin Virtual Racecar Challenge 2016

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cdsavage wrote:The rectangle guide is just there to show how large the Y-Z section of the wing may be. The wing profiles can be placed anywhere inside the rear wing volume.
Right, thanks, just what I was looking for
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Alonso Fan
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Re: Khamsin Virtual Racecar Challenge 2016

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CAEdevice wrote:
Alonso Fan wrote:i'm a bit curious as to the difference between the real wec cars and the kvrc template, some of the real cars seem to have a lower rear wing

example
http://images.autosport.com/editorial/1395917671.jpg

autosport

How come the rear wing template in the template is so high? or is it just a guide and we can make it lower too?

thanks
I tested a lower rear wing: it gives less df but it helps efficiency. Maybe it could be considered for the last two races

That's interesting. Thanks
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etsmc
etsmc
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Re: Khamsin Virtual Racecar Challenge 2016

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well got my results and I must have sent the wrong file in for the wing-front as it was missing the front wing and only included the front diffuser but happy none the less with the results as I have still been unable to complete a local run of OCCFD.

The analysis was undertaken for the full car.

The drag and downforce performance predicted by the simulation are:
Total drag: 1761.38 N
Front wing(s) drag: 287.19 N
Rear wing(s) drag: 287.16 N
Drag coefficient - Cd: 0.84
Drag area - Cd.A: 1.47 m2
Total Downforce: -3999.75 N
Front wing(s) downforce: -1884.53 N
Rear wing(s) downforce: -1846.47 N
Downforce coefficient - Cl: -1.91
Downforce area - Cl.A: -3.34 m2

CoP of downforce: 1.532 m along streamwise (Y) direction from Y = 0.00 m.
KVRC Only: Corrected CoP of downforce: 1.591 m along streamwise (Y) direction from Y = 0.00 m.

The pressure at intake and exhaust are:
Engine intake, Area: 0.018m2 - Compliant
Surface integral of pressure: 4.35 Pa.m2
Engine exhaust, Area: 0.011m2 - Compliant
Surface integral of pressure: -4.59 Pa.m2
Cooling intake, Area: 0.401m2 - Compliant
Cooling exhaust, Area: 0.402m2 - Compliant
Differential of surface integral of pressure: -269.23 Pa.m2


A good start to the year now to get some more downforce.

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SR71
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Joined: 27 Jan 2016, 21:23

Re: Khamsin Virtual Racecar Challenge 2016

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Hey Guys,

I'm running 1.1-000 one-click on windows 10. I'm able to run basic simulations on my car, did I read a while back that upgrading to the latest one click is breaking the software?

If I upgrade should I expect problems?

Also, when is the next race :-) ?

Thanks,
SR71