[KVRC] Khamsin Virtual Racecar Challenge 2016

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CAEdevice
49
Joined: 09 Jan 2014, 15:33
Location: Erba, Italy

Re: Khamsin Virtual Racecar Challenge 2016

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Hi Chris, is the Opt2/B (not porous) confirmed?

I have the impression that Opt1 will be a little more convenient if the Opt2/B inlets areas will be constrained. In my opinion (but we could wait after the pre season race results) the Opt2/B inlets/outlets surfaces would be free or with a lower minimum area (40000mm2?), but with the same pressure×area differetial.

cdsavage
cdsavage
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Joined: 25 Apr 2010, 13:28

Re: Khamsin Virtual Racecar Challenge 2016

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Julien can confirm, but I believe that for the first round at least, we will need to use the fallback method for the entries using K4.1 option 2.

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CAEdevice
49
Joined: 09 Jan 2014, 15:33
Location: Erba, Italy

Re: Khamsin Virtual Racecar Challenge 2016

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Hi, could you confirm that, if I run an Opt2/B with OCCFD, naming the heat exchangers surfaces as "cooling_inlet" and"cooling_outlet", I'm simulating the same official bc that will be applied during a race with Opt2/B?

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variante
138
Joined: 09 Apr 2012, 11:36
Location: Monza

Re: Khamsin Virtual Racecar Challenge 2016

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@TalnoRacing
Very nice car.
The nosecone-cockpit area was clearly inspired by Mantium racer. It looks absolutely awful :D , but i guess it's got a drag advantage, as the airflow is more "free to move" around it. Globally a well designed car.

I have to say that i'm using the very same engine intake solution!

@etsmc
A huge improvement over last year's car. As suggested, a different front upper wing might help.

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TalnoRacing
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Joined: 22 May 2015, 10:50

Re: Khamsin Virtual Racecar Challenge 2016

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@variante - thank you for the compliment. I did look at Mantium's car A LOT. And I agree that the nose cone looks awful, but it is efficient for my overall design.

The engine intake solution is elegant: it reduces frontal area compared with a roof mounted snorkel and I found it reduced lift on my car.

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TalnoRacing
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Joined: 22 May 2015, 10:50

Re: Khamsin Virtual Racecar Challenge 2016

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machin wrote:Ok... so another problem for you nice people on the forum to help out with....

I am trying to save my body parts out of Solidworks into STL format... however the origin doesn't stay where it is in the Solidworks model....

I've checked the "Do not translate STL data" box, highlighted below, and you can see the origin in solidworks is in the right place:-

http://i90.photobucket.com/albums/k248/ ... ktbjcq.jpg

The STL export preview still shows the origin in the right place:-

http://i90.photobucket.com/albums/k248/ ... kjl9zf.jpg

...and yet when I open up the STL file the origin shows up in the volumetric centre of the part!

http://i90.photobucket.com/albums/k248/ ... vmsdas.jpg

Any ideas???
Did you manage to resolve this problem? I noticed that your "units" setting in the "options" menu is in "millimeters". You need to change it to "meters". Before starting modelling, make sure that the model units is set in "MKS" - this is found in the bottom right of the model screen. The default Solidworks setting is "MMGS". After opening and before saving the supplied parts, you have to change this unit setting. You can also change this setting after you already saved your model.

If you don't model in "meters" then your STL file will in fact be in "millimeters", so instead of having a Y+ dimension of 1.0m, you will in fact fact have a Y+ of 1.0mm.

Open your model, change the above setting and re-save the model. Then re-save the STL file making the "units" change. Your origin should be in the right place.

Arno

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machin
162
Joined: 25 Nov 2008, 14:45

Re: Khamsin Virtual Racecar Challenge 2016

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TalnoRacing wrote:Open your model, change the above setting and re-save the model. Then re-save the STL file making the "units" change. Your origin should be in the right place.

Arno
Cheers! I'll give it a try tomorrow!
COMPETITION CAR ENGINEERING -Home of VIRTUAL STOPWATCH

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RicME85
52
Joined: 09 Feb 2012, 13:11
Location: Derby

Re: Khamsin Virtual Racecar Challenge 2016

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Has the OCCFD 'test' setting been changed? I ran it in AWS and it was still running over 24hrs later so terminated it. Previously it was over and done with in minutes.
Have just instead gone for the standard option to see how it goes.

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LVDH
46
Joined: 31 Mar 2015, 14:23

Re: Khamsin Virtual Racecar Challenge 2016

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variante wrote: The nosecone-cockpit area was clearly inspired by Mantium racer. It looks absolutely awful :D ,
TalnoRacing wrote:@variante - thank you for the compliment. I did look at Mantium's car A LOT. And I agree that the nose cone looks awful,
I am glad to help. There was no chance of copying style from my car? I know it is not Italian but there must be something.

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TalnoRacing
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Joined: 22 May 2015, 10:50

Re: Khamsin Virtual Racecar Challenge 2016

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Maybe if my modelling skills were better I could make it look more stylish. By the way, this version looks much better than the first iteration....

graham.reeds
graham.reeds
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Joined: 30 Jul 2015, 09:16

Re: Khamsin Virtual Racecar Challenge 2016

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I have the front wheels fender and part of the floor but I got so annoyed with trying to create a front defuser when my PC crashed I shelved it. Need to pick it up again but I am busy this weekend (new job and a 300 mile move).

cdsavage
cdsavage
19
Joined: 25 Apr 2010, 13:28

Re: Khamsin Virtual Racecar Challenge 2016

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CAEdevice wrote:Hi, could you confirm that, if I run an Opt2/B with OCCFD, naming the heat exchangers surfaces as "cooling_inlet" and"cooling_outlet", I'm simulating the same official bc that will be applied during a race with Opt2/B?
This is correct.

The deadline for the first round is about 2 and a half days from now.

A quick reminder: as explained in the post quoted below, we are using the 'fallback' method for K4.1 option 2 in the first round (the 'intended' method will not be used). This means that those using K4.1 option 2 need to submit the front heat exchanger faces as one part, and the rear heat exchanger faces as another part (rather than submitting the "hx-shape" parts). Since everything has been a bit rushed for this first round, don't worry if the naming and format of the parts isn't completely correct, we'll do our best on our end to correct any minor issues.
etsmc wrote:so we are submitting the following if we have modeled the cooling ducts

body
wing-front
wing-rear
cooling-intake
cooling-exhaust
engine-intake
engine-exhaust
hx-front
hx-rear
parts-offset.txt
Last edited by cdsavage on 19 Mar 2016, 13:25, edited 1 time in total.

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machin
162
Joined: 25 Nov 2008, 14:45

Re: Khamsin Virtual Racecar Challenge 2016

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TalnoRacing wrote: ...Your origin should be in the right place.
Unfortunately this appears not to have worked.... I think it must be a glitch with my (very old) version of Solidworks (2003!!!)....

What I don't know is whether the problem occurs during the STL creation, or when I re-import it to have a look at it....

Matteo (CAEDevice) kindly did an export from his version of SW for me, but when I import it to my version of SW the origin is not in the correct place.... The annoying thing is that it exports (and imports) the origin fine until I do the final mirror... I re-made the model without the final mirror (i.e. by mirroring all the sketches themselves during the build process)... but the problem still exists...

Solidworks file:
http://www.competition-car-engineering. ... _R0.SLDPRT

STL export:-
http://www.competition-car-engineering. ... itB_R0.STL

:-S
COMPETITION CAR ENGINEERING -Home of VIRTUAL STOPWATCH

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CAEdevice
49
Joined: 09 Jan 2014, 15:33
Location: Erba, Italy

Re: Khamsin Virtual Racecar Challenge 2016

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Hi Machin, I can help you with other software I use for stl, but I would see your car.

You could also try to import the stl into sketchup and to translate it into the right place.

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machin
162
Joined: 25 Nov 2008, 14:45

Re: Khamsin Virtual Racecar Challenge 2016

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Cool... I'll try Sketchup... Good idea.

(I'm not worried about people seeing my car... Links to the parts are above!)
COMPETITION CAR ENGINEERING -Home of VIRTUAL STOPWATCH