[KVRC] Khamsin Virtual Racecar Challenge 2016

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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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julien.decharentenay wrote:Hi Gents. SimScale is a good platform - has its limitations, which I tested a lot when I applied there (but it did not get anywhere). I am trying to get in touch with the openFoam foundation directly to see if we can link with them.

In the meantime, I released OCCFD version 1.1 at http://www.khamsinvirtualracecarchallen ... edirects=0 which can be used to calculate the mean pressure at the inlet and outlet (sorry CAEdevice, the full modelling of the radiator is not ready yet). I made some progress, but have not implemented it yet.

I will go through the rule book to get it to a final draft version next week. I think I mentioned this earlier we are looking at a first race in April 2016.
Very good news! The OpenFoam foundation would be great to work with, but I think that small commercial companies would have more advantages becoming a sponsor (Engys? SimFlow/RapidCFD? There would be other examples but not OF based).

Thank you very much for releasing OCCFD 1.1. Wich are the differences from 1.0? I would like to test the 2015 old car with it, do you have any reference parameter for inlet/outlet pressure, or pressure per surface?

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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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I'm testing OCCFD 1.1.

My fisrt commnets/questions are:

1) Thank you very much for adding "wings" separate forces measure.
The "other wings" option is very useful, but, how do I activate it? Should I deteach and rename a specifice surface/quilt (i.e. floor, or mirror) and rename it (i.s. wing-floor, wing-mirror)?

2) So many new BC options, thanks!

3) I can't find the "very stable option", so it is almost impossible to run on windows and with openfoam 2.x.x the simulations I completed with OCCFD 1.0. It happens a "divergence error" during the first (single core, preliminary) run.

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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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Ps: the distance from the ground to the floor, is 45mm? Am I wrong or during 2015 it was 40mm?

julien.decharentenay
julien.decharentenay
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Joined: 02 Jun 2012, 12:31

Re: Khamsin Virtual Racecar Challenge 2016

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CAEdevice wrote: 1) Thank you very much for adding "wings" separate forces measure.
The "other wings" option is very useful, but, how do I activate it? Should I deteach and rename a specifice surface/quilt (i.e. floor, or mirror) and rename it (i.s. wing-floor, wing-mirror)?
Happy to help when I can... Sorry but I won't be able to change the axis direction (I am too scared to miss one parameter somewhere if I give the options of choosing the direction - I may have to revert to building a rotation of the STL as a pre-processor in place)...

Front wings are recognised by the tag "f...wing" or "wing-f....", "wing_f..."
Rear wings are recognised by the tag "r....wing" or "wing-r...", "wing_r..."
Other wings would be anything else. "wing-floor" is no good as it would end up as a Front wing. "wing" should be fine"

Note the above are NOT case sensitive...
CAEdevice wrote: 3) I can't find the "very stable option", so it is almost impossible to run on windows and with openfoam 2.x.x the simulations I completed with OCCFD 1.0. It happens a "divergence error" during the first (single core, preliminary) run.
Sorry about this. I uploaded an updated version which has the "very stable option"...

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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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An hypothetic wing including underfloor and diffuser could be named "other_wing", am I right?

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LVDH
46
Joined: 31 Mar 2015, 14:23

Re: Khamsin Virtual Racecar Challenge 2016

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Hi guys,

last Friday Friendship Systems held a lecture at the university of Berlin.
Part of it contained my car which was partially optimized using their software CAESES.
They also encouraged the students to join the competition.
So with some luck we will have a few more entries next season.

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

Re: Khamsin Virtual Racecar Challenge 2016

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Hi everyone,

We are releasing the first draft of the 2016 rulebook. Sorry that it ended up being a bit late. It can be found here:

http://www.khamsinvirtualracecarchallen ... ects=0&d=1

There are 2 major changes for 2016:

1) The addition of a 'subclass' where the bulk of the bodywork is provided, and the entry consists only of the areas around the front wing, rear wing and floor. The rulebook is substantially simpler for these entries - look for the sections highlighted in blue. Anyone choosing to compete in the subclass still earns points towards the main championship, but there is an additional championship for the best-placed entrant in the subclass. Anyone entering the subclass may choose to start modifying the supplied parts at any point during the season, taking themselves out of the running for the subclass championship and competing only for the main championship. The supplied bodywork for the subclass will look something like the images below, with an adjusted "bodywork volume" to match:

Image

Image

2) The geometric requirements for the inlets and outlets have been simplified (the "outer templates" have been removed and the rotation limits are less restrictive), and instead we are specifying some aerodynamic requirements on the inlets and outlets. If the design is found to not meet these requirements when the CFD simulation has been performed, then an engine power penalty is applied in proportion to the under-performance of the cooling system. We are also adding a second option for the cooling inlets and outlets: you may choose to model the entire internal duct running from the inlet to the outlet, with a heat exchanger in the duct. The aerodynamic requirements will apply to the heat exchanger only, the rules on the inlets and outlets are relatively free for this option. We're still including some restrictions on the area of the inlet and outlet faces, since this is new territory and we want to keep this in place in case we've misjudged the numbers.

There have been many other small tweaks to the rulebook. There are a couple of points in particular that we'd like feedback on:
- Should the rules on the visibility of the front suspension templates be relaxed or removed?
- Should the maximum height of the diffuser (320mm in 2015) be lowered?
We're also undecided whether the mandated subclass bodywork should include the bodywork surrounding the front wheels, or if this should be left to the competitor to model themselves.

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

Re: Khamsin Virtual Racecar Challenge 2016

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One of the biggest challenges I found when I tried to model from scratch was that with SketchUp basic you can't do a boolean substraction making wheel arches difficult.

So include the front wheel arches but make them very inefficient.

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

Re: Khamsin Virtual Racecar Challenge 2016

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Really? Anyone using Sketchup needs to sign up to Sketchucation and get their 'store' plugin, from their you can get plugins that make life so easy. Curviloft is fantastic, using that alongside the intersect tool built in did a lot of the work for me.

JJR
JJR
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Joined: 12 Jul 2013, 20:02

Re: Khamsin Virtual Racecar Challenge 2016

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I´m for not to change height of the rear diffuser ( stay as it was in KVRC 2015 competition 320mm).
It gives you more room to experimet. I used for example only 290mm in 2015.

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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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What will the definition of "modifying" be in the context of the subclass? Will it include adding surfaces/features onto the template, or only changes where the template is cut?

I suggest amending the front suspension visibility rule by making the suspension elements thinner, and supplying them in ride height condition only (the current templates are bulky as they represent the maximum travel from ride height).

The bodywork for the subclass should be as per your suggestion. For a newbie and novice there is already enough to learn with regards to the wings, floor and diffuser, and their interactions. If you don't like something and think your own design is more efficient, modify the template and move into the main class.

I agree with JJR on the diffuser.

cdsavage
cdsavage
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Joined: 25 Apr 2010, 13:28

Re: Khamsin Virtual Racecar Challenge 2016

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TalnoRacing wrote:What will the definition of "modifying" be in the context of the subclass? Will it include adding surfaces/features onto the template, or only changes where the template is cut?
The submissions for the subclass won't include the supplied parts - these parts are supplied for reference only (and if you wish to do your own CFD testing). So you only submit the parts you want to add to the standard parts. There is a modified "bodywork volume" for the subclass which matches the supplied bodywork, and this mostly limits these added parts to the regions around the front wing, rear wing and floor.

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machin
162
Joined: 25 Nov 2008, 14:45

Re: Khamsin Virtual Racecar Challenge 2016

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LVDH wrote:Hi guys,

last Friday Friendship Systems held a lecture at the university of Berlin.
Part of it contained my car which was partially optimized using their software CAESES.
They also encouraged the students to join the competition.
So with some luck we will have a few more entries next season.
Good work!
COMPETITION CAR ENGINEERING -Home of VIRTUAL STOPWATCH

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machin
162
Joined: 25 Nov 2008, 14:45

Re: Khamsin Virtual Racecar Challenge 2016

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TalnoRacing wrote: The bodywork for the subclass should be as per your suggestion. For a newbie and novice there is already enough to learn with regards to the wings, floor and diffuser, and their interactions. If you don't like something and think your own design is more efficient, modify the template and move into the main class.
Exactly my thoughts... The subclass should be a beginners class where you don't need to be an expert modeller to achieve a reasonably good result as long as you apply good aerodynamic principles. If you're a good modeller already then I'd say you should be encouraged to join the main class....
COMPETITION CAR ENGINEERING -Home of VIRTUAL STOPWATCH

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machin
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Joined: 25 Nov 2008, 14:45

Re: Khamsin Virtual Racecar Challenge 2016

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cdsavage wrote:The supplied bodywork for the subclass will look something like the images below, with an adjusted "bodywork volume" to match:

http://i.imgur.com/KiwXNI4.jpg

http://i.imgur.com/la98fZt.jpg
.
Looks good to me Chris. =D>
COMPETITION CAR ENGINEERING -Home of VIRTUAL STOPWATCH