[MVRC] Mantium 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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LVDH
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Joined: 31 Mar 2015, 14:23

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

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Hi guys, I was on the road all day.

The inlet looks pretty horrible. This is probably due to bad cell quality. Please send me your case. Having a look at what happened here will be very valuable.

Regarding the Surface LIC in Paraview, I have not checked the newest version. My experience with Paraview is that you always need multiple versions installed as in every version there are features that stop working (that is why MWFlow currently needs two versions). Maybe this time Surface LIC is affected. But surface LIC depends on a good quality mesh as well. So maybe both of your issues are related.

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

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

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LVDH wrote: The inlet looks pretty horrible. This is probably due to bad cell quality. Please send me your case. Having a look at what happened here will be very valuable.
I am running a simulation with the refinement level improved (7 7) for both engine inlet and outlet: from the numbers it does not change very much about the inlet. Tomorrow I will send you the of case.

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

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

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Is someone else having any result? The first impression ia the is more difficult to obtain the required cooling flow (but I still have problems with the sogn of the integral of v over A: inlet and outlet with the same sign).

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TalnoRacing
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Joined: 22 May 2015, 10:50

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

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I need some help please. What other software should be installed along with OpenFOAM? I am trying to follow the discussion on what else is required, but I am afraid I got lost....

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

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

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If you run OpenFoam on Windows you have to download the installer of OpenFoam 1606+ from the offical website: it includes what you need for the virtualization (Vbox, Docker, ...). There is and installlation guide (PDF) that you can find on the MVRC official website.

In this pages you can find the istructions tu run a simulation: the folder structure and the data you have to submit are written in a readme.txt file that is provided with WFlow (MVRC website), a tool that generates a OpenFoam case folder starting from your geometry.

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LVDH
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Joined: 31 Mar 2015, 14:23

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

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TalnoRacing wrote:I need some help please. What other software should be installed along with OpenFOAM? I am trying to follow the discussion on what else is required, but I am afraid I got lost....
As Matteo said, you only need OF+ for Windows and MantiumWFlow.

Matteo I am looking into the case you sent me a few days ago. I will get back to you later.

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

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

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LVDH wrote:
TalnoRacing wrote:I need some help please. What other software should be installed along with OpenFOAM? I am trying to follow the discussion on what else is required, but I am afraid I got lost....
As Matteo said, you only need OF+ for Windows and MantiumWFlow.

Matteo I am looking into the case you sent me a few days ago. I will get back to you later.
Thank you. Tonight I launched a simulation but it has been stopped after 1250 iterations (power blackout...). Anyway: despite I used a finer mesh over the engine inlet, the pressure itnegral was negative, with about the same numbers of the previous simulation. Are you sure that the bc (-0.15m3/s) is correct?

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LVDH
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Joined: 31 Mar 2015, 14:23

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

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You can check yourself if it is correct. In Paraview you should see the air going into that surface.
I am looking at your case. It seems that there are a few cell with a super low pressure on that surface. They then affect the total value. This is probably due to bad cell quality.
Give me some time, I will figure out what is happening.

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

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

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Ok, thank you. There no hurry about that, I am quite sure the the design is correct.

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LVDH
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Joined: 31 Mar 2015, 14:23

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

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CAEdevice wrote:Ok, thank you. There no hurry about that, I am quite sure the the design is correct.
Well at least somebody is.
Once more you have not read what we supply you with.
Have a good look at the rules, if you would have followed what is outlined on the lower part of page seven, you would have less problems.
Your engine inlet face and the vehicle body are exactly on top of each other. Because of that after the meshing process you have a checker board of engine inlet patches and body patches. Now the mass flow has to go through some very narrow gaps and you get crazy pressure values.

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

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

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LVDH wrote:
CAEdevice wrote:Ok, thank you. There no hurry about that, I am quite sure the the design is correct.
Your engine inlet face and the vehicle body are exactly on top of each other
Do you mean that they overlap?

Which is the minimum allowable distance? What about the exhausts?

When I said my design is ok, I was referring to the design, not to the CAD format for OF.

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LVDH
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Joined: 31 Mar 2015, 14:23

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

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Your engine_intake surface is exactly on top of a surface in the intake scope of the part called body. If you have two surfaces exactly on top of each other OF does not know on which surface to snap to. So you could pull the surface on body back some 20-50mm or pull the engine_intake a bit forward. After doing that you will get better results. Also the added refinement will not be necessary.

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TalnoRacing
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Joined: 22 May 2015, 10:50

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

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LVDH wrote:
TalnoRacing wrote:I need some help please. What other software should be installed along with OpenFOAM? I am trying to follow the discussion on what else is required, but I am afraid I got lost....
As Matteo said, you only need OF+ for Windows and MantiumWFlow.
Thank you for the help.

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

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

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Ok, after modifying the position of the "engine intake" surface (50mm forward the inlet surface of the car-body) the issue with the airscope has been solved.

I am curious about the results you are receving about the cooling flow. I have about 1m3/s (2m3/s considering the whole car). It is not enough for the rulebook and I am having difficulties to improve it.

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

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

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Hi everybody, what a silence when there is only a week before the first race.

I am struggling with cooling issues, CoP and lower downforce then expected, but I have good news for LDVH: the simulation runs without issues. I only have some minor problems: tomorrow I will send you the case folder and the logs in order to discuss (here) some small things.