Khamsin Virtual Racecar Challenge 2015

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

Re: Khamsin Virtual Racecar Challenge 2015

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Rulebook release candidate 2 posted on the KVRC site - http://www.khamsinvirtualracecarchallen ... lenge-2015. No real rule changes, but extra wording was added to the K1.* rules concerning units, and how parts should be split and named before submitting. The option for submitting one half of the car has been removed since OCCFD now performs a simulation on the full car.

I don't anticipate any more rule changes, other than if changes are necessary to the submission process, etc.

One thing which may still need to change is the units of the supplied files. To make sure that any exported STL files are in the correct scale, you can open the STL in paraview and click 'apply' to display it. Then in the information panel, there is a section showing the bounds in the axes. If this shows something like -1 to +4 in Y, then the units are correct. If it shows something like -1e3 to +4e3 then the file has been exported with 1 unit = 1mm, and it needs to be 1 unit = 1m.

To export STL files from sketchup, I've been using an older version of the sketchup-stl plugin which doesn't provide an option for which units to use on export. When I export, it appears to use 1 unit = 1mm and so I need to scale the model down by a factor of 1000 before exporting.

Let me know if any STL files you are producing can easily be exported in the correct units, or whether you are needing to manually scale the model down by 1000 before exporting. If so, I'll scale down the guide files so that no extra re-scaling is necessary.

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

Re: Khamsin Virtual Racecar Challenge 2015

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Thanks Chris.

@Julien: I'm out of office so I can't test the complete car. With the.new release of OCCFD most of the issues seem to be.solved. I still receive a geometry error (something like "can't compute area...") but the simulations seems to be completed without any divergence error. I hope to give you more details when I'm back on friday.

EDIT: here is the last error message, I confirm that the simulation has been completed

"One-click CFD Calculator for Vehicle
Version 0.0 (rc3)
Copyright (C) 2014 Julien de Charentenay, PhD
Distributed by Khamsin Virtual Racecar Challenge (aka KVRC) - http://www.khamsin
virtualracecarchallenge.com
Simulation starting time 2015-02-03 10:55:27 +0100
================================================================================
===========
Starting simulation for file:
C:/Users/Matteo/Desktop/test/test.stl
Velocity: 44.7
Ground level: -0.0445
Simulating full car
Check file and solid names for unacceptable characters.
Supported characters are letters, numbers, "-", "_".
Unsupported characters have been identified. The geometry names will be sanitize
d.
Assessing physical bounds of the geometry
Physical bounds: [-1.0000170469284058,-1.024999976158142,0.03999999910593033] to
[1.0000170469284058,4.0,1.0049999952316284]
==================== Running simulation 0 ================================
Generate background mesh using blockMesh...
Extract geometry features using surfaceFeatureExtract...
Generate computational mesh using snappyHexMesh...
Running analysis using simpleFoam...
==================== Running simulation 1 ================================
Generate background mesh using blockMesh...
Extract geometry features using surfaceFeatureExtract...
--------------------------------------------------------------------------
WARNING: An invalid value was given for btl_tcp_if_exclude. This
value will be ignored.

Local host: Galois
Value: 127.0.0.1/8
Message: Did not find interface matching this subnet
--------------------------------------------------------------------------
--------------------------------------------------------------------------
WARNING: An invalid value was given for btl_tcp_if_exclude. This
value will be ignored.

Local host: Galois
Value: 127.0.0.1/8
Message: Did not find interface matching this subnet
--------------------------------------------------------------------------
--------------------------------------------------------------------------
WARNING: An invalid value was given for btl_tcp_if_exclude. This
value will be ignored.

Local host: Galois
Value: 127.0.0.1/8
Message: Did not find interface matching this subnet
--------------------------------------------------------------------------
--------------------------------------------------------------------------
WARNING: An invalid value was given for btl_tcp_if_exclude. This
value will be ignored.

Local host: Galois
Value: 127.0.0.1/8
Message: Did not find interface matching this subnet
--------------------------------------------------------------------------
Generate computational mesh using snappyHexMesh...
Map previous solution onto the new mesh...
Running analysis using simpleFoam...
Simulation completion time 2015-02-03 13:21:12 +0100
Post-processing analysis for geometry test
--------------------------------------------------------------------------
WARNING: An invalid value was given for btl_tcp_if_exclude. This
value will be ignored.

Local host: Galois
Value: 127.0.0.1/8
Message: Did not find interface matching this subnet
--------------------------------------------------------------------------
--------------------------------------------------------------------------
WARNING: An invalid value was given for btl_tcp_if_exclude. This
value will be ignored.

Local host: Galois
Value: 127.0.0.1/8
Message: Did not find interface matching this subnet
--------------------------------------------------------------------------
Error occured with message:
Error when assessing frontal area. It looks like the geometry was not properly
modelled.

Backtrace: C:/Users/Matteo/AppData/Local/Temp/ocrF7A4.tmp/src/mainOneClickCFDVeh
icle.rb:871:in `getFrontalArea'
C:/Users/Matteo/AppData/Local/Temp/ocrF7A4.tmp/src/mainOneClickCFDVehicle.rb:101
1:in `block in postProcess'
C:/Users/Matteo/AppData/Local/Temp/ocrF7A4.tmp/src/mainOneClickCFDVehicle.rb:943
:in `open'
C:/Users/Matteo/AppData/Local/Temp/ocrF7A4.tmp/src/mainOneClickCFDVehicle.rb:943
:in `postProcess'
C:/Users/Matteo/AppData/Local/Temp/ocrF7A4.tmp/src/mainOneClickCFDVehicle.rb:184
:in `start'
C:/Users/Matteo/AppData/Local/Temp/ocrF7A4.tmp/src/mainOneClickCFDVehicle.rb:141
2:in `<main>'
Press enter to close the window
Last edited by CAEdevice on 03 Feb 2015, 14:27, edited 2 times in total.

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andylaurence
123
Joined: 19 Jul 2011, 15:35

Re: Khamsin Virtual Racecar Challenge 2015

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How does OCCFD determine the OpenFOAM version? I'm getting an error:

Error occured with message:
Unable to identify openFOAM version. Stop simulation.

I've got OpenFOAM in C:\Program Files (x86)\OpenFOAM\ and have tried it with DOS_Mode.bat at C:\Program Files (x86)\OpenFOAM\OpenFOAM\DOS_Mode.bat, and C:\Program Files (x86)\OpenFOAM\DOS_Mode.bat as well as copying the contents of OpenFoam-2.1.x to C:\Program Files (x86)\OpenFOAM\

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

Re: Khamsin Virtual Racecar Challenge 2015

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andylaurence wrote:How does OCCFD determine the OpenFOAM version? I'm getting an error:

Error occured with message:
Unable to identify openFOAM version. Stop simulation.

I've got OpenFOAM in C:\Program Files (x86)\OpenFOAM\ and have tried it with DOS_Mode.bat at C:\Program Files (x86)\OpenFOAM\OpenFOAM\DOS_Mode.bat, and C:\Program Files (x86)\OpenFOAM\DOS_Mode.bat as well as copying the contents of OpenFoam-2.1.x to C:\Program Files (x86)\OpenFOAM\
Have you "ticked ADD to path" while installing open-MPI?

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andylaurence
123
Joined: 19 Jul 2011, 15:35

Re: Khamsin Virtual Racecar Challenge 2015

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Yep. Added to path for all users, although typing path at the command line doesn't show it. Can you show me the results of your Path and the full path to DOS_Mode.bat, please? All I can see in the environment variables is:

OPENFOAM=C:\Program Files (x86)\OpenFOAM\OpenFOAM

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

Re: Khamsin Virtual Racecar Challenge 2015

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andylaurence wrote:Yep. Added to path for all users, although typing path at the command line doesn't show it. Can you show me the results of your Path and the full path to DOS_Mode.bat, please? All I can see in the environment variables is:

OPENFOAM=C:\Program Files (x86)\OpenFOAM\OpenFOAM
Open Foam "bin" directory is in: C:\Program Files\OpenFOAM\OpenFOAM-2.1.x
DOS_mode is in: C:\Program Files\OpenFOAM

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andylaurence
123
Joined: 19 Jul 2011, 15:35

Re: Khamsin Virtual Racecar Challenge 2015

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Thanks. I've replicated that, but same problem. What does the result of "path" look like on your system?

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

Re: Khamsin Virtual Racecar Challenge 2015

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andylaurence wrote:Thanks. I've replicated that, but same problem. What does the result of "path" look like on your system?
I looked between the system variables but I could not find it... where do I have to search?

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andylaurence
123
Joined: 19 Jul 2011, 15:35

Re: Khamsin Virtual Racecar Challenge 2015

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I can't see anything on the path either. When I type "path" at the command line, all I get back are system folders and other apps I've installed.

MadMatt
MadMatt
125
Joined: 08 Jan 2011, 16:04

Re: Khamsin Virtual Racecar Challenge 2015

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Andy I have the same error message as well, but the simulation runs fine :)

Xwang
Xwang
29
Joined: 02 Dec 2012, 11:12

Re: Khamsin Virtual Racecar Challenge 2015

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Is it possible to run OCCFD on linux?

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

Re: Khamsin Virtual Racecar Challenge 2015

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Thought I would take a look at OCCFD to see how is it was out of curiosity as I had no issues running Khamsin in previous years and somehow got the pvbatch error even with the latest version.

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

Re: Khamsin Virtual Racecar Challenge 2015

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Xwang wrote:Is it possible to run OCCFD on linux?
I don't think so, but you can run OpenFoam + Helyx OS trying to use the same boundary contions.

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

Re: Khamsin Virtual Racecar Challenge 2015

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I have three more questions about the rules:

1) how much space should be placed between the tire and the bodywork? I'm using a minimum distance of 10mm
2) In the vertical direction the movement of the wheels should be taken into account? Wich stroke value we should use? I guess about 40 or 50mm
3) Is there an extimation of the COP?

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

Re: Khamsin Virtual Racecar Challenge 2015

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CAEdevice wrote:1) how much space should be placed between the tire and the bodywork? I'm using a minimum distance of 10mm
There shouldn't be a need to worry about the spacing between the wheels and bodywork. The cut-outs in the bodywork volume in the wheel areas already provide for this. If it turns out that we got this wrong and there are meshing issues with this gap, we will reduce the size of the wheels on our end.
CAEdevice wrote:2) In the vertical direction the movement of the wheels should be taken into account? Wich stroke value we should use? I guess about 40 or 50mm
Vertical movement of the wheels is not being considered.
CAEdevice wrote:3) Is there an extimation of the COP?
COP should be around 45% front. We haven't officially committed to this value yet, but I'd be surprised if it ends up being too far from this.