[KVRC] Khamsin Virtual Racecar Challenge 2016

[CAEdevice]

Definitively front downforce is the biggest challenge, specially with a "no front wing" configuration. For next round I have been forced to implement a front winged version in order to balance the car and gain some global downforce. Still too far from Variante.

The same I did for the pre season race (and maybe for the first race). Winglets made me gain 100N in the right place (front area).

Regarding the cooling option 2, I understand that we are going to use the porosity method for next round. Is it possible to have the properties of the porous medium? Ideally the porosity and flow vs pressure drop characteristics.

I'm ging to use op1 untill opt2 will be completeley defined.

BTW: Is anyone running OCCFD in parallel mode? I'm still using the single core option.

[cdsavage]

Regarding the cooling option 2, I understand that we are going to use the porosity method for next round. Is it possible to have the properties of the porous medium? Ideally the porosity and flow vs pressure drop characteristics.

For the upcoming round we will continue to use the 'fallback' method. I'm not sure yet if it will be ready for the following round, but it's possible. We'll make sure to give those details when it's finalized.

Whoa thats an ugly change to the intake on the intro car

Hmm, I thought it looked much more tidy than the original version, the inlet on that one was a bit of a crude rush-job. Anyway the reason for the change there was that the old inlet wasn't fully meeting the 2016 wording for the 50mm height/width requirement, due to the acute corners.

[Alonso Fan]

Sorry, just to clarify, in the 'body' .stl file, am I supposed to include the wheels/suspension too?

[cdsavage]

Sorry, just to clarify, in the 'body' .stl file, am I supposed to include the wheels/suspension too?

No, it should only include the bodywork. None of the supplied parts should be submitted.

[RicME85]

Whoa thats an ugly change to the intake on the intro car

Hmm, I thought it looked much more tidy than the original version, the inlet on that one was a bit of a crude rush-job. Anyway the reason for the change there was that the old inlet wasn't fully meeting the 2016 wording for the 50mm height/width requirement, due to the acute corners.

Think it would look neater if the too surface in front of the intake was flattened so those acute corners could be removed and the intake have a straight bottom edge.

[SR71]

Do we still have "single core" support?

I personally think we've ruined a great aero competition in the name of "cooling".

Cooling and thermals are only going to be reduced as we move into higher power electrics in racing. For us to sacrifice multiple core simulation in what is essentially an aero competition is a bit ridiculous.

If we regain multi-core support I'd love to dip my toes back into the competition.

[julien.decharentenay]

Do we still have "single core" support?

If we regain multi-core support I'd love to dip my toes back into the competition.

I have not removed the Single Core option from OCCFD as I did not get full confirmation that people were successfull with the parallel option. But my expectations are that the move from openFoam by cfdsupport to openfoam by blueCAPE will make the parallel mode working. Can anyone confirm?

The inclusion of cooling was participant lead and aims for making the designing aspect more interesting as one has to manage the airflow for cooling/engine.

[julien.decharentenay]

This is copy of what was send via the mailing list:

This is the last weekend prior to the race #1 Nurburgring submission due date. Hopefully the designs are coming along for all. The submission deadline is 28th April. As Chris mentioned, it does help us to have compliant cars on first submission - so if you can make it compliant we will be forever thankful. If there are compliance issues that needs to be addressed - you will be sent an email on Sunday, the resubmission deadline is 3rd May. This resubmission is only for participants that have submitted by the deadline and should only address the non-compliant issues notified.

Richard and I had a meeting with onShape and SimScale yesterday - which was very productive. Richard is involved for two reasons: he is ok to provide his pre season race design as the starting point for the workshop and I am hoping that he will be sharing some of his knowledge at one of the workshop. The onShape/SimScale/KVRC workshop team will be interesting in the variety of skills - and in my opinion a good reflection on what real project life can look like. The hope is for a set of workshop with the first one in May 2016 - not sure how we are going to achieve this deadline, but at least people at onShape and SimScale get work hours to do it.

OCCFD seems to be doing better, with back to the more normal issues with meshing inside the geometry and a potential biais in the calculation of the CoP that MantiumRAY asked me to investigate. I will look at it and advise. The changes will take place after this race - if required.

On the porosity front, the last version has an implementation. The physics on the cooling radiator (and engine parameters) that is implemented is described in https://juliendecharentenay.wordpress.c ... ntilation/

[HP-Racing]

Do we still have "single core" support?

If we regain multi-core support I'd love to dip my toes back into the competition.

I have not removed the Single Core option from OCCFD as I did not get full confirmation that people were successfull with the parallel option. But my expectations are that the move from openFoam by cfdsupport to openfoam by blueCAPE will make the parallel mode working. Can anyone confirm?

The inclusion of cooling was participant lead and aims for making the designing aspect more interesting as one has to manage the airflow for cooling/engine.

Since the change to the blueCAPE distribution and a bit of tinkering with the MSMPI versions we managed to get parallel mode to work.

[Alonso Fan]

That's excellent! What sort of 'tinkering' is needed? Please can you explain for those who haven't managed to get it to work like me

Thanks

[SR71]

Do we still have "single core" support?

If we regain multi-core support I'd love to dip my toes back into the competition.

I have not removed the Single Core option from OCCFD as I did not get full confirmation that people were successfull with the parallel option. But my expectations are that the move from openFoam by cfdsupport to openfoam by blueCAPE will make the parallel mode working. Can anyone confirm?

The inclusion of cooling was participant lead and aims for making the designing aspect more interesting as one has to manage the airflow for cooling/engine.

I understand it was participant lead. However, had participants been asked "you'll lose multi-core support and see your simulations times increase 3-5x" would we have had the same result?


I'm not saying this was intended, of course you're doing your best. I'm just pointing out hindsight and with perspective what's more important.

[HP-Racing]

That's excellent! What sort of 'tinkering' is needed? Please can you explain for those who haven't managed to get it to work like me

Thanks

Uninstall any version of MSMPI you have on your computer and make sure that these files are deleted:

- Mpiexec.exe
- Smpd.exe
- Msmpi.dll

the first 2 are found in the installation directory of MSMPI and the last is in C:/Windows/System32

On my PC the uninstall routine didn't delete Msmpi.dll for some reason...

Then you just need to install this MSMPI into it's standard installation directory:

https://www.microsoft.com/en-us/downloa ... x?id=36045

To check your installation you can look at the file versions of the 3 mentioned files. They should all be 4.0.3906.0


Alex

[LVDH]

Do we still have "single core" support?

I personally think we've ruined a great aero competition in the name of "cooling".

Cooling and thermals are only going to be reduced as we move into higher power electrics in racing. For us to sacrifice multiple core simulation in what is essentially an aero competition is a bit ridiculous.

If we regain multi-core support I'd love to dip my toes back into the competition.

Hi,
I am sometimes in contact with Julien through email and can imagine what issues he is facing. And I am pretty sure that the cooling options are not the reason for OF not working in parallel on Windows. Anyways you can always use cooling option 1 which is the same it was last year. I have done a test today and it seems to be the faster option. I found a mistake in my porosity setting so I am not 100% sure.
I always thought Julien did a great job making his CFD tool available for everyone running on Windows. Windows and OpenFOAM were never really made for each other. And he is not an OpenFOAM support guy.
Most CFD engineers will have gone through longer periods of simulations crashing no matter what they do. As of today it is still part of this job. So if you are in a CFD competition you have to either live with the fact that even today CFD is not bullet proof or you try fixing it yourself. It would be a shame to not see you car on the grid because of software issues as the car and presentation look outstanding.
And there are workarounds. You could install Linux, on a usb stick or a hard disk you currently do not use, you could install it in a virtual machine or use AWS which runs Linux.

[CAEdevice]

Please don't remove the single core option: it is useful to run a simulation while working on the pc

[CAEdevice]

I agree with Mantium, even if I am not a cfd specialist.

OCCFD is a great tool and it is necessary to involve not analysts. On the other side ot would be very useful to have the possibility to generate a case foLder ready to be run on a windows or linux workstation: that is what I have done during pre season, editing the files generated by an old release of OCCFD.

The limit I have is that I am not able to extract the pressure differential and to write it in a log (as it happens with the areo forces). Another issues for a beginner is the manage the double start (preliminary run). What about starting directly from the second stage?