Khamsin Virtual Racecar Challenge 2015

[CAEdevice]

It´s completly covered with body and moved 100mm upwards.

A few more images of the top 3:

[...]

http://www.khamsinvirtualracecarchallen ... or_jjr.jpg

I was wondering... where are the front suspensions?

Thanks! The low quality JPG was not clear.

[LVDH]

Is there any chance the KVRC homepage could get updated or we could see the lift and drag values from the last race?
It would be good to have a benchmark.

[machin]

Code: Select all

                      CL.A    CD.A   COP (m)   Time (s)
          Variante    5.39    1.08    1.671     79.361
       Mantium RAY    5.05    1.12    1.694     79.998
        JJR Racing    3.94    0.92    1.704     80.129
         CAEdevice    5.69    1.37    1.619     80.419
          Kineuton    5.52    1.34    1.802     81.137
                TF    5.79    1.39    1.930     81.706
       sjns-Racing    2.40    1.30    1.724     83.574
Mercury Motorsport    3.04    1.25    1.339     83.054 + 0.831p
  Brook Motorsport    1.68    1.29    1.985     84.480

[/size]

[LVDH]

Thanks,

interesting numbers. The low level of downforce on the JJR car is a bit surprising.
Lets hope that CAEdevice can get rid of some drag so we can have our battle to death.

[CAEdevice]

Thanks,

interesting numbers. The low level of downforce on the JJR car is a bit surprising.
Lets hope that CAEdevice can get rid of some drag so we can have our battle to death.

I actually have a serious problem with drag

[LVDH]

Try a lower rear wing and larger end plates.

[CAEdevice]

Try a lower rear wing and larger end plates.

The rear wing height is one of the things I'm going to optimize, but most of the drag is generated by the front wing (the rear wing is needed to balacne the downforce). I would need to dramatically change the design, but I have no time (I'll do for the next season).

[julien.decharentenay]

Just a reminder that the next race is next week - 9 days left before the submission deadline. Good luck to all.

openFoam has released an official windows version of v2.4.0, which can be downloaded at http://www.openfoam.com/products/openfoam-windows.php. It does not work with OCCFD at this stage. It is an interesting development, but also a challenging one as they are using a virtual machine in place of native port. I am not 100% sure how I can integrate it with OCCFD, but I am working on it. If anyone has experience with docker, is it possible to start a VM with specifying a list of commands to run?

[CAEdevice]

I would have a question for Machin (my curiosity). Is the lateral acceleration of the best cars, considering the downforce values, comparable to any real car (C group, ground effect F1, ...)?

[CAEdevice]

Just a reminder that the next race is next week - 9 days left before the submission deadline. Good luck to all.

openFoam has released an official windows version of v2.4.0, which can be downloaded at http://www.openfoam.com/products/openfoam-windows.php. It does not work with OCCFD at this stage. It is an interesting development, but also a challenging one as they are using a virtual machine in place of native port. I am not 100% sure how I can integrate it with OCCFD, but I am working on it. If anyone has experience with docker, is it possible to start a VM with specifying a list of commands to run?

I'm not an expert of open foam, as you can see, but I was wondering if OCCFD could export a working directory with all the data and the launcer needed to run a KVRC analysis with open foam 2.4 "for win".

[machin]

I would have a question for Machin (my curiosity). Is the lateral acceleration of the best cars, considering the downforce values, comparable to any real car (C group, ground effect F1, ...)?

Well the tyre model is based on an Avon A50 hillclimb compound, which is pretty soft.... I think cornering speeds (and hence lateral g-forces) are somewhere around 2012 F1 levels... Remember that we're considerably heavier than f1, so that just shows the levels of downforce are pretty good... Although there is a big spread from the top of the field to the bottom....

[CAEdevice]

I would have a question for Machin (my curiosity). Is the lateral acceleration of the best cars, considering the downforce values, comparable to any real car (C group, ground effect F1, ...)?

Well the tyre model is based on an Avon A50 hillclimb compound, which is pretty soft.... I think cornering speeds (and hence lateral g-forces) are somewhere around 2012 F1 levels... Remember that we're considerably heavier than f1, so that just shows the levels of downforce are pretty good... Although there is a big spread from the top of the field to the bottom....

Thank you. So the g forces are still "human" and realistic.

[CAEdevice]

Thanks,

interesting numbers. The low level of downforce on the JJR car is a bit surprising.
Lets hope that CAEdevice can get rid of some drag so we can have our battle to death.

I was surprised by the high drag of TF too.

[LVDH]

Yes and no.
The concept itself should not be too bad. Although I have to say I experimented with it as well and could just not make it work. Maybe next year we will see more of these kind of efforts. It would be much more elegant compared to Variante's and CAEdevice's cars.
But the TF car has these dive planes and a two element rear wing. Both create a lot of drag. Also looking at his CoP it seems that going for a less tail heavy solution will bring him quit a bit forward.
But getting the concept to work requires a Cd*A below about 0.85 which is very difficult to achieve.

Looking at my car and almost all others I still do not understand why no opening at all in my side pods helps with anything. My car is similar to JJR's car but copying anything from him just does not seem to work on mine. Well, opening the rear wheel houses like he did works (very little). Maybe I will find out what the louvers do. I have a suspicion but from my experience it will once more simply just not work for me.

[julien.decharentenay]

If you are based around Oxford, you might be interested in the following talk/lecture by Willem Toet - https://www.linkedin.com/pulse/free-pub ... eader-card

He used to be head of aerodynamics at Sauber F1.