Khamsin Virtual Racecar Challenge 2014

[julien.decharentenay]

Thanks for participating in this second race. CFD results have been coming through slowly. There has been a small addition to the results page - which may not be obvious. On the result page, go to the 3D Views section. The images are now link that take you to an online 3D viewer where you can pan, rotate, zoom in and out and load various items (geometry, streamlines, cuts, and surface shear vectors). A screenshot of the viewer is shown below.

Important note:
1) Do not try loading the pressure map (visualisation of pressure on the surface of the car) as the data is typically between 100MB and 150MB and will take a very long time to load... I will work on this for the next race;
2) The data is typically loaded when required (each cut is a bit of data for example). It is loaded the first time and then is kept in memory. So be patient on the first loading. I will be altering the way this is done for next race and will hopefully improve on this aspect;
3) It is a bit CPU and memory intensive.
4) Some of the earlier run may have issue with their geometry being truncated. This was fixed at later date. Let me know if you were one of the unlucky one and would like to have it fixed.

[CAEdevice]

Hi, I have a request for Machin: would it be possible to have Monza charts pictures with bigger dimensions and more detailed axis (es. CI.A 1.0-1.5-2.0-2.5-3.0)?

[machin]

Yes, I will add some more information to the charts to make it easier to decide what set-up to aim for with your cars for each race.

[CAEdevice]

Yes, I will add some more information to the charts to make it easier to decide what set-up to aim for with your cars for each race.

Thank you!

[machin]

OK, so the first chart below shows the Cd.A and Cl.A figures of all the cars raced so far (this year and last). The blue curve represents the best Cl.A figure for each value of Cd.A achieved so far between Cd.A = 1 and Cd.A = 1.45. I've called it the "Best limit" curve.



Now, I've added this "Best Limit" curve to the Magny Cours chart, below. what this says it that if we tested all the different cars again (with COP adjusted so it equals the perfect 1.83m), the fastest car would be one having a Cd.A of 1.16 and a Cl.A of -2.5. Of course, a car having a Cd.A of 1 and a Cl.A of -3 would be even quicker... but none of you have built a car with that level of aerodynamic efficiency (yet!).



And below I've added the same "Best Limit" curve to the Monza chart. Again, what this says it that if we tested all the different cars again (with COP adjusted so it equals the perfect 1.83m), the fastest car would be one having a Cd.A of 1.08 and a Cl.A of -2.3. Again, a car having a Cd.A of 1 and a Cl.A of -3 would be even quicker... if you can design one!




Remember the charts above all assume you have COP=1.83m (which is a perfectly "balanced" design). If you don't achieve the correct balance your car will be slower than the charts indicate; "Downforce is nothing without Balance!"

I hope that helps everyone to determine what set-up they should be going for....

[machin]

And... for completeness I have added the "Best Limit" curve to the Monaco chart too, which shows that the fastest car of all the ones created so far would simply be the one with the highest downforce (and a good balance!)

[CAEdevice]

Thank you Machin! The charts are very interesting... now I know how far my car is from the "best limit"

If possibile, it will be useful to have a Monza chart with more isolines of Cl.A, like the last one (Monaco) you published above, but with more Cl.A values (es. from -1.0 to -3.0 with a step of 0,5m. It woould be great to have a bigger picture (es. 880x600) and a more detalied time axis (step 0,5s).

[machin]

Do you think you will gain much from a higher resolution chart?

For example, here I have plotted your Monaco 2014 result onto the Monza chart:-



Which would say that if you have a good balance your lap time should be around 1:27.7 (That is half way between 1:28.1 and 1:27.3 as indicated by the location of the red circle on the chart). In order to compete with the fastest cars you will need to increase downforce by 25%, and also decrease drag by 16% to get down to 1:25.5 lap time. I'm not sure that having a higher resolution chart will really tell you much more than that?

[CAEdevice]

You are right, it just would be easier to draw my lines over it with MS Paint
Thank you anyway for the "personalised" analysis.

[astracrazy]

Two graphs I will be posting on here and keeping up to date on the standings page. I thought it would be kwl to see how things progress

[CAEdevice]

Great idea! I like the new graphs.

PS: I was wondering: any news from Kulcu?

[astracrazy]

not yet. But as its pay per race he could take part in the last 3, he could take part in the last 1. Its up to him/her

i thought the graphs would be a good visualisation of how things pan out

[julien.decharentenay]

Just a brief word to say that astracrazy is doing a great job. From my side, I am still struggling with the online 3D viewer that I mentioned earlier. I changed the approach for the last couple of cars, but the altered method is worth. I have something that I hope will be better, but it will only be available for the next race...

[machin]

I thought it would be kwl to see how things progress

Yeah, it should be interesting... I'll also update the Cl.A vs Cd.A scatter plot to see how the designs of the cars progress after each race.

[astracrazy]

results are up.

some keen eyes would of seen the results yesterday as i have just found out google updates the graph images.....oops