Hi,
I am back with some final numbers on the CFD mesh and some pictures as well.
The mesh size depends on whether the surface is the front or rear wings or the remaining of the car. At the front & rear wing, the mesh size is approximately 4mm with 2 prism layers of ~1.2mm. The remaining of the car has a mesh size of ~8mm with 2 prism layers of ~2.4mm. The mesh size is set to be constant in the area (i.e no variation between 2 different mesh sizes). Overall the cell count is expected to increase from approximately 900,000 cells last year to around 2,600,000 cells. As shown on the picture, there may still be issues with separate wing elements getting merged.
See images of the front and rear wings mesh:
The domain uses a coarser mesh away from the car, with a refinement box extended downwards 1 car length. See screenshots:
A few more details, the modelling is using the full car, not the half car. I tried using the half car approach and found that the intersection of the symmetry plane with the car body could result in bad cells and therefore reverted back to the full car approach.
Cost wise: I spent a lot of time trying to improve on turn-around time and therefore cost and managed to keep it down. So Luke and I have reduced participation cost to AU$20 for the challenge (5 races).
Portal: As Luke mentioned, I spent some time working on a submission portal (in the same spirit as Aerodynamic on Demand). It can be used to generate the openFoam setup as per the challenge setup, which you can download and use to run the openFoam CFD simulation locally. Even if you are not planning to run the full CFD model in openFoam, use it to make sure that the mesh is not closing off front or rear wing elements.
At this stage, there is no documentation on how to use it (particularly how to prepare the geometry for it). I will be setting up a video-conference using Google Hangout on Air to discuss how it works and you can ask me for input on making it work for you. I am proposing this coming Saturday
http://www.timeanddate.com/worldclock/f ... p1=47&ah=1. Don't worry if the time is not suitable as a video recording will be available on YouTube afterwards - just that if no-one is coming, I won't have much to discuss... Bare in mind that this is still relatively recent and that there will be some teething issues.
The portal address is:
https://cfdcloudengine.appspot.com/, select Start Calculator under Vehicle Aerodynamic Study. The velocity is 44.7m/s and the yaw angle is 0 degree. Once submitted, you should receive an email with a link to the openFoam case setup.
Geometry: upload it in STL format (or an archive of multiple STL files) that is exported in meters...
