Jersey Tom wrote:
Mystery Steve wrote:And CFD is... engineering. It isn't perfect, either. Like richard said, it is useful for doing design iterations, but the data is dubious if you don't verify it in the tunnel. It absolutely makes sense to produce the model to verify the CFD data.
This is a very good point that people should pay attention to.
I think a lot of people have the misconception that CFD, FEA, tire data, and vehicle simulation are all super accurate. They aren't. It's all incredibly sensitive to how its set up. Can be crap just as much as it can be gold.
Everything needs to be validated. Simple models make it much easier.
I´d like to make a point here .I´m working in Automotive business and happen to
work in an area where aero is also a factor .So of course there are CFD and Aerodynamic testing in the tunnel day after day.
Is there correlation to what we see in the actual car? yes ,air is flowing ...,but
really I do have massive doubts the results we get are really of big value.
You don´t get real data you could rely on. Everytime some sort of fudge factor is
needed to match the numbers with real world.The guys get very slippery when you try to nail them down on their findings and at the beginning of the project theres no calculated data it is only a scaled data from previous car.
So in my view the whole story is really reducing to just how experienced and all encompassing the dicisiontakers are .You may iterate towards infinity with CFD if you just miss one factor all your results are worthless or may even lead into directions contracticting actual needs.
You don´t need to correlate CFD to tunnel ,both only simulate real world.You need to correlate both to the actual car!Only then you are sure you are not developing rubbish .Stopwatch does not lie.
As my personal experience in Racing I do know quite well how to get tyres in their
operating window and keep them there I make allowances for all kind of stuff in preparation for the next set to be used.Most of the time nowadays I´m spot on with my preparations but honestly speaking I have no clue how to put all this into a formula so some unexperienced newbie stands any chance to make this work at the track .There are so many factors to consider ,with the driver and driver confidence level just two impossible to quantify that I have doubts how this could possibly fit into a excel sheet producing sensible results...