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Old 10-06-2022, 11:30 AM   #11 (permalink)
aerohead
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'data'

Quote:
Originally Posted by wouterremmerie View Post
Hi Aerohead,

no, we use a finite volume method:
this has been the default method for decades, although I do believe LBM could be (one of) the winning methods for the future.

Regarding drag values:
without discrediting the manufacurers, the claimed values are usually fairly optimistic (as they sometimes play with ride heights, rims, aircon settings, etc during testing).

We performed an independent validation on a Tesla Model Y together with one of our partners - our Cd value was less than 6% off compared to the measured value. And qualitative data (the flow structure behind the car) also showed good correlation:
airshaper.com/blog/tesla-model-y-aerodynamic-benchmarking

I would agree drag hasn't increased by 14%, so it's likely more a matter of comparing the right data here. Data coming from different sources and/or different measuring techniques (tunnel vs simulation) can blur the whole story.
Thanks!
My single brain cell activated, and it struck me that Ford Motor Company would be required to publish a 'crosswind-averaged' drag coefficient for EPA ( maybe ISO ) certification.
Some of the discrepancy between data may be wrapped up this manner in the 'way' they're required to report.
The qualitative 'trends' DO appear to be spot-on!
Thanks again!

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