Quote:
Originally Posted by Phase
my understanding is you want a mellow enough tail that gets smaller and smaller while maintaining flow attachment, try to reduce the wake size as much as possible, then detach the flow as fast as possible with hard edges. using small lip spoilers can help recover pressure too when it flips off the trailing edge
look at the mercedez eqxx , the light year zero, and and even a little bit of the vw xl1 car. they all have tear drop rears that then curve up/flatten out for a few inches at the rear for pressure recovery. the original honda insight did not have the mini rear spoiler shapes. it just dropped off. im assuming thats because engineers didnt know as much back at the time of development, and why its drag cd is 0.25 even with a flat bottom and rear fender skirts
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By the time they designed the Insight, HONDA R&D had already produced Cd 0.10 solar race cars, so they 'CLEARLY' understand low drag.
The Cd 0.25, measured at Honda has never been demonstrated to be 'incorrect'.
International, inter-tunnel, Cd variability is a 'ground-proven' fact.
And it doesn't matter in the grand scheme of things.
The Cd 0.30, as measured at A2 can be simply intuited in the context of a full-scale wind tunnel blockage-ratio calibration model.
As far as I'm concerned, it remains Cd 0.25. It's all 'conditional' , 'contextual.'