Quote:
Originally Posted by Phase
Snow melted. Here’s how the dirt deposited. Wonder what this says about pressure too in the rear.
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Closely-spaced streamlines mean high-velocity, low pressure.
Widely-spaced streamlines mean low-velocity, high pressure.
The base pressure is determined by the pressure at the separation line.
The only way to 'raise' the pressure is by elongating the body along a streamlined path, which produces the pressure recovery as the streamlines decelerate, trading velocity for static pressure.
( if you've seen the 'blue' wind tunnel smoke-flow image of the VW XL1, you'll see how the streamlines are 'wide' at the very back of the car. This is why it's Cd 0.189 ).
Same for M-B IAA.
M-B EQXX.
It's also why the car doesn't have rear lift and doesn't have a rear spoiler, and is stable at 112-mph.