Quote:
Originally Posted by Phase
What’s the explanation for the front car benefitting? Filling in the wake behind it? Increasing air pressure behind leading car?
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The wake itself has a drag of Cd 0.0945.
When the second car rides the rear bumper, the lead car essentially loses it's wake. ( Cd 0.315 - 0.0945 = Cd 0.2205 )
In the two-car NASCAR draft, the two vehicles become an aerodynamic singularity, sharing one frontal area. The lead car no longer has a 'base.'
The trailing car has no dynamic pressure acting on it, except at it's windshield.
Wetted area of the trailing car is 'invalid', as it's immersed within the thickening turbulent boundary layer which behaves differently from the laminar flow of the lead car.
Base pressure is transferred completely to the trailing car.