Quote:
Originally Posted by tasdrouille
Hucho's book provide an example for this.
The back of the insight has roughly the same shape as the Mercedes C 111 III, though shorter and thicker.
On the attached image, the original shape they started with was approximately one third the lenght from the rear wheel skirt.
They tried different lenghts from 0 to 1.5 meters, beyond which there was no improvement in drag.
The function between boat tail lenght and drag reduction in this case was not linear and went up to a 25% reduction in drag.
They settled for roughly 60 cm which lead to roughly 18% in drag reduction. |
Just wanted everyone to look at the heat-exchanger outlet at the base of the windshield of the C-111.This is where Kamm did his research and for what he's famous.The radiatior air re-energized the flow over the roof and allowed it to remain attached until he arbitrarily chopped --off the rear.The flow would have otherwise stalled and separated,making the "Kamm-back" a non-starter.The C-111 windshield is also ideal ($3,000 at KIT CAR ).Hucho also says they could have lowered drag even more with extra length,even though graph does not reflect it.Great pic!