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Old 02-17-2024, 11:42 AM   #14 (permalink)
aerohead
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' taping over the gap '

Quote:
Originally Posted by Phase View Post
Taping over the gap increase drag? I’m confused
1) On the Golf-I, the roofline was not 'aerodynamic', as designed by ItalDesign, and prone to Cd 0.48.
2) Hucho et al. investigated 'BandAids' for the Beetle's replacement, in their new wind tunnel.
3) They achieved Cd 0.34 using a 'template' roofline, but that was shot down in committee because it didn't 'look' like the ItalDesign car ( which is a legal requirement between a contracting manufacturer and designer ).
4) 'Taping' the rear hatch roof gap was one of the things they tried in the pursuit of a lower Cd, but discovered that the gap was producing a lower drag 'squareback' wake, compared to a higher drag pseudo-Jaray wake of 'small', but low-pressure/ high drag/ high lift ( exactly as VW-Porsche found on the 1972 911 Carrera RS 2.7, 'Pete' Brock with the Shelby Cobra Daytona Coupe, and Bob Lutz with the Dodge Viper Coupe ).
5) So, by leaving the gap open, they were allowed to get from Cd 0.48, down to Cd 0.43, for the 'final' production shape.
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