louvers & aero?

[proxlamus©]

its been snowing really bad down here in CO so I tried an experiment..

 

I just cleaned off my windshield and packed alot of snow on the Z.. I went for a quick spurt to about 60mph and watched the snow powder blowing off (like smoke in a wind tunnel)

 

I noticed that the snow was actually going UP the rear window with the louvers on.. which probably explains why the louvers lift up in the air at high speeds if not bolted down.

 

I also noticed the airflow over the roof of the car blew off just enough snow to barely let the vortex generator peak up above the snow level. and I mean BARELY.

 

What does this tell me?! The boundary layer and airflow on the Z is too high above the roof line to help with the vortex generators. The VG's will only get a minimal airflow.. Keep in mind the snow packed on the roof can dramatically change the aerodynamics.. I was just hoping high speed air would blow the snow off the car and follow the lines of the car which isnt always true in this case.

[JMortensen]

I wouldn't draw any conclusions from your test at all. I think it's probably safe to say that the louvers have a much greater aero effect than the VG's just based on size, and it's probably also safe to say that testing aero with snow is a bad idea. Above and beyond that expecting anything meaningful is probably not being realistic.

[proxlamus©]

the only thing I can conclude.. is I know the louvers build lift at high speeds... the airflow flowing UP the rear hatch from the low pressure, and everyday observations on a dry clear day, the louvers do lift at high speeds.

 

 

The snow observation was just for kicks, however due to the loose, coarse surface from the snow and ice, generated tons of drag and altered the aerodynamics of the car rather dramatically.

 

All i can say is louvers do lift at high speeds, which means pressure drops due to the louver design.