Dimples

[Cd]

The dimpling that I saw on the VW was on the underside of the rocker panel, just behind the front wheels. It was made of plastic. I can't imagine how that this could stiffen anything other than the plastic rocker panel. ( "confused")

A while back, someone here posted some pictures of either a BMW or Audi that also had dimpling on the bottom of the car, as well as NACA ducting.

I looked at the underside of an LS430 but could not see the 'dimples' very well. They appear to also be on a plastic piece located around the engine cover ( " bellypan" )

Off topic : Used car lots are great for seeing things like this. No one will shoot you for snooping under their car. ( I also found out this way that the VW Passat has a beautifully designed engine cover complete with 3 or 4 NACA ducts. The new Fit has a smaller more sloppy version, but also has small NACA ducts at the rear or the cover as well.

[aerohead]

Originally Posted by Cd

The dimpling that I saw on the VW was on the underside of the rocker panel, just behind the front wheels. It was made of plastic. I can't imagine how that this could stiffen anything other than the plastic rocker panel. ( "confused")

A while back, someone here posted some pictures of either a BMW or Audi that also had dimpling on the bottom of the car, as well as NACA ducting.

I looked at the underside of an LS430 but could not see the 'dimples' very well. They appear to also be on a plastic piece located around the engine cover ( " bellypan" )

Off topic : Used car lots are great for seeing things like this. No one will shoot you for snooping under their car. ( I also found out this way that the VW Passat has a beautifully designed engine cover complete with 3 or 4 NACA ducts. The new Fit has a smaller more sloppy version, but also has small NACA ducts at the rear or the cover as well.

Any flat surface can behave like a diaphram.A drumhead would be an example.All such surfaces have a resonant frequency.Certain frequencies from an electric guitar will cause a snare-drum to "sing",and other drum heads to "go off",and you'll see amplifiers and monitor speakers placed in front of the drum set,projecting the sound away from the drums to attenuate this resonance.------------------ The floor of a car can do the same thing when exposed to certain engine rpms and loads.To prevent noise,vibration,and harshness,automotive engineers will "distress" a panel surface to alter it's natural frequency,moving it to that which will not be encountered during normal operation.---------------- The deformation can also increase span-wise bending strength for a given wall thickness of material,allowing thinner,lighter material to be used.--------------- An I-Beam or Truss would be examples of very light structures of immense strength.