Don't tell this to the guy who won sports class nationals last year in a
standard Libelle. He may have a differing opinion!!!

Brian

"tango4" wrote in message
...
K8's, PW5's and Libelles don't 'penetrate' well because flying fast just
brings 'em down faster. Going cross country in anything but a gentle
breeze
becomes seriously hard work.

ASW27's full of H2O penetrate like darts. You can get round the task with
20kt breezes on the nose all day.

I suppose it relates to how flat the polar curve is above 100 kph.


Ian


"Shawn Curry" wrote in message
link.net...
Bruce Greeff wrote:
Hi

I was recently challenged to define Penetration.
We failed to find a suitable definition - although I have my own
opinions.

Views presented on the subject include:
Glider penetration is represented by the polar curve.
Penetration is proportional to wing loading.
Penetration is the "real world L/D" taking into account the energy
reserves over drag to overcome upsets caused by turbulence etc.
Penetration is related to weight only. (variant ratio of- weight and
frontal area * Coefficient of Drag)

I know we must be missing the point so -
Any takers from our learned aerodynamicist types?

What exactly is "penetration" as applied to gliders and how does it
differ from the polar curve.

In the glider sense at least:
Being able to go fast and still keep it up.
Hope this helps.

Cheers,
Shawn