Effect of weight on the Polar

[Pawnee Pilot[_2_]]

If I have 2 polars for the same glider, say at 28kg/m2 vs 43kg/m2,
the polar for the heavier glider is displaced to the right and down.
Applying the square root of the ratio of the wing loading, ie sqrt
(43/28), would give the higher speed for the increased loading, what
is displacing the polar down? Is it just the additional profile drag
at the higher speed?

[mattm[_2_]]

On Oct 15, 5:55*pm, Pawnee Pilot > wrote:
> If I have 2 polars for *the same glider, say at 28kg/m2 vs 43kg/m2,
> the polar for the heavier glider is displaced to the right and down.
> Applying the square root of the ratio of the wing loading, ie sqrt
> (43/28), would give the higher speed for the increased loading, what
> is displacing the polar down? Is it just the additional profile drag
> at the higher speed?

No, I believe it's the higher induced drag since you have to fly at a
higher angle of attack to generate more lift of offset the wing
loading.
To see exactly what it does to the polar multiply the x and y value
for each point by sqrt(w1/w0). At higher speeds the actual sink
rate should be less -- this is the advantage that ballast gives you.

-- Matt