Starflight
Well-Known Member
I know the title is 'corny' but after cruising through those hundreds of sections
graciously provided by "krauss", I couldn't help wondering why the 18.3% thick
Gottingen 679 showed such a superior L/D ratio (64.8) when that number is
usually reserved for thinner airfoils. The plotted polars add up (divide that is)
and I know the Rn is low at 100000. Could any of the owners of aerodynamics
programs please run the numbers for me at R=500000, 1million and 1.5million?
The last mentioned number approximates the landing approach speed for typical
ultralights. Are there any stall problems with that section in your opinions? Thanks.
graciously provided by "krauss", I couldn't help wondering why the 18.3% thick
Gottingen 679 showed such a superior L/D ratio (64.8) when that number is
usually reserved for thinner airfoils. The plotted polars add up (divide that is)
and I know the Rn is low at 100000. Could any of the owners of aerodynamics
programs please run the numbers for me at R=500000, 1million and 1.5million?
The last mentioned number approximates the landing approach speed for typical
ultralights. Are there any stall problems with that section in your opinions? Thanks.