Hello Everybody,
Span efficiency factor appears in the lifting-line theory of Prandtl describing Lift and vortex drag of a finite wing. According to this theory, the most efficient wing is an elliptical one and, roughly speaking, the span efficiency factor defines an efficiency of a given wing planform relatively to elliptic wing.
In the framework of the lifting line theory the span efficiency cannot exceed 1.
My question is: can this efficiency factor be more than 1, when going beyound lifting-line approximation ? (assuming that induced drag remains to be proportional to square of lift in less rudimentary theories). In other words, does it exist such a wing whose induced drag is less than that of elliptic wing in the lifting-line theory (provided aspect ratios and lift coefficients are the same and viscous effects are neglected).
Thanks
Truffaldino
Span efficiency factor appears in the lifting-line theory of Prandtl describing Lift and vortex drag of a finite wing. According to this theory, the most efficient wing is an elliptical one and, roughly speaking, the span efficiency factor defines an efficiency of a given wing planform relatively to elliptic wing.
In the framework of the lifting line theory the span efficiency cannot exceed 1.
My question is: can this efficiency factor be more than 1, when going beyound lifting-line approximation ? (assuming that induced drag remains to be proportional to square of lift in less rudimentary theories). In other words, does it exist such a wing whose induced drag is less than that of elliptic wing in the lifting-line theory (provided aspect ratios and lift coefficients are the same and viscous effects are neglected).
Thanks
Truffaldino
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