The Oswald efficiency factor, often denoted as “e,” is a dimensionless parameter used in aerodynamics to characterize the efficiency of an aircraft’s wings in generating lift while minimizing drag. It is named after the German aerodynamicist Hans Wolfgang Oswald, who contributed to the understanding of wing efficiency and drag. The Oswald efficiency factor quantifies how closely an aircraft’s lift distribution matches that of an idealized elliptical wing.Â
- e is the Oswald efficiency factor.
- δ is the induced drag factor.