Foilstate

Very interesting publication about sinusoidal leading-edge on foils.. 👀 Kujira front wing whale like tubercules probably have a significant effect on the foil’s behavior, making the coefficient of lift more homogenous across all angles of attack, plus a softened and delayed stall.

The paper is called “Effect of Bio-Inspired Sinusoidal Leading-Edges on Wings” (2018), manuscript in free access online. In the conclusion :
“The stall characteristics for all of the models with modified leading-edges did not exhibit a dramatic, sudden loss in lift, but a more gradual, almost plateau of CLmax before a very gradual loss in lift. Although the sinusoidal leading-edge models do not have as high of a CLmax and CL is comparable or lower for most of the angles of attack up to 16°, the presence of the tubercles softens and delays stall. Additionally, after 16°, the sinusoidal leading-edge model exhibits a higher CL, as much as 25%. This gives the sinusoidal leading-edge design an expanded operating envelope of higher lift at higher angles of attack.”