Instationary aeroelastic computation of yacht sails

E3ective schemes exist to calculate aerodynamic forces for thin bodies and structural dynamics of 7exible membranes. The 7uid dynamic of thin wings in a irrotational 7ow leads to the lifting surface theory. Neglecting the inertia of the membrane the structural dynamics are solved by the non-linear ;nite element method (FEM). But the interaction of 7exible membranes and an irrotational 7ow causes problems dueto thedi3e rent natureof themathe matical equations. On theonehand, thereis a partial di3erential equation for the structural dynamics and on the other hand, there is a singular integral equation for the aerodynamics. The numerical discretization scheme has to ;t these di3erent types of equation. Our work introduces a new interaction scheme to couple the singular integral equation of the lifting surface theory with the non-linear FEM of the membrane static. The fundamental examinations, showed by Schoop et al. (International Journal for Numerical Methods in Engineering 1998; 41:217–219), are applied to realistic sail geometries and the aerodynamics is extended to instationary 7ow conditions