Frequency-Domain Lifting-Line Aerodynamic Modelling for Wing Aeroelasticity

A frequency-domain lifting-line solution algorithm for the prediction of unsteady aerodynamics wings is presented. The Biot–Savart law applied to determine normalwash generated by wake vorticity distribution, whereas steady and airfoil theories (Glauert’s Theodorsen’s, respectively) are used evaluate sectional aerodynamic loads, namely lift pitching moment. released at trailing edge derives from bound circulation through Kutta condition convected downstream with velocity undisturbed flow. local obtained application Kutta–Joukowski theorem, extended flows. Assuming a bending torsion wing, this paper provides matrix transfer functions, relating generalised loads Lagrangian coordinates elastic deformation. Its rational approximation yields reduced-order state-space model suitable an aeroelastic stability analysis control purposes. numerical investigation examines influence both shed/trailed modelling different approximations theorem flows on functions given developed solver. accuracy solver assessed comparison predictions three-dimensional boundary-element-method potential It shown that, least frequency range considered, regardless applied, formulation based Theodorsen theory that in very good agreement results boundary element method slender wing. This worsens as wing aspect ratio decreases. lower level Glauert theory. In case, more sensitive express