Computational investigation of variation in wing aerodynamic load under effect of aeroelastic deformations

Abstract

The evaluation of the variation in aerodynamic load on a wing under the effect of elastic deformations requires solving the problem of wing deformation when wings are subjected to distributed aerodynamic load. This paper presents the calculation of coupling the aeroelastic system for 3D wings. The aerodynamic problem was solved by the doublet–source method for 3D wings, with wing thickness considered. The problem of elastic deformation was solved by the finite element method for hollow 3D wings, with beams arranged inside. Results concerning aerodynamic load on the wing were considered input parameters for the calculation concerning the problem of wing deformation, and those about the deformed wing geometry were deemed input parameters for the calculation regarding the problem of wing aerodynamics for the second calculation. The calculations concerning these problems were repeated until the wing twist angle converged. Analyses and comparisons were performed on the distributions of aerodynamic loads on the rigid and deformed wings to examine the change of the aerodynamic load depending on the structure (aerodynamic loads being functions of the external geometry of the wing, the incidence angle, and the velocity at infinity are solutions of the pure aerodynamic problem). Results regarding wing twists and stress distributions for hollow wings with and without beams inside were presented to assess the cause of changes in aerodynamic load and wing static durability. Aeroelastic calculations were formulated with different velocities at infinity to indicate the need for a suitable structural solution when the aerodynamic load is expected to reach a high value.