Comparative Analysis of Wind Load Application Techniques for Aeroelastic Analysis of Hard Wingsails

Abstract Reliability analysis of mechanical systems requires precise evaluation of structural responses in critical components. In aeroelastic analysis, the fidelity of these responses depends on accurate modeling and transfer of aerodynamic loads between fluid solvers and structural solvers. Although several CFD-to-FE load transfer methods exist, comparative assessments for wingsail structures remain limited. This study investigates the aeroelastic response of hard wingsail components using three aerodynamic load transfer methods, assessing both structural response predictions and computational time. The first method uses a Lifting-line method, transferring aerodynamic loads directly to the lifting-line. The second is a panel-based method based on the 3D vortex lattice model, integrating CFD and structural mechanics via the DLOAD subroutine in Abaqus v2023. The third is similar but uses a field-mapping technique for load transfer. These methods are evaluated for single-element and two-element wingsails. Aerodynamic pressure coefficients for the single-element configuration are obtained using XFOIL 6.99; experimental data inform the two-element wingsail. Results indicate that the lifting-line method predicts higher von Mises stress in the root region of the main load-bearing steel component, but lower stresses in the core and face-sheet regions of the leading-edge sandwich composite. Structural stresses in the root regions of the leading edge and spar-box components of the wingsail obtained using the DLOAD subroutine strongly agree with the mapped field method. However, the DLOAD subroutine demonstrates superior computational speed, requiring approximately 30% less wall-clock time than the mapped field method at higher core counts, while maintaining nearly equivalent deformation predictions. Keywords wingsail; lifting-line method; vortex lattice method; field mapping; DLOAD subroutine; finite element analysis; wind-assisted propulsion