Experimental and numerical performance evaluation of the Olympic windsurfing class iQFOiL

This work presents an experimental and numerical assessment of the hydrodynamic performance of the Olympic iQFOiL windsurfing class. Full-scale towing-tank tests were carried out at velocities between 3.0 and 7.0 m/s and at angles of attack from −1° to 4°, providing benchmark measurements of lift and drag forces. Preliminary Computational Fluid Dynamics (CFD) analyses revealed that Fluid Structure Interaction (FSI) effects needed to be included to achieve accurate predictions and good agreement with the experimental data. Numerical simulations were therefore performed over the velocity range 1–7 m/s at zero angle of attack. A parametric Computer Aided Design (CAD) model was developed to generate both the undeformed geometry and the deformed configurations obtained through Finite Element Method (FEM) structural analyses. The numerical campaign enabled a detailed investigation of pressure distributions and structural deflections, indicating negligible deformation up to 4 m/s. At higher velocities, neglecting hydroelasticity resulted in a noticeable underestimation of lift. The analysis of the velocity and pressure fields for the undeformed and deformed shapes provided an enhanced understanding of the behaviour of the iQFOiL, particularly in terms of the effective trim angle and the relative variation in the longitudinal position of the centre of pressure.