Case studies

FSI-coupling of a sailboat

Predicting sail and rigging stresses and deformation by fluid-structure-interaction (FSI) coupling of a sail deformed by the wind.

Edwin Lamers
Professional Expert
FSI-coupling of a sailboat

Getting a grip on sailboats

Sailboats are exposed to diverse and extreme wind conditions. To determine the stresses and shape of the sail it is practically impossible to test every scenario in real life. When questioning the impact of wind speed, rigging pre-tension, sail material and/or boat design, virtual testing is the answer.

left: modelled geometry, right: pressure on the sail due to the forces exerted by the wind

Finding the balance

The forces exerted by the wind and the shape of the sail are closely linked. This imposes a challenge, because everything on the boat is deformable: the sail and rigging stretch, and the mast, gaff and boom bend. A fluid-structure-interaction (FSI) coupling offers the solution.

An analysis on a Valk has been performed in close cooperation with Van Oossanen, whom provided the geometry of the Valk and its sails. The air flow was modelled using a potential flow solver, and together with the mechanical (finite element) model, pressure and deformation data is continuously exchanged, untill a steady-state solution is obtained.

The last link: the real world

The last step is to build our confidence in the model, which is provided in the form of experiments in cooperation with our partners in the RoSF project. The sails material was tested at NHL Stenden, providing the required input for the material modelling in the mechanical domain. The resulting sail deformation has been validated with 3D optical measurements by Hanze (Lidar), on a Valk provided by Molenaar at the Workumer Jachthaven.


More about our work

For further details on this case or a demo of the model and its findings, please contact us on <nobr>+31 (0) 88 5202 500</nobr> We're more than happy to share our knowledge and expertise.

info@reden.nlCall: +31 (0) 88 5202 500