FSI Analysis

Fluid Structure Interaction is a scientific simulation method to optimize the sail design and consequently the performance.

The analysis is made in a comprehensive sail design solution that has been developed over years and validated by real scale experiments. This methodology is very often used in projects within the super yacht and grand prix racing segments. For one off projects the method is a must and essential to obtain an acceptable starting point for the sail designs and later on setting up the boat according to the desired sail shapes and target values for boat speeds and angles.  Naturally everything possible from those studies will eventually be applied to general sail development.

“At Elvstrøm Sails this is in fact an ongoing process in developing our competencies and staying at the cutting edge of modern sail design”, R&D Director Jesper Bank explains.


Any structural analysis starts with a field of forces applied on the sails surface. In a simulated sailing condition with a predicted boat speed, True Wind Direction (TWS) and True Wind Speed (TWS), the characteristics of the boat and the initial sail trim, the FSI calculation delivers a vast amount of essential and critical information in order to obtain the most efficient flying shape of the sail.

“From my point of view this is an excellent tool in sail making to get in-depth knowledge on flying shape, pressure distribution, loads and strains among others. To us as sail designers that is essential in designing the optimal sail. As a professional sailor I have spent endless hours on defining the way we want to be sailing the boats and combining this with the boat and rig characteristics. This would lead us to discussing sails shapes with sail designers, who can transform our wishes into flying shapes. This way of working could pull you ahead of competition,” Jesper Bank concludes.