WB-Sails design simulation - assorted sample videos
We use computer simulation all the time, to assist our sail development & design. We run hundreds of simulations every year - here's some examples.
More animations on our YouTube channel.
Above: Flow around a gennaker running downwind. Flow starts from rest (no wind), particles are fed in a horisontal plane about at mid height and in a vertical plane at mid foot. The flow goes around the sail from all sides, to recirculate behind the sail.
Above: Flow around a gennaker running downwind. Chaotic vorticity (turbulence) behind the sail - in the very top the flow remains attached.
Above: Stress simulation of a gennaker. You can see how the sail stretches and deforms as wind is increased. Red areas highlight lots of loading, blue colors little. You can see the effect of corner patches. AWA 122°, AWS from 0 to 18 kn.
Above: Another stress simulation, at a slower pace. The simulation shows clearly how the luff around the corners is much more highly loaded than the leech.
Above: Motions of a Star boat sailing in 35 cm high waves. Pitching, steering, heaving (vertical motion), rolling, and even the crew motions can be simulated. The motions are measured on board with a device called IMU (inertial motion unit), made by Cosworth and similar to the one used for monitoring G-forces on Formula 1 racing cars. The simulation can be used for studying the effects of different wave driving techniques, in addition to the aero-work. Note how the bow follows and elliptical path with a longer axis more or less vertical.
Above: Effects of the boat motion on flow over the sails.
Bad air behind a Finn sailing upwind in TWS 15 kn.