VIRTUAL WIND TUNNEL™ ...models air flow at 100% scale

Virtual Wind Tunnel (VWT), was originally developed jointly by Dartmouth College Thayer School of Engineering and North Sails and is now run by the Stevens Institute of Technology. VWT is the first (and still the only) computer simulator to accurately model wind flow on downwind sails at 100% scale. When first developed, North Sails used the world’s two leading low-speed wind tunnels (North’s own Twisted Flow Wind Tunnel and Oracle’s IACC Twisted Flow Wind Tunnel) to verify it’s accuracy. The results have given us great confidence that North’s “VWT” predicts results with more accuracy than wind tunnel sail testing of any kind. VWT provides powerful insight into flying sail shape, sail drive, shape stability and ease of trim.

Unique to VWT is its ability to integrate with Membrain allowing both upwind and downwind sail shapes to be analyzed with unprecedented accuracy.
Virtual Wind Tunnel run of a Ker 39 medium jib and main showing detailed analysis of the hull and sailplan interaction.© North Sails
Analysis refining the upper shape of a J2 jib studying air flow around leech. Note that headstay and mast are included in the model.© North Sails
Pressure coefficients used to refine sail shape on A1 asymmetric spinnaker. Note smooth elliptical pressure profile indicating an efficient distribution of loads.© North Sails