Creates a 3-dimensional sail mold.
Spiral initially defines the sail's three-dimensional shape as a ‘molded' surface without any wind pressure or load applied. Precise control over all aspects of a sail's shape allows a broad range of mainsails, genoas, jibs and asymmetric spinnakers to be designed. Every dimensional aspect of the sail can be adjusted both in horizontal and vertical axes.
Rig and sail CAD modeling.
Desman creates a complete rig/sail model in a three-dimensional environment. In Desman, North designers can specify mast size, rigging position, rigging attachment points at the deck and trimming locations. The modeled sail/rig system incorporates the mechanical properties of the spars, standing rigging, running rigging and sails in terms of moments of inertia, sail and spar surface area, materials stiffness and resistance to stretch. Later in the process, Membrain (described later) uses the Desman model to determine deformation under load for the sail and every piece of standing and running rigging, right down to stretch in the sheets and halyards.
Defines the structure of a sail.
3D Layout is used to define the structure of a sail in terms of yarn layouts, panel layouts, tape layouts, yarn density, and/or film types. Output from 3D Layout is used to shape 3DL molds or provide seam curves for paneled sails. All yarns are plotted in the same 3-dimensional space they will assume when sailing. 3D shapes are translated into panel layouts for downwind sails. 3D Layout also has powerful analytical tools which can be used independently or in conjunction with Membrain.
Applies wind pressure to 3-dimensional sail mold and provides sail forces.
Using Flow, wind pressure is introduced over the sail's three-dimensional “mold” to produce a pressure field on the sail's surface. The pressure varies over the surfaces based on the size and shape of the sail and the strength and direction of the air flow. The resulting pressure field is then linked directly to Membrain for finite element analysis. Flow also reports the drive and moments developed by sails, which can later be used by either the North Sails VPP or other VPPs for sail performance analysis.
Balances wind pressure, sail shape and rig forces.
Membrain takes the sail/rig model from Desman and applies pressure fields from Flow, deforming the mast and sail as a single unified structure. As the sail/rig structure is deformed, the shape of the sail changes, so Membrain then links back to Flow to acquire new pressure fields for the deformed surface. This changes the sail shape in Membrain yet again, so the process is repeated until there is stable balance between pressure and rig/sail deformation. Membrain can be used to test sail shapes, optimize mast design and rig tune, create sail shapes to test in North VPP, check loads for designers, and more.
Membrain applies pressure to the integrated rig/sail system and then iterates the results back to Flow until pressure and sail deformation achieves a stable balance
Compares actual sail shapes to Membrain predicted sail shapes where possible.
SailScan II analyzes photographs of sail shapes taken on-the-water and then compares these shapes to the original design file. SailScan II is a valuable tool for determining if a sail needs shape adjustments after a specific period of time. It also aids North sail engineers and production specialists in refining production and simulation methods toward improving the competitive life of North sails.
Virtual Wind TunnelTM
Models air flow on upwind and downwind sails.
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 (University of Auckland 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.
Measures effects of sail or rig adjustments on rating.
Understanding how adjustments in sail shape affect speed is only part of optimizing a boat's performance. Race Model allows North designers to account for changes in rating from one test configuration to another. The Race Model can predict which configuration will win in a handicap race over various courses.
Regression analysis to calculate hull forces without existing hull data.
SPP (Sail Performance Prediction) is used to predict relative sail performance between different sail designs or trims quickly. Using SPP, designers can instantly compare the performance of a new sail design relative to a baseline m