Duotone NOW Magazine No.03 2022

Flow simulation and flow analysis are essential for any object moving through air or water efficiently: a racing car, a boat or a kite foil. With iXent, Duotone has teamed up with internationally sought- after experts in the field. The company has great experience in the development of lightweight, high- performance structures for the automotive world, the international sailing scene as well as other racing sports such as bobsleigh. They bring essential manufacturing know-how to the table, especially in the field of composite materials.  For the development of the Duotone Foils, iXent uses these same computational methods as the Automotive and Aerospace industry: CFD* and other Aero /Hydro tools target the optimization of drag, but also help to keep an eye on lift coefficients. Finite Element Analysis* at the same time ensures the structure withstands the loads it is exposed to as well as the deformation considerations needed. “With the use of these modern research and development methods in the area of Aero /  Hydrodynamics* and Structural Analysis it is possible to design foils in a more efficient, specific and sustainable way“ Leopold Fricke, an engineer at iXent, says. The reason: Computational methods enable you to model a physical problem on a computer. It is possible to analyze small and major changes to a product and evaluate the change in performance without the need for a physical prototype. “Usually it would take two to three months to have a prototype ready to compare the changes made to the former model. Sometimes only to realize the updates do not work the way you hoped they might” Leopold tells us. Simulating these changes and analysing the outcomes on the computer saves a lot of time. Only a small number of prototypes are necessary to validate the findings before kicking off the production. “Now the biggest challenge is to analyse and define precisely which attributes in the wing the client is looking for,” Leopold says. “Things like pitch stability or lightweight construction are relatively easy to achieve. In the simulation, theoretically, anything is possible, so it is crucial to have a very clear vision of which style of riding the wing aims to achieve and how it should feel. In the end, it also needs to be producible, ready for production, the shape can’t be too complicated.” Despite all the technical advancements, the interaction of water testing and analysis is still key to bringing the feedback from the test riders into the design process as well. In the end, the foil needs to live up to the expectations of the riders and the customers.  With the help of iXent and their state of the art technology, Duotone ensures to meet the performance goals for every style of foiling: “It enables us to balance from an easy foil to ride all the way to a very playful one” Max Pajank, Product Manager at Duotone, says. “Enhancing stability for our entry- level Spirit Freeride Foil, for example, making the Spirit Carve quicker in turns or creating more lift for the Spirit Surf, with these modern technologies we have access to a huge spectrum of possibilities for adapting a wing. It enables us to change any parameter of the wing, even if it needs just minimal adaption, thus being able to fine-tune the wings in a way that would be unthinkable with physical prototypes”. One of Duotone’s biggest achievements regarding foil development is the steps between different wing sizes feel very smooth and familiar. Due to the layer structure of the wings being modelled to become one “flex-family”, pitch stability (or front foot pressure) feels similar if not the same when using a different size of wing. “The wing might be a little smaller and faster, but the front foot pressure still is the same, from low to top speed. It kind of feels like “the little brother” of the bigger wing. So picking up speed is quite controllable now.” Max tells us. Another advantage is that the mast doesn’t need to be shifted anymore when changing the size of the wing. “You just find one setup that suits you and you keep it, no matter the size of the wing you choose.” With the help of iXent’s modern technologies, Duotone can attack new developments with fast turn arounds. This reflects in the products and lays the groundwork for the realization of more exciting projects to come. *DEFINITION/TECH TALK Hydrodynamics is a branch of physics that deals with the motion of fluids and the forces acting on solid bodies (like a foil) immersed in fluids and motion relative to them. CFD–Computational Fluid Dynamics Simulation– is used by automobile designers, aerospace engineers and sports equipment manufacturers to reduce the drag and friction of air or water while improving the efficiency of their products. FEA/FEM–The Finite Element Method (FEM) is a widely used method for numerically solving differential equations arising in engineering and mathematical modelling. Typical problem areas of interest include the traditional fields of structural analysis, heat transfer, fluid flow, mass transport, and electromagnetic potential. F O I L I N G Deformation plot of the front wing under load 106 D R I V I N G F U T U R E I N N O V A T I O N S Leopold Fricke, Engineer at iXent and former athlete of the German National Team in the Olympic 49er Sailing Class, being two times German Champion Max Pajank, Product Development at Duotone Kiteboarding Stress plot of carbon fibers under load Photo  Craig Kolesky Photo  Kathrin Pitsch 107 D R I V I N G F U T U R E I N N O V A T I O N S