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INEOS TEAM UK is a commercial sporting team led by four-time Olympic gold medal-ist and 34th America’s Cup winner, Sir Ben Ainslie. The team’s long-term aim is to bring the prestigious America’s Cup back to Britain, where the first challenge was held in 1851 off the Isle of Wight.
Class rules for the 36th America’s Cup of 2021, announced at the end of March 2018, introduced a dramatic change in design. As Grant Simmer, chief executive of INEOS TEAM UK, observed: “This time around, boat designs are very large, powerful and complex with a completely new type of configuration.” As a result, the team’s first boat, launched in October 2019, is a foiling monohull that is over 20 meters long, weighs 7,800 kg and is made of 25,000 unique parts. The stock, fairing, wing, flaps and systems in each foil arm weigh 1,385 kg.
The technical challenge is extended by another new rule. Nick Holroyd, chief designer, explains: “Teams have got used to being able to change parts such as the foils and reconfigure boats according to the weather on race day. For the next America’s Cup, we have a fixed configuration, which we are required to declare five days in advance. As racing is expected to last for ten days that means that we need to go for a rather general design which will sail well with any wind speed, both on the straight and going around corners.”
A foil optimized for low speed in light wind is very different from one designed to withstand strong winds and high speed, so the team had to work around average wind speeds in Auckland, where the next race takes place in March 2021. The team weighted types of weather according to their likelihood at that time of year, then scoped a design around those parameters.
From receiving the class rules in April 2018, the team spent five intense months focusing solely on design, with construction beginning in August that year. It took 90,000 design hours and 50,000 construction hours to get the boat on the water. “We designed from scratch but we could draw on all the simulation tools and expertise that we already had in place,” comments Holroyd. Those tools include NX™, Teamcenter® and Simcenter™ software from Siemens Digital Industries Software.
“We relied on our simulation environment whilst the first boat was being built,” Holroyd continues. “One of the first requirements after the launch was there-fore physical testing to validate what our simulation showed. We expect all our simulation to be within a two percent margin; even so, there’s always a surprise and one of the fun aspects of the job is to turn such nuggets of information into an opportunity for our design.”
Under race rules the team is limited to developing two boats with a maximum of three rigs, four rudders and three pairs of wings, so again the team needs to rely on simulation. “Because we cannot develop spares, the fidelity of our computational solutions is paramount,” comments Holroyd.
“A racing yacht sits at the interface between two fluids, wind and water, deriving all its power from that dynamic by minimizing drag,” says Holroyd. “However, we can’t work with that in isolation. We have to consider structural and mechanical features, and for the boat to ‘fly’ we need to get the foils up to speed very quickly; but at high wind we quickly run into cavitation, when pressure reduces too much over the foil.”
INEOS TEAM UK relies on Simcenter™ STAR-CCM+™ software for computational fluid dynamics (CFD) to model the lift forces acting on the foil. Modeling shows how the flow is developing, changing, for example, from laminar to turbulent, and how it might separate, creating a drop in pressure and creating cavitation or a “boil-ing” effect in the water.
CFD engineer Max Starr spends 90 percent of his day using Simcenter STAR-CCM+. “When we receive a CAD file the geometry is pretty complex and often not the clean-est. We need to throw some mesh on before we can solve. We can very quickly facilitate meshing issues without having to fix the geometry manually and that means we achieve a very low failure rate.” According to Starr, the team tends to run hundreds of short, one-hour simulations in parallel. “We gain much more from these than from one long simulation that takes weeks,” he explains. “Simcenter STAR-CCM+ has a Design Manager feature which is very smart and handles changes really easily. Design Manager will manage all the parameters and present results as a table.”
“We have established extensive automation within NX,” comments Ollie Pendleton, design engineer with responsibility for managing the Siemens solution. “We have a lot of parameterized models on which we can change fundamental aspects and let NX update. This allows for speedy last-minute changes and is particularly helpful as deadlines mount and we start to see other boats. We can quickly adjust our own models in order to understand the approach adopted by other teams.”
The design team also takes advantage of the automation and high-level scripting which it has built into Simcenter STAR-CCM+. As a result, non-CFD specialists can design a foil and define the matrix and test conditions.
Another rule is that teams are not allowed to test in any closed environment such as a wind tunnel, so the pressure is back on simulation. “The challenge is to work out the combined forces acting on the boat and calculate the loads on the foils, the hull and the crew,” Holroyd says. “The calculations we gain from our software solution form the basis for waves and gusts introduced to a motion platform on which the sailors train, complete with virtual reality headsets and graphics.
The sailing team, which began using this simulator in 2018, are in continual dialog with the design team regarding the feel and behavior of the boat. Starr adds “We can gather feedback from over 100 differ-ent points on the boat to work out the pitch, roll and yaw then convert that data into a sensitivity reading, positive or negative, for each of the components.”
“Teamcenter is essential for collaboration because everyone needs to see the absolute latest data,” states Pendleton. “Teamcenter stores all assemblies and takes care of the release of models and drawings to suppliers. Within the Siemens suite we can integrate design and analysis with hydraulic and electrical schematics. That is very valuable to us as the design gradually evolves into digital manufacturing and the issue of files to suppliers.
There’s always pressure, especially as there might be 25,000 parts out for procurement, but the support we receive from Siemens is very hands-on. Our dedicated support engineers really understand our needs and our coding.”
The team’s second and final boat hits the water in the summer of 2020 and in early 2021 sailing begins in earnest. “The rules and regulations push our research and development further into the digital world and our success depends on what decisions we made at the start regarding our broad technical strategy and where to concentrate effort,” comments Simmer. “To be competitive we are constantly balancing associated risk with performance reward and the resources that we can apply. Our use of the Siemens solution is fundamental to how we do that."