AMHERST, Mass. – A team of researchers at the University of Massachusetts Amherst headed by Blair Perot, professor of mechanical and industrial engineering, is developing new open source computer software for the combined simulation and control co-design of floating offshore wind turbines using a two-year, $1.175 million grant from the U.S. Department of Energy (DOE).
The UMass Amherst project is one of 13 recently announced by the DOE’s Advanced Research Projects Agency – Energy (ARPA-E) as part of a $26 million series called the Aerodynamic Turbines, Lighter and Afloat, with Nautical Technologies and Integrated Servo-control (ATLANTIS) program. These teams will develop new technologies for floating, offshore wind turbines (FOWTs).
The new software being developed by Perot and his team will use an existing free, extensible, and widely supported animation software called Blender to replace the current computer aided design (CAD) software that is typically used for such design work. CAD software is difficult to use, has a steep learning curve, is expensive, and has a framework geared towards static views and design, not the complex, real-world dynamics of offshore wind turbines, the researchers say.
Blender has a fully developed, intuitive graphical user interface that boasts a large pre-existing software user base in the movie and animation community. Blender was originally designed for the computationally demanding task of computer-generated imagery and 3D computer animation for films. (Movie clip made with Blender)
Blender will serve as the user interface for this new co-simulation physics engine. The free Sandia software, Dakota, will then be used through Blender to perform design optimization using a control co-design approach. The Blender animation software “represents objects and the user experience in a way which is intuitive to dynamics and control simulations. This will vastly improve the user experience for the proposed software compared to traditional simulation approaches. The learning curve is much easier for Blender than it is for any CAD software.”
The researchers say that “a floating off-shore wind turbine is a case study in coupled dynamics. Wave action can pitch and heave the platform. Aerodynamic drag and rotational inertia can pitch and yaw the platform. The solid structures can vary widely in their flexibility from the fairly stiff tower, to the partially flexible blades and trailing wing, to the very flexible foam pontoons.”
FOWTs are excellent candidates for control co-design optimization, because they contain significant dynamic characteristics and include the interaction of mechanical, electrical, aerodynamics and hydrodynamics subsystems.
Control co-design brings together various technical disciplines to work concurrently from the start. This methodology enables a more optimal design—with better system dynamics and controllability, among other advantages – that often results in lower system cost and improved reliability.
The research team also says, “Common offshore wind design components such as blades, towers, and platforms (e.g. spar buoys) will be readily accessible from a component library. Each component geometry is easily tailored within Blender. The modular nature of the software will allow additional computational modules besides simulation physics to be added.”
Accessible offshore wind is estimated at more than 25 quadrillion BTU’s per year, with more than half of that generation blowing across water too deep to be economically accessible with current offshore wind turbine design. The FOWT designs in these ATLANTIS projects could enable access to those unutilized wind resources, enabling greater production and market share access in offshore wind energy, according to the DOE.