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This is an excerpt from the Fourth Quarter 2013 edition of the Wind Program R&D Newsletter.

The U.S. Department of Energy's National Renewable Energy Laboratory (NREL) recently released an expanded version of its FAST wind turbine computer-aided engineering tool under a new modularization framework. The new framework will transform FAST into a powerful, robust, and flexible modeling software for wind and water power technology developers. The new release includes:

  • An upgraded version of the AeroDyn aerodynamics module that includes tower drag loading
  • The capability to analyze multimember offshore wind turbine substructures
  • A new state-space hydrodynamic theory option in the HydroDyn hydrodynamics module
  • A new Mooring Analysis Program for modeling multisegmented mooring quasi-static behaviors of floating offshore wind turbines
  • Full conversion of FAST into the new modularization framework.

The upgraded version of AeroDyn can simulate both the upwind and downwind influences of the wind turbine tower on the rotor and calculate drag load on the tower.

The multimember offshore wind turbine module enables the software to model the hydrodynamic loading and structural dynamics of multimember, fixed-bottom offshore wind substructures such as tripods and jackets. These types of offshore wind structures are being built in water depths between 30 and 60 meters. The substructures can be composed of multiple interconnecting members with incline, and the members can include the effects of flooding and marine growth.

The new state-space hydrodynamics option in HydroDyn enables more computationally efficient time-domain solutions than the previously available implementation, and permits model linearization that is important for modal analysis, linear system-based controls design, and linearized stability analysis.

The Mooring Analysis Program simulates the quasi-static behavior of complex multisegmented mooring systems—a critical component of both wave energy conversion and floating offshore wind systems.

The new FAST modularization framework improves the ability to read, implement, and maintain source code; increases module sharing and shared code development across the wind community; improves numerical performance and robustness; and enhances flexibility and expandability to enable further developments of functionality without the need to recode established modules. Read more about FAST's new framework.

In November 2013, NREL presented a full-day workshop on FAST in Frankfurt, Germany, hosted by the University of Stuttgart. The workshop was attended by 50 participants, including equipment manufacturers, consultants, certifiers, laboratory researchers, and university professors and graduate students from across Europe and Asia. Workshop topics included basic theory, structure, capabilities, and future plans for FAST; this was the first workshop to focus on FAST in its new modular framework. Workshop materials can be downloaded at the Announcements of Modeling Workshops page.