This project will study tethered, undersea kite (TUSK) systems; a new hydrokinetic energy technology. In a TUSK system, a tethered, rigid-winged hydro-kite is submerged in an ocean or tidal current and controlled to move in high-speed cross-current motions. A turbine is mounted on the hydro-kite in one TUSK concept, or the flexible unwinding tether transmits generated hydrodynamic forces to a power generation system in another concept. TUSK systems have potential advantages over conventional marine turbines, mainly that TUSK systems will be able to generate cost-effective energy with; 1) smaller, less costly systems, and 2) at more locations within ocean currents and tidal flows where current speeds are too low to make marine turbines feasible. The main benefits are: 1) the hydro-kite can move in high-speed cross-current motions (much like a kite in air) over large swept areas to greatly increase power output, 2) TUSK systems eliminate the need for large diameter turbines and costly support structures, 3) TUSK systems are easier to maintain, and 4) TUSK systems are scalable.
The main goal of the proposed work is to identify and select an optimum TUSK concept and then demonstrate feasibility through modeling, numerical simulation and sub-scale experimental work. A fundamental knowledge base for design of stable, scalable, durable, and cost-efficient tethered undersea kites will be obtained. This knowledge will serve as the basis for further scaling and development of the technology to full-scale systems.
This project will lay the foundation for understanding how such systems behave by integrating analytical models and robust control solutions, numerical simulations with sufficient accuracy suitable for system design, and physical experiments on TUSK system components where we partner with a local hydrodynamics research lab. The proposed work will advance knowledge in hydrodynamics of underwater vehicles, novel control system applications, and numerical simulation of complex systems. The project will examine tracking controllers to yield optimal periodic trajectories in the presence of modeling errors and disturbances. The proposed numerical simulations will constitute the first CFD work on tethered undersea kite systems, fully accounting for hydrodynamic forces, support platform motions, and the flexibility and influence of the tethers. The integrated work will allow the PIs to examine the behavior and robustness of the system under different conditions and control solutions to improve the design of TUSK systems.
This research project will set the stage for the further study and eventual full-scale deployment of this new energy conversion technology by the systems and control, CFD, and hydrokinetic energy communities as well as commercial enterprises, through dissemination of the results at conferences and in archival journals. The research will be strongly integrated with undergraduate and K12 education through undergraduate.