Craig Hill Receives PhD for dissertation titled "Interactions Between Channel Topography and Hydrokinetic Turbines: Sediment Transport, Turbine Performance, and Wake Characteristics"

PhD candidate Craig Hill successfully defended his dissertation in Civil, Environmental, and Geo-Engineering on Friday, August 14th in the SAFL auditorium. Craig's advisors are Dr. Michele Guala and Dr. Fotis Sotiropoulos, both associated with the St. Anthony Falls Laboratory and Department of Civil, Environmental, and Geo-Engineering at the University of Minnesota. Congratulations, Dr. Hill!

Interactions Between Channel Topography and Hydrokinetic Turbines: Sediment Transport, Turbine Performance, and Wake Characteristics

Accelerating marine hydrokinetic (MHK) renewable energy development towards commercial viability requires investigating interactions between the engineered environment and its surrounding physical and biological environments. Complex energetic hydrodynamic and morphodynamic environments desired for installing MHK devices present difficulties for designing efficient yet robust sustainable devices, while permitting agency uncertainties regarding device environmental interactions result in lengthy and costly processes prior to installing and demonstrating emerging technologies. A research program at St. Anthony Falls Laboratory (SAFL), University of Minnesota, utilized multi-scale physical experiments to study the interactions between axial-flow hydrokinetic turbines, turbulent open channel flow, sediment transport, turbulent turbine wakes, and complex hydro-morphodynamic processes in channels. Model axial-flow turbines (rotor diameters, d_T = 0.15m and 0.5m) were installed in open channel flumes with both erodible and non-erodible substrates. In erodible channels, device-induced local scour was monitored over several hydraulic conditions (clear water vs. live bedload transport) and material sizes. Synchronous velocity, bed elevation and turbine performance measurements provide an indication into the effect channel topography has on device performance. Experiments were also performed in a realistic meandering outdoor research channel with active sediment transport to investigate MHK device interactions with bedform migration and turbulent flow in asymmetric channels, providing new insight into turbine-sediment interactions and turbine wake behavior in curving channels. The suite of experiments undertaken during this research program at SAFL provides an in-depth investigation into how axial-flow hydrokinetic devices respond to turbulent flow and topographic complexity, and how they impact local and far-field sediment transport characteristics. Results provide the foundation for investigating advanced turbine control strategies for optimal power production in non-stationary environments, while also providing robust data for computational model validation enabling further investigations into the interactions between energy conversion devices and the physical environment.