Experimental and numerical characterization of a full-scale portable hydrokinetic turbine prototype for river applications

A preliminary hydrokinetic turbine prototype for river applications was built for experimental testing at the circulating water channel at the Naval Surface Warfare Center, Carderock Division. The prototype was designed based on numerous blade characterization and optimization analyses conducted using computational fluid dynamics (CFD) simulations. Testing was conducted for channel flow speeds ranging from 1.0 m/s to 1.7 m/s. At each tested flow speed, the generator loading was manually adjusted to produce a performance curve based off the power output from the prototype unit. In addition to manual generator loading, a solar charging unit was used to simulate turbine operation while adjoined to the ground renewable energy system (GREENS). CFD predictions were produced for the prototype using the k-ω SST turbulence model for the purpose of validation. A peak power coefficient of 0.37 was measured at a tip speed ratio of 2.50 during manual generator loading. Relative error between numerical predictions and experimental results was less than 3.0% when generator, transmission, gearbox, and other losses of selected components were applied to the numerical predictions. The solar charging converter improved prototype operation by conditioning the power output, indicating that the prototype could successfully be integrated with GREENS for portable applications.