Abstract
A dual-rotor axial-flow hydrokinetic turbine has been developed to harness the potential in river current energy. The river turbine design aims to complement existing renewable energy sectors such as wind and solar energy, to provide additional energy production. With a focus on sustainability and environmental preservation, the device offers an inconspicuous solution to contribute to baseload energy production in both urban and remote areas. The device is compact measuring 2.4m in width, 3m in length, and 1m in height, intended for array installation, and adaptable to various river sizes with relevant potential. A prototype deployed in Munich, Germany rests within a canal that stretches 5m wide and 3m in depth. Here the 0.8m diameter rotors operate at a flow velocity of 1m/s in waters heavily saturated with debris, demonstrating consistent energy production at approximately 500W per deployed unit, amounting to potentially 4.38MWh per year. Although these metrics are noteworthy, continuous development and optimization of the technology is required to further maximize energy extraction. An ongoing collaboration between the University of Minnesota – Duluth and Energyminer GmbH explores the relationship between key design features and power production of the turbine, focusing primarily on the turbine’s diffuser geometry. Further emphasis is placed on investigating these effects at low flow velocities, as optimization in this region will allow for the deployment in a larger variety of flow conditions. Previous numerical and experimental studies conducted by Energyminer have identified outlet-inlet area ratio among other design parameters influencing turbine efficiency. An ongoing study uses 2D Ansys Fluent CFD simulations to parameterize these geometric design variables to explore velocity and pressure field variations and their potential impact on turbine thrust loads. As design parameters have a large influence on overall mass and volume of the turbine, these findings will guide manufacturing decisions as the company moves towards full scale production. Discussion will highlight design parameterization, flow field variations, and additional ongoing collaborative efforts to advance Energyminer’s river turbine technology.