System Design and Operation: Riverine Turbine Testing and Mooring Design

Project Lead: William Baxley, MS, PE
Affiliated Home Campus: Harbor Branch
Affiliated Department: Southeast National Marine Renewable Energy Center
REU Scholar: Brynn Bartholomew & Eric Schaefer
REU Scholar Home Institution: Auburn University & Florida Atlantic University

PROJECT

Traditionally, energy has been harnessed from rivers through the construction of dams and hydroelectric power plants. However, rivers also offer clean, usable, and reliable hydrokinetic power that can be captured by river current turbine systems. Communities located along rivers could significantly benefit from the development of river current turbine technology for small-scale power production, especially in rural communities that rely on power production from diesel generators or similar devices.

One objective of this project was to develop a mooring system capable of suspending a turbine within a river. An ideal mooring system should keep the turbine at an appropriate depth throughout various current speeds, provide continuous and maximized power output, and transport power to land. The system should be durable, cost-effective, and safe while allowing for easy installation and maintenance. Additionally, the system should mitigate damage from debris impact while having minimal impact on local ecosystems. Numerous mooring system designs were explored and simulated using OrcaFlex. Three designs and a hybrid design were selected for further consideration, with each design consisting of two support poles mounted on either side of a river with mooring line(s) connecting the turbine to the support poles in various configurations. The first design was chosen for simplicity and cost-effectiveness, the second design was considered ideal for controlling turbine depth and minimizing contact with debris, and the third design was considered ideal for reducing stresses on the support poles and lines. The hybrid design combined the second and third designs for overall optimal performance.

An additional objective of this project was to improve methods of testing turbines and their components prior to employment. A previous REU project focused on creating a turbine blade testing device equipped with strain gauges to measure the forces on a turbine blade at various flow speeds and angles of attack. This device is intended to be mounted on a vessel that can mimic flow patterns by traveling through a current in different directions. For this project, MATLAB code was developed to gather, analyze, store, and display data as it is collected from the strain gauges and a GPS system onboard the vessel to streamline turbine testing.

Future research should focus on further optimization of the turbine testing software, redesign of the testing device, and refinement of the mooring system designs.

Click here to watch the student presentation.