The Effects of Surface Debris Diversion Devices on River Hydrodynamic Conditions and Implications for In-Stream Hydrokinetic Development

• Main Author: Horacio Toniolo
• Format: Article
• Language: English
• Published: MDPI AG 2014-07-01
• Series: Water
• Subjects: surface woody debris; debris diversion devices; vorticity; hydrokinetics; river hydrodynamics; macro-turbulence
• Online Access: http://www.mdpi.com/2073-4441/6/8/2164

Floating objects designed to divert woody debris—known as debris diversion devices—can protect hydrokinetic turbines deployed in rivers; they also change the hydrodynamic conditions of a river, at least locally. Modifications associated with velocity adjustments in both magnitude and direction would be expected. Thus, one could assume that extra macro-turbulent levels would be found immediately behind a device and downstream of that location. This article presents a set of cross-sectional and longitudinal velocity measurements carried out to quantify these effects. Results show important changes in the velocity components. In addition, significant changes in the vorticity field, calculated along cross-sectional profiles, demonstrate the role of a submerged chain used to maintain the debris diversion device in place. More importantly, findings suggest that hydrokinetic turbines should not be installed in a river’s central area behind a debris diversion device, due to the additional turbulence created by the submerged chain.