Numerical study of ducted turbines in bi-directional tidal flows

Developments in ducted water current turbines

Unlike conventional hydro and tidal barrage installations, water current turbines in open flow can generate power from flowing water with almost zero environmental impact, over a much wider range of sites than those available for conventional tidal power generation. Recent developments in current turbine design are reviewed and some potential advantages of ducted or “diffuser-augmented” current...

Potential Flow Calculations of Axisymmetric Ducted Wind Turbines

An incompressible potential-flow vortex method has been constructed to analyze the flow field of a ducted wind turbine following that outlined by Lewis (1991). Attention is paid to balancing the momentum change in the flow to the total longitudinal forces acting on the duct-turbine combination: the pressure force on the actuator disk plus the pressure forces acting on the duct, which typically ...

Unsteady Flows in Turbines

Ducted Turbine Blade Optimization Using Numerical Simulation

This paper presents a combined blade element (BE), computational fluid dynamics (CFD) method for performance analysis and optimization of ducted turbines. The model is similar to standard blade element momentum theory, except that CFD replaces the momentum equation for determining the induction factors. This eliminates many assumptions used in applying the typical blade element momentum (BEM) t...

Flow Misalignment and Tidal Stream Turbines

Extensive Research and Development (R&D) within the tidal energy industry is pushing this sector towards commercial viability, with full scale prototypes starting to meet the challenges of the marine environment. This paper combines velocity data collected from Ramsey Sound (Pembrokeshire, Wales), with Computational Fluid Dynamics (CFD) to assess the impact of non-rectilinear flows on turbine r...