Tidal energy is the most foreseeable form of renewable energy. Tidal energy can be harnessed by tidal barrage, tidal fence and tidal current technologies. Present efforts are focused on diffuser augmented tidal turbines that exploit the kinetic energy of the tidal currents. The power output by a tidal turbine is directly proportional to the cube of velocity of incoming fluid flow. Thus, even a ...

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...

A new class of diffuser augmented wind turbines (DAWTs) is presented. The new diffuser concept exploits aero-dynamic principles for the creation of high-lift airfoil configurations known from the aircraft industry. Combining this with our objective of obtaining a compact power-efficient design has enabled creation of a family of DAWT designs with energy capture potentials which exceed the power...

The wind turbine power decreases at low speed. A flanged diffuser plays a role of device for collecting and accelerating the approaching wind, thus optimization shape presents an important way to enhance power. In this work, numerical parametric study was conducted on obtain initial optimum form diffuser. Then, Simplex algorithm is used optimal starting from obtained shape. Finally, with conven...

We have developed a new wind turbine system that consists of a diffuser shroud with a broad-ring brim at the exit periphery and a wind turbine inside it. The shrouded wind turbine with a brimmed diffuser has demonstrated power augmentation by a factor of about 2–5 compared with a bare wind turbine, for a given turbine diameter and wind speed. This is because a low-pressure region, due to a stro...

The Diffuser Augmented Wind Turbines (DAWTs) have been widely studied, since the diffusers improve the power coefficient of the wind turbine, particularly of small systems. The diffuser is a device which has the function of causing an increase on the flow velocity through the wind rotor plane due to pressure drop downstream, therefore resulting in an increase of the rotor power coefficient. Thi...

An implication of a turbine current is the development wake, reduced speed flow, thus affecting performance an adjoined turbine. The aim this study to examine wake properties offer basic framework for exploration efficient arrangements through OpenFOAM source package and entropy production theory. results indicate that diffuser inlet produces largest rate; however, dissipates quickly after roto...