Initial results of an ongoing Navier-Stokes Computational Fluid Dynamics study of horizontal axis tidal current turbine hydrodynamics are presented. Part of the underlying motivation is assessing the effects of the Reynolds number on turbine performance and loads in steady and unsteady flow regimes. The study aims at a) providing initial verification and validation of Navier-Stokes CFD for stea...

This paper studies the effects of viscous loss, flow separation and base pressure for ducted turbine designs using computational fluid dynamics (CFD) simulation. Analytical model coefficients for inlet and diffuser efficiency and base pressure coefficient parameterize these effects and have been identified from CFD results. General trends are: the inlet efficiency is nearly unity for the simula...

Liquid Natural Gas (LNG) processing facilities typically are located on ocean shores for easy transport of LNG by marine vessels. These plants use large quantities of water for various process streams. The combined wastewater effluents from the LNG plants are discharged to the coastal and marine environments typically through submarine outfalls. Proper disposal of effluents from an LNG plant is...

We developed a new wind turbine system that consists of diffuser shroud with broad-ring brim at the exit periphery and inside it. The shrouded brimmed diffuser, which we called “wind lens turbine” (WLT), has demonstrated power augmentation by factor about 2–5 compared bare for given diameter speed. increase in output depends on shape length height. However, simple theory presented this paper ar...

With many Tidal Energy Conversion (TEC) devices at full scale prototype stage there are two distinct design groups for Horizontal Axis Tidal Turbines (HATTs). Devices with a yaw mechanism allowing the turbine to always face into the flow, and devices with blades that can rotate through 180 to harness a strongly bi-directional flow. As marine turbine technology verges on the realm of economic vi...

It is now widely accepted that a shift towards renewable energy production is needed in order to avoid further anthropogenically induced climate change. The ocean provides a largely untapped source of renewable energy. As a result, harvesting electrical power from the wind and tides has sparked immense government and commercial interest but with relatively little detailed understanding of the p...

Harnessing the remaining energy downstream of dams has recently gained significant attention as kinetic available in water current is considerable. This work developed a novel study to quantify gain using horizontal-axis hydrokinetic turbine with diffuser. The present assessment uses field data from Tucuruí Dam, where stream velocity 2.35 m/s at which highest extraction can occur. In this case,...

It is important to understand tidal stream turbine performance and flow field, if tidal energy is to advance. The operating condition of a tidal stream turbine with a supporting structure has a significant impact on its performance and wake recovery. The aim of this work is to provide an understanding of turbine submerged depth that governs the downstream wake structure and its recovery to the ...