This paper presents a recent numerical study conducted by researchers at the National Renewable Energy Laboratory on a point absorber wave energy conversion (WEC) system using a Reynolds-averaged Navier–Stokes (RANS)-based Computational Fluid Dynamics (CFD) method. The device we studied was a two-body floating-point absorber (FPA) that operates predominantly in heave and generates energy from t...

Laser-induced bubbles can be caused by an optical breakdown in water. They are a result of the optodynamical process where the energy of a high intensity laser pulse is converted into the mechanical energy through an optodynamic conversion. At this process the absorbed optical energy causes plasma expansion that in turn initiates dynamic phenomena: spreading of a shock wave and the development ...

The ISWEC (inertial sea wave energy converter) is presented, its control problems are stated, and an optimal control strategy is introduced. As the aim of the device is energy conversion, the mean absorbed power by ISWEC is calculated for a plane 2D irregular sea state. The response of the WEC (wave energy converter) is driven by the sea-surface elevation, which is modeled by a stationary and h...

The conversion of Ocean Renewable Energy (ORE) sources to electricity could meet increasing energy demand and diversify the supply in Malaysia. Possessing a long coastline overlooking South China Sea (SCS) Malacca strait has encouraged Malaysian government promote ORE assess available resources reduce its dependence on fossil fuels. However, most previous attempts potential have focused primari...

The Double Decker Turbine (DDT) is a recent design introduced for oscillating water column (OWC) devices. Its major contribution the combination of two typical solutions in just one prototype: self-rectifying performance, to deal with bidirectional flow, and twin-turbine concept, allowing use unidirectional turbines. This achieved by set concentric turbines, called external internal turbines (E...

We report on a particularly strong third-order nonlinear response from nanostructured gold surfaces. Two incident laser beams with frequencies omega{1} and omega{2} give rise to four-wave mixing (4WM) fields with frequencies 2omega{1}-omega{2} and 2omega{2}-omega{1}. We demonstrate that the nonlinear response can be purely evanescent and that nanostructured surfaces convert the evanescent energ...

We report experimental results demonstrating 54% power conversion efficiency ~43% energy conversion efficiency!, from a two-stage X-band traveling wave tube amplifier designed for high-power operation. The first stage of the amplifier is a 12-cm-long Boron Nitride dielectric section used to modulate the electron beam. The second stage consists of a long high-phase-velocity bunching section foll...

Semiconductor-based photocatalytic, photoelectrochemical, and photovoltaic solar-energy conversion has been considered very promising to address the energy and environmental challenges. At the heart of the technology is the lack of suitable semiconductor materials and efficient systems that can perform the solar-energy conversion efficiently and inexpensively. Much work needs to be done in this...