Large-eddy simulation has been used to model the atmospheric boundary layer flowing through a span-wise periodic array of wind turbines. The wind turbines are modelled using a coupled simulation in which the FAST wind turbine simulation code from NREL operates within a CFD environment. The wind turbines are implemented in the flow-field using the actuator sector technique, and operate dynamical...

The technical approach in this project involves three types of models: (1) the two-scale electromagnetic scattering model, which relates the radar backscatter to the surface wave spectrum, (2) the wave action model, which describes the relationship between the surface wave spectrum and the near-surface wind field, and (3) atmospheric dynamical models that describe or constrain the spatial varia...

Passive acoustic detection is being increasingly used to monitor visually cryptic cetaceans such as Blainville's beaked whales (Mesoplodon densirostris) that may be especially sensitive to underwater sound. The efficacy of passive acoustic detection is traditionally characterized by the probability of detecting the animal's sound emissions as a function of signal-to-noise ratio. The probability...

Dual-Doppler lidar is a powerful remote sensing technique that can accurately measure horizontal wind speeds and enable the reconstruction of two-dimensional wind fields based on measurements from two separate lidars. Previous research has provided a framework of dual-Doppler algorithms for processing both radar and lidar measurements, but their application to wake measurements has not been add...

Several recent works [such as Vachon et al. 1996, Scoon et al. 1996 and Korsbakken et al. 1997] report promising results when wind retrieval models developed for the wind scatterometer (WSC) are applied to SAR data. The general conclusion from these works is that more validation is needed since the available in-situ material is relatively limited. A dataset from the ERS-1/2 Tandem phase allows ...

[1] The scatterometer ocean wind retrieval process produces several possible solutions or ambiguities at each point, requiring a separate ambiguity selection step to infer a unique wind vector field. An ambiguity selection error occurs when the selected wind vector is not the closest ambiguity to the true wind. The current ambiguity selection routine for SeaWinds is ad hoc, but performs well un...

The Earth’s population is facing an increasing demand for electrical power. After the recent Kyoto meeting, which gave clear signals of reductions in the CO2 emission to the atmosphere, it is clear that new alternative sources of power must be considered to meet these needs. In this context, the possibilities for increasing the utilisation of converting wind energy into electrical power by use ...

An experimental study is conducted to characterize the dynamic wind loads and evolution of the turbulent vortex and flow structures in the wake of a horizontal axis wind turbine (HAWT). In addition to measuring dynamic wind loads (both aerodynamic forces and moments) acting on a wind turbine model, a high-resolution Particle Image Velocimetry (PIV) system was used to make “free-run” and phase-l...

The cross-polar potential drop 8pc and the lowlatitude asymmetric geomagnetic disturbance field, as indicated by the mid-latitude ASY-H magnetic index, are used to study the average magnetospheric response to the solar wind forcing for southward interplanetary magnetic field conditions. The state of the solar wind is monitored by the ACE spacecraft and the ionospheric convection is measured by ...

Fossil Fuels are always considered as environmental pollutants. On the other hand, the political and economic situations highly affect the price of these fuels. Offshore wind and wave, as renewable energy sources, represent the better alternatives for electricity generation. Therefore, it is necessary that wind speeds effectively be estimated due to the absence of field measurements of the wind...