Alfredo Pena Diaz

Length Scales of the Neutral Wind Profile over Homogeneous Terrain

Abstract The wind speed profile for the neutral boundary layer is derived for a number of mixing-length parameterizations, which account for the height of the boundary layer. The wind speed profiles show good agreement with the reanalysis of the Leipzig wind profile (950 m high) and with combined cup–sonic anemometer and lidar measurements (300 m high) performed over flat and homogeneous terrain at Hovsore, Denmark. In the surface layer, the mixing-length parameterizations agree well with the traditional surface-layer theory, but the wind speed profile is underestimated when the surface-layer scaling is extended to the entire boundary layer, demonstrating the importance of the boundary layer height as a scaling parameter. The turbulence measurements, performed up to 160-m height only at the Hovsore site, provide the opportunity to derive the spectral-length scales from two spectral models. Good agreement is found between the behaviors of the mixing- and spectral-length scales.

Inflow characterization using measurements from the SpinnerLidar: the ScanFlow experiment

We present a preliminary analysis of inflow measurements performed with a SpinnerLidar on a turbine’s nacelle and those from three grounded-based short-range continuouswave lidars (WindScanners) during the ScanFlow experiment. After proper filtering for blade contamination and hub/nacelle shading of the beam, the SpinnerLidar measurements capture the structure of the inflow in detail. The WindScanners’ 3D measurements provide estimations of the three wind speed components without any flow assumptions. These 3D wind field measurements are used as reference to evaluate SpinnerLidar reconstructed winds. A wind reconstruction methodology for the SpinnerLidar measurements is evaluated against a numerical wind inflow simulation successfully. An intercomparison between reconstructed longitudinal velocity components from the WindScanners and the Spinnerlidar shows good agreement (no bias and high correlation) at hub height and close to zero biases for all vertical levels measured by the SpinnerLidar.