Abstract A nacelle‐mounted lidar system pointing downstream has been used to measure wind turbine wake dynamics. The new measurement and data analysis techniques allow estimation of quasi‐instantaneous fields in planes perpendicular the rotor axis. newly developed tracking procedure delivers instantaneous transversal position which is quantitatively compared with prediction Dynamic Wake Meandering model. results, shown for two 10‐min time series, suggest that conjecture behaving as a passive...

Abstract. As part of the ongoing X-Wakes research project, a 5-month wake-measurement campaign was conducted using scanning lidar installed amongst cluster offshore wind farms in German Bight. The main objectives this study are (1) to demonstrate performance such system and thus quantify wake effects reliably (2) obtain experimental data validate effect simulated by flow models involved project. Due lack free for directions, speeds obtained from mesoscale model (without any farm...

Taylor’s frozen turbulence hypothesis is tested in its applicability for wind turbine applications. In this research full field measurements are performed at a test site multi-megawatt turbines by means of pulsed LIDAR with scanning device. The system installed the top nacelle 5MW turbine. It provides simultaneous speed, maximum sampling rate 5 Hz, different stations parallel to mean wind. Measurements range between 0.4 and 1.6 rotor diameter following several two three dimensional...

Large-Eddy Simulations (LES) are more and used for simulating wind turbine wakes as they resolve the atmospheric well wake turbulence. Considering expenses sparsity of offshore measurements, LES can provide valuable insights into flow field in farms. However, an application fields to assess farm flow, a proper validation with measured data is necessary. Such requires that closely reproduce conditions during measurement. For this purpose, representation large-scale features drive required....

Abstract. Presently there is a lack of data revealing the behaviour path followed by near wake full scale wind turbines and its dependence on yaw misalignment. Here we present an experimental analysis horizontal deviation 5 MW offshore turbine between 0.6 1.4 diameters downstream. The field has been scanned with short-range lidar reconstructed means two-dimensional Gaussian tracking. We analysed measurements for rotor misalignments arising in normal operation during partial load,...

Commonly, wake models are calibrated in wind tunnels or using flow simulations with a wide degree of physical details. In general, it is assumed that these methods cannot fully reproduce the real operating conditions turbines. This research aims at investigating calibration an analytical single model relation to full-scale measurements. Within this scope, we fitted measurements realised lidar installed on nacelle offshore turbine. We studied parameters returned by fit separating cases...

Remote sensing techniques like LiDAR offer many novel applications to the wind energy community, e.g. fast and accurate measurements of inflow wake fields from turbine nacelle. The prospects such a new technique are evaluated with software tool simulating nacelle-based system. paper presents implementation application simulator that has been conceived support design field scanning procedures. helps optimize hardware setup, trajectories frequency. Furthermore it can be coupled an aeroelastic...

Newly designed multicomponent light alloys are giving rise to non-conventional microstructures that need be thoroughly studied before determining their potential applications. In this study, the novel Al58Zn28Si8Mg6 alloy, previously with CALPHAD methods, was cast and heat-treated under several conditions. An analysis of phase evolution carried out in situ X-ray diffraction supported by differential scanning calorimetry electron microscopy. A total eight phases were identified alloy...

The wind energy community is in need of detailed full-field measurements the wake turbines. Here, three dimensional(3D) vector field obtained near-wake region behind a full-scale test turbine are presented. Specifically, NEG Nordtank turbine, installed at Risoe field, has been measured from 0 to 2 diameters downstream. For this, ground-based synchronised short-range WindScanners and spinner lidar have used. 3D velocity reconstructed horizontal vertical planes crossing hub. 10-min mean values...

Wind measurements of a 2D Multi-Lidar and mast mounted cup anemometer are compared in this study. Average wind speed direction as well the turbulence intensity considered. Data analysis is mainly performed using standard regression on 10 minute average data calculation power spectral density. The results show good agreement regarding horizontal wind.

Abstract. Presently there is a lack of data revealing the behaviour path followed by near wake full scale wind turbines and its dependence on yaw misalignment. Here we present an experimental analysis horizontal deviation 5 MW offshore turbine between 0.6 1.4 diameters downstream. The field has been scanned with short range lidar reconstructed means two-dimensional Gaussian tracking. We analysed measurements for rotor misalignments arising in normal operation during partial load,...

Abstract. To establish long-term flow measurements for the validation of wake models, a scanning Doppler wind lidar system was installed at western edge farm Gode Wind 1 in German Bight period five months. The main goal to detect wakes from clusters different directions and atmospheric stabilities. data are categorized into sectors based on upstream conditions. influence stability initially investigated with respect airborne collected within measurement period. Mesoscale simulations used as...

In spite of the efforts made at time installation wind vanes or ultrasonic anemometers (Sonic), there is always a remaining uncertainty several degrees in absolute north such sensors. this research method presented to reduce azimuthal orientation error direction sensors by means Doppler Lidar measurements. The based on comparison between conventional sensor and distant long range lidar pointing it staring mode. By comparing their line-of-sight speeds any misalignment both systems can be...

New LiDAR techniques are being tested and developed to support the development of large offshore wind turbines. Our interest in this paper is concentrated wake measurements; therefore, a pulsed standard adapted for fullscale field measurements from nacelle turbine. We show conceptual framework planned adaptations Windcube® operation at 5 MW The scanning mode be modified properly obtain downstream also upstream speeds. intended verification models near-wake speed, meandering new predictive...

The validation of dynamic wake meandering models by full field measurements is an important but challenging task. Recently a new approach has been proposed, where long range lidar was employed to analyse the power spectral density line sight wind component measured across trajectory. method promising, number useful time series within measurement campaign depends large extent on favourable geometrical setup position and direction. In first part paper further investigated. To this avail,...

The vast majority of wind turbines are today erected in farms. As a consequence, wake generated loads becoming more and important. We present new successful experimental technique, based on remote sensing, to measure instantaneously the flow turbines. Downstream speed can be quantified spatially one two dimensions. Data analysis allows us identify transversal position, thus enabling quantify meandering as well instantaneous expansion expressed frame reference. results subsequently used...