As a wind turbine extracts energy from the wind, induced wind velocities, lower than the freestream velocity, will be present both upstream and downstream of the rotor. In this study, the upstream induction zone of a 225 kW horizontal axis Vestas V27 wind turbine located at the Danish Technical University’s Risø campus is investigated using a scanning Light Detection and Ranging (lidar) system....

Wind tunnel experiments have been carried out on a small-scale physical model of a municipal waste landfill (MWL) in the CRIACIV (Research Centre of Building Aerodynamics and Wind Engineering) “environmental” wind tunnel in Prato (Italy). The MWL model simulates a landfill whose surface is higher than the surrounding surface, applying a 1:200 scaling factor. Modelling an area source such as lan...

Retrieval of wind fields from a single-Doppler lidar with small azimuthal sectors is challenging. Both simpler retrieval algorithms such as Velocity Azimuth Display (VAD) or Volume Velocity Processing (VVP), and more sophisticated techniques such as Four Dimensional Variational Analysis (4DVAR) using VAD for mean velocities have limitations on small sectors of data. Narrow datasets may result i...

According to the shortcomings of the existing ultrasonic wind velocity measurement device, for instance, complexity of circuit and difficulty of signal processing, a new ultrasonic wind velocity measurement is put forward based on phase discrimination and a new sensor configuration as well. Thus, a system model is built. Firstly, an equilateral triangle should be constituted by an ultrasonic em...

Building integrated photovoltaic/thermal (BIPV/T) systems serve two purposes – generate electricity and heat ambient air using absorbed solar energy. High wind velocity reduces the efficiency of unglazed transpired solar collectors (UTC). Indeed, wind flow on the collector’s surface reduces the useful heat transferred to the plenum air by effectuating convection losses and suction in the pores;...

Data from a research tower in Lake Ontario are used to study the validity of MoninObukhov scaling in the marine atmospheric boundary layer under various wave conditions. It is found that over pure wind seas, the velocity spectra and cospectra follow established universal scaling laws. However in the presence of swells outrunning weak winds, velocity spectra and co-spectra no longer satisfy univ...

The aerodynamic behavior of a 48’ yacht rig 3D scale model was characterized by means of wind tunnel tests. The experimental program, performed in the Politecnico di Milano Twisted Flow Wind Tunnel, allowed the aerodynamic forces to be characterized using forced motion tests and the aeroelastic behavior of the sail plan to be studied. Preliminary results are presented with reference to the typi...