Iungo, Giacomo V.
Permanent URI for this collectionhttps://hdl.handle.net/10735.1/4790
Giacomo Iungo is currently an Associate Professor of Mechanical Engineering and head of the WindFluX (Wind, Fluids, and eXperiments) Lab. His research interests include wind energy, flow instability, bluff body aerodynamics; atmospheric boundary layer, reduced order models; signal processing; wind tunnel design; experimental fluid mechanics; and wind LiDAR technology.
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Browsing Iungo, Giacomo V. by Author "Alan Brewer, W."
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Item Identification of Tower-Wake Distortions Using Sonic Anemometer and Lidar Measurements(Copernicus GmbH, 2018-08-31) McCaffrey, K.; Quelet, P. T.; Choukulkar, A.; Wilczak, J. M.; Wolfe, D. E.; Oncley, S. P.; Alan Brewer, W.; Debnath, Mithu; Ashton, Ryan; Iungo, Giacomo V.; Lundquist, J. K.; 0000-0002-0990-8133 (Iungo, GV); Debnath, Mithu; Ashton, Ryan; Iungo, Giacomo V.The eXperimental Planetary boundary layer Instrumentation Assessment (XPIA) field campaign took place in March through May 2015 at the Boulder Atmospheric Observatory, utilizing its 300 m meteorological tower, instrumented with two sonic anemometers mounted on opposite sides of the tower at six heights. This allowed for at least one sonic anemometer at each level to be upstream of the tower at all times and for identification of the times when a sonic anemometer is in the wake of the tower frame. Other instrumentation, including profiling and scanning lidars aided in the identification of the tower wake. Here we compare pairs of sonic anemometers at the same heights to identify the range of directions that are affected by the tower for each of the opposing booms. The mean velocity and turbulent kinetic energy are used to quantify the wake impact on these first-and second-order wind measurements, showing up to a 50 % reduction in wind speed and an order of magnitude increase in turbulent kinetic energy. Comparisons of wind speeds from profiling and scanning lidars confirmed the extent of the tower wake, with the same reduction in wind speed observed in the tower wake, and a speed-up effect around the wake boundaries. Wind direction differences between pairs of sonic anemometers and between sonic anemometers and lidars can also be significant, as the flow is deflected by the tower structure. Comparisons of lengths of averaging intervals showed a decrease in wind speed deficit with longer averages, but the flow deflection remains constant over longer averages. Furthermore, asymmetry exists in the tower effects due to the geometry and placement of the booms on the triangular tower. An analysis of the percentage of observations in the wake that must be removed from 2 min mean wind speed and 20 min turbulent values showed that removing even small portions of the time interval due to wakes impacts these two quantities. However, a vast majority of intervals have no observations in the tower wake, so removing the full 2 or 20 min intervals does not diminish the XPIA dataset. © 2017 Author(s).Item Vertical Profiles of the 3-D Wind Velocity Retrieved from Multiple Wind Lidars Performing Triple Range-Height-Indicator Scans(Copernicus GmbH, 2018-08-20) Debnath, Mithu; Iungo, Giacomo V.; Ashton, Ryan; Alan Brewer, W.; Choukulkar, A.; Delgado, R.; Lundquist, J. K.; Shaw, W. J.; Wilczak, J. M.; Wolfe, D.; 0000-0002-0990-8133 (Iungo, GV); Debnath, Mithu; Iungo, Giacomo V.; Ashton, RyanVertical profiles of 3-D wind velocity are retrieved from triple range-height-indicator (RHI) scans performed with multiple simultaneous scanning Doppler wind lidars. This test is part of the eXperimental Planetary boundary layer Instrumentation Assessment (XPIA) campaign carried out at the Boulder Atmospheric Observatory. The three wind velocity components are retrieved and then compared with the data acquired through various profiling wind lidars and high-frequency wind data obtained from sonic anemometers installed on a 300 m meteorological tower. The results show that the magnitude of the horizontal wind velocity and the wind direction obtained from the triple RHI scans are generally retrieved with good accuracy. However, poor accuracy is obtained for the evaluation of the vertical velocity, which is mainly due to its typically smaller magnitude and to the error propagation connected with the data retrieval procedure and accuracy in the experimental setup.