Characterization of Wind Gusts: A Study Based on Meteorological Tower Observations

Abstract

Accurate information on wind gusts is of critical importance to various practical problems. In this study, observational wind data from high-frequency response (i.e., at a sampling rate of 10 Hz), ultrasonic anemometers instrumented at four different heights (i.e., 10 m, 40 m, 160 m, 320 m) on a weather tower were collected. The observation site featured a typical suburban condition, with no significant obstacles in the immediate proximity. The data were analyzed to identify a total of twelve descriptors of wind gusts, and to find the parent distributions that estimate these parameters well via regression analysis. The results show that the gust parameters in the context of gust magnitude and amplitude with units are best fit by the Weibull model, while non-dimensional parameters in terms of gust factor and peak factor are reasonably assessed by the log-logistic distribution. The uplift time and gust nonsymmetric factor generally exhibit a lognormal distribution, while the Gamma distribution can describe the gust length scale, uplift magnitude and passage time. It is also shown that gust factors increase linearly along with turbulence intensity. Nevertheless, empirical linear formulas given in previous studies tend to over-predict. For the vertical structure of gust descriptors, it is found that the average wind speed, gust amplitude and gust length scale in 10 min monotonically increase with height, whereas the function relationship of gust amplitude, peak factor, gust factor, turbulence intensity, rise amplitude and falling amplitude tends to decrease with height.

The modeling and cascade sliding mode control of a moving mass-actuated coaxial dual-rotor UAV

“…In the trajectorytracking experiment, the system was disturbed by Asinð2tÞ signal to simulate gusts. 21 The maximum wind pressure was 72.9 NÁm À2 , which was equivalent to a strong breeze. The overall MAUAV parameters are listed in Table 1.…”

“…Simultaneously, we recorded the trajectory of the MMC mechanism's centroid in the body coordinate system to verify whether the designed MMC mechanism can complete the control of the fuselage attitude without touching the maximum stroke of the sliders. In the trajectory tracking experiment, the system is disturbed in the form of to simulate gusts [22]. The maximum wind pressure is 72.9N•m -2 , which is equivalent to a strong breeze.…”

Gust Modeling with State-of-the-Art Computational Fluid Dynamics (CFD) Software and Its Influence on the Aerodynamic Characteristics of an Unmanned Aerial Vehicle

“…Gusts are considered to be one of the most dangerous weather phenomena for aircraft. There are plenty of publications characterizing wind gusts, in which data have been obtained during experimental research using different techniques [1][2][3][4][5], as well as during numerical calculations [6]. They show that some gusts have a velocity exceeding 20 m/s, while the time to reach its maximum speed is less than 1 s. Such severe conditions could even cause the crash of a large airliner [7], whereas small and slow flying objects like general aviation aircraft, unmanned aerial vehicles (UAVs) or paragliders are incomparably more sensitive to a turbulent atmosphere [8,9].…”