Cup anemometer response to the wind turbulence-measurement of the horizontal wind variance

Abstract

Abstract. This paper presents some dynamic characteristics of an opto-electronic cup anemometer model in relation to its response to the wind turbulence. It is based on experimental data of the natural wind turbulence measured both by an ultrasonic anemometer and two samples of the mentioned cup anemometer. The distance constants of the latter devices measured in a wind tunnel are in good agreement with those determined by the spectral analysis method proposed in this study. In addition, the study shows that the linear compensation of the cup anemometer response, beyond the cutoff frequency, is limited to a given frequency, characteristic of the device. Beyond this frequency, the compensation effectiveness relies mainly on the wind characteristics, particularly the direction variability and the horizontal turbulence intensity. Finally, this study demonstrates the potential of fast cup anemometers to measure some turbulence parameters (like wind variance) with errors of the magnitude as those deriving from the mean speed measurements. This result proves that fast cup anemometers can be used to assess some turbulence parameters, especially for long-term measurements in severe climate conditions (icing, snowing or sandy storm weathers).

Spectral gap characteristics in a daytime valley boundary layer

“…Following rotation, the wind speed is decomposed into the longitudinal u and lateral v wind speed components. Propeller, as well as cup anemometers, have been reported to be well suited for the study of turbulence, in particular the estimation of horizontal velocity variances (Kristensen, 2000; Yahaya and Frangi, 2004), where they can be as useful as sonic anemometers. This makes them ideal for the study of the spectral gap and the determination of gap scales (Kaimal et al , 1982).…”

Profile of the horizontal wind variance near the ground in near neutral flow – K-theory and the transport of the turbulent kinetic energy

“…So this phenomenon will have no effect on the conclusion of this paper. Even if the cutoff frequency, f co , of the used anemometer is about 2 Hz in temporal mode, its upper frequency limit attains 12 Hz as it is reported in Yahaya and Frangi (2004). In fact, the sampling rate of 1 Hz is an average of the higher frequencies measurement.…”

“…The instrumental error, which stems from the inertial effects of the cup anemometer, has been deeply studied in Yahaya and Frangi (2004). Given the anemometers' distance constants (L≈1.3±0.35 m) and the mean wind velocity (cf.…”

Development of an Unmanned Aerial Vehicle for the Measurement of Turbulence in the Atmospheric Boundary Layer

“…To accurately measure turbulence, one has to resolve the entirety of turbulent scales, which can range from the smallest dynamically important scales (in the order of millimeters) to the largest turbulent scales (in the order of the atmospheric boundary layer thickness). Turbulence data is frequently obtained in the form of temporal information through cup and sonic anemometers, which have a temporal response of 1-2 [2] and 20 Hz respectively and a spatial resolution of 10 s of centimeters.…”