Deviation of Cup and Propeller Anemometer Calibration Results with Air Density

Abstract

Abstract:The effect of air density variations on the calibration constants of several models of anemometers has been analyzed. The analysis was based on a series of calibrations between March 2003 and February 2011. Results indicate a linear behavior of both calibration constants with the air density. The effect of changes in air density on the measured wind speed by an anemometer was also studied. The results suggest that there can be an important deviation of the measured wind speed with changes in air density from the one at which the anemometer was calibrated, and therefore the need to take this effect into account when calculating wind power estimations.

Studies on Cup Anemometer Performances Carried out at IDR/UPM Institute. Past and Present Research

“…The aerodynamic force on the cups is not acting on their center and even more, the center of the cup is not the average location of the aerodynamic center during one turn of the rotor (this has a quite important effect on the analytical modeling of cup anemometer performances). Additionally, both the effect of the climatic conditions during the calibration process and cup anemometer performance degradation after several months working on the field were analyzed in the works by Pindado et al [23,25]. The results of these analyses were as follows: The output signal of cup anemometers has been also thoroughly studied at IDR/UPM Institute [26,30,31,34].…”

“…With regard to the aforementioned wind speed sensors calibration, this line of work has produced a strong research, mainly focused on cup anemometers (see Figure 1) [22][23][24][25][26][27][28][29][30][31][32][33][34]. Additionally, some relevant research devoted to sonic anemometers has been carried out at IDR/UPM [35][36][37][38][39].…”

On the harmonic analysis of cup anemometer rotation speed: A principle to monitor performance and maintenance status of rotating meteorological sensors

“…(4) can be solved for the stationary state, averaging its value along one turn of the rotor. Then, a direct relationship between the anemometer factor and coefficients c 0 and c x is derived: (12) Using expressions (11), the above equation was finally rewritten in terms of the anemometer factor: °-(-? )H^)…”

“…The present paper is part of the IDR/UPM Institute's research framework on cup anemometer performance, which includes a review of large series of calibrations performed on commercial anemometers [8], the analysis of aging and the climatic effects on anemometer transfer function [11,12], the experimental study of the cups and rotor shapes on anemometer response [13][14][15], and the review and improvement of analytical methods to study anemometer performance in order to have a better understanding of the physics regarding its rotation (aerodynamics, friction, etc. ) [8,[13][14][15][16].…”

Some Developments on Cup Anemometer Aerodynamics

“…For this reason a review of more than 10000 calibrations performed at IDR/UPM started in 2009, focusing on the performance of commercial anemometers, the effect of the calibration accuracy on the AEP (Annual Energy Production) estimations [1], the effect of ageing on the anemometers' performance after calibration [2], and the effect of climatic conditions (changes of temperature, pressure and density) on the anemometer transfer function [3].…”