A new approach to correct yaw misalignment in the spinning ultrasonic anemometer

Abstract

Single-axis ultrasonic anemometers are the modern instruments for accurate wind speed measurements. Despite their widespread and ever increasing applications, little attention has been paid up to now to spinning ultrasonic anemometers that can accurately measure both the wind speed and its direction in a single and robust apparatus. In this study, intensive wind-tunnel tests were conducted on a spinning single-axis ultrasonic anemometer to investigate the yaw misalignment in ultrasonic wind speed measurements during the yaw rotation. The anemometer was rotating inside the test section with various angular velocities, and the experiments were performed at several combinations of wind speed and anemometer angular velocity. The instantaneous angular position of the ultrasonic signal path with wind direction was measured using an angular position sensor. For a spinning anemometer, the circulatory wake and the associated flow distortion, along with the Doppler effect, impart a phase shift in the signals measured by the anemometer, which should be added to the position data for correcting the yaw misalignment. In this paper, the experimental data are used to construct a theoretical model, based on a response surface method, to correct the phase shift for various wind speeds and anemometer rotational velocities. This model is shown to successfully correct the velocity indicated by the spinning anemometer for the phase shift due to the rotation, and can easily be used in the calibration process for such anemometers.

Design and Development of a 5-Channel Arduino-Based Data Acquisition System (ABDAS) for Experimental Aerodynamics Research

“…The common work at the IDR/UPM Institute, related to experimental aerodynamics [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ], cup anemometer calibration and behavior characterization [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ], space components analysis (batteries, solar panels, control systems) [ 23 , 24 , 25 , 26 , 27 , 28 ], and space thermal analysis [ 29 , 30 , 31 , 32 ], has driven the development of the 5-channel Arduino-Based Data Acquisition System (ABDAS) described in the present paper. The purpose of this development is to have a simple but accurate multi-purpose 10–500 Hz sampling rate voltage-data acquisition system capable of being used in different measurement problems from measuring temperatures with thermocouples to wind-tunnel pitot-tube pressure signals.…”