Development of an ultrasonic probe for measurements of the wind incidence angle

In this work, a flush ultrasonic system, allowing measurements of the wind angle of incidence up to velocities of 127 m/s, has been developed. The probe consists of an airborne ultrasonic emitter and several ultrasonic receivers placed downstream of the emitter in an arc-shaped arrangement. The first series of tests in an anechoic wind chamber shows that the degradation of the measurement quality with the airflow velocity is related to the increase of the signal-to-noise ratio (SNR). First, the measurement instrumentation has been optimized to have a good transmission and reception of the signals. Then, the signal processing algorithm has been adapted to increase the SNR. Finally, two mock-ups were built to fit existing wind tunnels and allowed measurements to be made as a function of the fluid velocity and the angle of incidence. Results as a function of the angle and for various velocities, as well as modeling of the time of flight, are reported and discussed showing the potential of our system to measure airflow incidence angle.