An experimental investigation of the ultrasonic system for measurement velocity of gas flows

Abstract

The algorithm for estimation of an error of fixing of the arrival moment of an acoustical signal is given depending on the frequency of the signal and the signal to noise ratio at an output of the receiver. The mathematical expression for calculation of the width of the directional pattern of ultrasonic transducer in accordance with the flow velocity is presented. The experimental results of measurements of flow velocity and speed of sound and also their pulsations in the air flow conduit of 0.5 m in diameter are presented. The possibilities of the measuring system to record velocity pulsations of a gas flow less than 5 mm/s and variations of the sound speed less than 2...3 mm/s, when the mean velocity of the air flow achieve 10 m/s, are shown.