Control of directivity patterns of electroacoustical transducers when measuring gas flow parameters

Abstract

It is shown that when measuring gas flow velocity and other parameters in the velocity range v= 0.05…60m/s it is purposive to use the electroacoustical transducers with the controllable directional patterns. The algorithms for calculation of the additional angles of turn of directional patterns of electroacoustical transducers are presented. These algorithms are valid when the gas flow velocity, flow profile and the angle of flow probing are changed. By modeling of the drift of acoustical signals in the airflow it is shown that the drift angles of acoustical signals may achieve j = 9⁰-10⁰ and is increased with grow of flow velocity and flow probing angle. It is revealed that the influence of the gas flow profile to the additional turn angles of electroacoustical transducers is comparatively insignificant when the gas flow profile is turbulent. In such case the additional turn angles of transducers may be calculated by using algorithms for the flat gas flow profile. The block diagram of the system for control of directional patterns of electroacoustical transducers is presented. It enables the different control of directional patterns of transducers when radiating and receiving acoustical signals.