Fluidic acoustic oscillator for acoustical analysis of fluid mixtures, has output from nozzle directed onto blade, with distance selected to excite periodic oscillations

摘要

A fluidic acoustic oscillator comprises a nozzle (1), four resonance chambers (4, 7), two outlet channels (3) and at least one sound channel (10) with a transducer attached (11) for measuring time-varying pressures or differential pressures. The output of the nozzle is directed onto the blade of a blade body (2), with the outlet channels on either side. The distance between the nozzle and the blade body is selected so that the fluid jet is excited to form periodic oscillations. Sound waves produced in resonance chambers are converted into harmonic electric signals by dynamic pressure transducers. The sound waves are excited by a flowing gas. The frequency of the sound waves can therefore easily be measured. Since the frequency is dependent on the speed of sound in the fluid, and therefore the material characteristics, the fluid-acoustic oscillator is also suitable for acoustic analysis of fluid mixtures.