Controllable patterns and streaming of plane acoustic vortex with annular piezoelectric arrays excitation

In this paper, an annular array consisting of 64 piezoelectric ceramics was established to make acoustic vortices. The trapped particles and streaming lines in the fluid chamber were theoretically designed and manipulated in experiment. The acoustic field was simulated by Bessel functions and the principle of Huygens by a hydrophone with the annular array excitation. An fast Fourier transform comparison method was proposed in experiments to get the acoustic vortices and phase patterns. The results showed that the patterns of the acoustic field were much different from each other with the variation of excitation phases and the phase patterns implied the vortices in fluid of the chamber, which were affected by the annular arrays of piezoelectric slice excitation. The research concluded that the trapped area and streaming lines can be manipulated by adjusting the phase of piezoelectric slices and the experimental data were helpful to guide the design of acoustic tweezers.