Fig. 2: Numerical demonstration of the tunable acoustic vortex generation.
From: Tunable acoustic vortex generation by a compact rotating disk
a Summary of simulated phase (first line), and acoustic amplitude (second line) distributions of Ω/2π, 2Ω/2π, 3Ω/2π, and 4Ω/2π Hz at the cross-section z = 40 mm. b Amplitude–frequency spectrum (normalized with the corresponding maximums). The interference of dipole sources from the rotating disk surface will result in an amplitude enhancement at the working frequency of acoustic vortices, fworking = Ω/2π, 2Ω/2π, 3Ω/2π, and 4Ω/2π Hz. These frequencies correspond to the acoustic vortices pressure distributions for l = 1, 2, 3, and 4, respectively.
