Design and simulation of acoustic vortex wave arrays for long-range underwater communication

Abstract

The formation and propagation of acoustic vortex waves have been of increasing interest for multiple applications, namely, underwater acoustic communications. Several methods have been presented to form these vortices in underwater environments; however, their performance and propagation over long distances is largely unstudied. Understanding the long-distance propagation of these waves is vital to enhancing their usefulness as an added degree of freedom in underwater acoustic communications systems. In this work, the ray tracing algorithm of bellhop is used to investigate the design parameters of vortex wave transducer and receiver arrays consisting of multiple rings of independently controlled transducers and simulate their performance.

Ray tracing model for long-range acoustic vortex wave propagation underwater

“…To this point, the examples presented have been limited to relatively simple environments to illustrate the methods and show their efficacy. As presented in Kelly and Shi, 2023), these methods may also be applied effectively to more realistic environments. Here an even more complex environment is presented to illustrate the robustness of these methods.…”

“…To illustrate the effects of refraction, the vortex is depicted at a range of 500 m for an array offset by 50 m from the duct center. Based on the results of Kelly and Shi (Kelly and Shi, 2023), we also maintain the rings of the array in phase with the innermost ring for the improved performance. Eq.…”

“…The non-diffracting characteristic of a Bessel beam is limited by its aperture (Durnin et al, 1987), therefore, these defining characteristics do not apply over long ranges, especially in inhomogeneous environments. While several methods have been presented to form vortex waves, this model relies on arrays like those presented in Shi et al (Shi et al, 2017) and Kelly and Shi (Kelly and Shi, 2023), which are comprised of concentric rings of N transducers (Cain and Umemura, 1986;Umemura and Cain, 1989). An array configuration consisting of 3 concentric rings of radii 5, 10, and 15 wavelengths with phases determined using Eq.…”

“…The model presented below was first introduced in and explored further in Kelly and Shi (Kelly and Shi, 2023). It relies on the assumption that each of the transducers in the array can be approximated as an individual point source, which allows for visualization of vortex propagation either as range vs. depth (perpendicular to the vortex) or the wavefront plane (parallel to the vortex).…”

Underwater double vortex generation using 3D printed acoustic lens and field multiplexing

“…There are several challenges associated with the incorporation of multiple vortices in a simple device to broaden its functionality. These include the necessity for complicated transducer arrays [36][37][38] and potential operational limitations dictated by factors such as particle size and the propagation medium. These factors can lead to acoustic wave reflection and refraction, resulting in the distortion of the acoustic beam shape, 39,40 and the introduction of a focusing mechanism further complicates their operation.…”