The Effect of a Rotating Medium on Bulk Acoustic Wave Polarization: From Theoretical Considerations to Perspective Angular Motion Sensor Design.

Yasemin Durukan,Sergey Shevchenko,Ekaterina Popkova,Michail Shevelko,Aleksandr Peregudov

doi:10.3390/s20092487

Yasemin Durukan, Sergey Shevchenko + Show 3 more

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https://doi.org/10.3390/s20092487

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Abstract

We study the effects of medium rotation on bulk acoustic wave (BAW) propagation. For a theoretical analysis of the BAW propagation characteristics, a motion equation for the plane harmonic waves propagating orthogonal to the rotation axis of the propagation medium was analytically resolved. We found that during medium rotation, the polarization of the waves becomes elliptical with the ratio of the polarization ellipse axes explicitly proportional to the angular velocity of the medium rotation, thereby opening the way for the design of sensitive elements (SE) for perspective angular motion sensors (AMS). Next, an analytical dependence of the SE informative parameter on the Poisson’s ratio of the acoustic duct material was obtained. The rotation effect on the dispersion of BAW propagation velocity was studied. Two approaches to the perspective SE design were proposed. An experimental study of a specially designed test assembly and SE model demonstrated high correlation with theoretical predictions and provided an estimate of a potential SE. Therefore, we believe that the study of acoustic wave propagation under nonclassical conditions is a promising direction for prospective solid-state AMS on based on BAW polarization effects design.

Highlights

The propagation of acoustic waves in solid media is of theoretical interest, and practical application, for example, in the development of sensitive elements (SE) for prospective solid-state angular motion sensors (AMS) based on both surface and bulk acoustic wave effects [1,2,3,4,5,6,7,8,9]
In the first work devoted to this problem [10], the propagation features of bulk acoustic wave (BAW) excited by a point source in an isotropic elastic medium rotating with a constant angular velocity Ω were considered
For devices that correspond to miniaturization trends, the most promising is the SE built on the principle of detecting the polarization vector rotation in the transverse wave radiated into the direction that coincides with the rotation axis

Summary

Introduction

The propagation of acoustic waves in solid media is of theoretical interest, and practical application, for example, in the development of SE for prospective solid-state AMS based on both surface and bulk acoustic wave effects [1,2,3,4,5,6,7,8,9]. The study of the physics underlying BAW propagation under motion rotation conditions dates back to the 1960s. In the first work devoted to this problem [10], the propagation features of BAW excited by a point source in an isotropic elastic medium rotating with a constant angular velocity Ω were considered. The authors hypothesized that the phase velocity of BAW propagating in an isotropic medium depends on the ratio of the angular velocity of medium rotation Ω and the wave radial frequency ω, which is characterized by the coefficient W.

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