scholarly journals The Sensitive Element of Acoustic Sensor on Circular Polarized Waves: From Theoretical Considerations towards Perspective Rotation Rate Sensors Design

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 32
Author(s):  
Michail Shevelko ◽  
Andrey Lutovinov ◽  
Aleksandr Peregudov ◽  
Ekaterina Popkova ◽  
Yasemin Durukan ◽  
...  

In this paper, the perspectives of using the features of acoustic wave propagation to design rotation rate sensors (RRS) are discussed. The possibility of developing the solid-state sensitive elements (SE) of RRS on acoustic waves of circular polarization is shown. The theoretical basis of bulk acoustic wave propagation under rotation is given. The direct excitation of circularly polarized acoustic wave (CPAW) is considered, the design of the CPAW emitting transducer is offered. The results of experimental studies that indicated the circular nature of the particle motions in the radiated wave are discussed. The principally new concept of the RRS SE design on CPAW, being able to operate under high vibration and acceleration, is proposed. The experimental results revealed a high correlation with theoretical and numerical predictions and confirmed RRS on CPAW operability.

Author(s):  
Vijay Chatoorgoon ◽  
Qizhao Li

A simple, fundamental experimental study was conducted to better understand acoustic wave propagation is fluid-filled pipes. Three experiments were undertaken: the first with zero flow and a closed outlet end, the second with turbulent flow and an open outlet end and the third with zero flow and an open outlet end. The intent was to obtain data for model comparison and to determine the effect of turbulent flow on the system response. New insights are obtained and reported.


2015 ◽  
Vol 22 (4) ◽  
pp. 823-836 ◽  
Author(s):  
Abo-el-nour N Abd-alladan ◽  
Abdelmonam M Hamdan ◽  
Adel A Almarashi ◽  
Antonio Battista

The objective of this paper is to study the bulk acoustic wave (BAW) propagation velocities in transversely isotropic piezoelectric materials, aluminum nitride, zinc oxide, cadmium sulfide and cadmium selenide. The bulk acoustic wave velocities are computed for each direction by solving the Christoffel’s equation based on the theory of acoustic waves in anisotropic solids exhibiting piezoelectricity. These values are calculated numerically and implemented on a computer by Bisection Method Iterations Technique (BMIT). The modification of the bulk acoustic wave velocities caused by the piezoelectric effect are graphically compared with the velocities in the corresponding non-piezoelectric materials. The results obtained in this study can be applied to signal processing, sound systems and wireless communication in addition to the improvement of surface acoustic wave (SAW) devices and military defense equipment.


2006 ◽  
Vol 21 (supp01) ◽  
pp. 30-34 ◽  
Author(s):  
GERD MANTHEI ◽  
JÜRGEN EISENBLÄTTER ◽  
THOMAS SPIES

Rock salt is a promising material for the detection of acoustic waves generated by interactions of high energy neutrinos. The economical feasibility of an acoustic neutrino detector strongly depends on the spacing between the acoustic sensors. In this paper we report on our experience on acoustic wave propagation and wave attenuation in rock salt in the frequency range of 1 to 100 kHz and some conclusions with respect to the usefulness of rock salt as a neutrino detector. The experience bases on long-term acoustic emission measurements in a salt mine.


1961 ◽  
Vol 1 (04) ◽  
pp. 235-248 ◽  
Author(s):  
J. Geertsma

Abstract Tbe relationsbip between porosity and the speed of propagation of acoustic waves in fluid-saturated porous rocks as measured by the Sonic log and by ultrasonic techniques is analyzed. Biot's continuum theory is used to explain the difference in acoustic wave propagation between a dry and a liquid-saturated porous material. The porosity is a variable in this theory. However, the acoustic wave propagation in the dry rock depends too on porosity, and this dependence is not predicted by the theory. Frequently in dry sandstones, a nearly linear relationsbip between reciprocal acoustic wave velocity and porosity is observed in the low-porosity range. The physics behind this behavior is outlined. An empirical relationship of the form, 1/V ~ A + B ø, applies accordingly for many porous dry rocks, provided the porosity is the only variable. The presence of a liquid in the pores changes the value of B, and this change is found to be in agreement with the Biot theory. The time-average relation introduced some years ago results in an equation of the same type 1/V = ø/Vf + (1 - ø)/Vr - but is not based on a sound physical picture. Still, this relation sometimes predicts approximately correct A and B values. Carbonate rocks with their complicated pore structures sometimes show a different relationship between wave velocity and porosity, unfavorable for log interpretation. Examples are presented. The simultaneous presence of calcite, dolomite and anhydrite, with their different grain densities and matrix compressibilities, complicates acoustic-log interpretation in carbonate rocks still further. Other complicating effects of acoustic-log interpretation are discussed. They are related to the influence of shale streaks and natural fractures on the average wave velocity observed by the logging tool and to the effect of adsorption phenomena on wave propagation in unstressed rocks particularly in sandstones.


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