Laboratory setup for determining the influence of inhomogeneities in the water on its acoustic properties and research results

A.N. Grekov, N.A. Grekov, E.N. Sychov, V.J. Mishurov, V.A. Rjazanov, K.A. Kuzmin

 Institute of Natural and Technical Systems, RF, Sevastopol, Lenin St., 28

Email: oceanmhi@ya.ru

DOI: 10.33075/2220-5861-2020-3-114-123

UDC 534.143 

Abstract:

   In order to create new devices for measuring various acoustic characteristics of an aqueous medium (speed of sound, scattering and absorption coefficients), a design of a laboratory multifunctional setup has been proposed to study the effect of microinhomogeneities in water on its acoustic properties. It should be noted that the created laboratory complex is very promising for solving problems such as studying the structure of microinhomogeneities. The article provides a brief analysis of methods for measuring the scattering of ultrasound in a liquid, and also notes the results of recent studies of small-scale irregularities in the ocean and provides links to them. At the research stage, all measurements were carried out on the clouds of microbubbles , located and moving in the liquid. The technique developed by the authors allows to determine, for the mid-frequency range, the design features of primary acoustic transducers with two reflectors, one of which is acoustically semitransparent, and to make correction of the dimensions of highly stable rods made from sital or from the carbon composite, depending on obtaining the necessary spatial and temporal characteristics of the investigated acoustic field. Equations for determining the time windows are given, their values are calculated, and graphs are constructed by which it is possible to determine the volumetric section of sound scattering, without the influence of multiple reflections on the measurement results. After research at the laboratory setup, recommendations were formulated for improving the primary acoustic transducer, the ISZ-1 device, designed to measure the scattering and absorption of ultrasound in situ.

Keywords: multifunctional acoustic stand, ultrasonic scattering, acoustic transducer, time windows, volumetric section, measurement algorithm, acoustic methods, micro-inhomogeneity.

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