Experimental testing of the estimation of the Doppler shift using complex signals with «good» autocorrelation properties
Experimental testing of the estimation of the Doppler shift using complex signals with «good» autocorrelation properties
A.V. Burenin, V.V. Bezotvetnikh, E.A. Voitenko, M.S. Lebedev, D.S. Strobykin, A.A. Tagiltsev
This paper presents a method of estimating the Doppler shift, which is based on the application of the signal package, consisting of complex signals with "good" autocorrelation properties and operations of autocorrelation (the "convolution" of the received signal with itself) on the receiver. The experimental results validate the approach. Full-scale data obtained are compared with measurements of GPS and similar an acoustic approaches to estimate the Doppler shift.
Show AbstractЭкспериментальное изучение генерации и распространения коротких наносекундных акустических импульсов при высоких давлениях в алмазных наковальнях методом лазерного ультразвука
Экспериментальное изучение генерации и распространения коротких наносекундных акустических импульсов при высоких давлениях в алмазных наковальнях методом лазерного ультразвука
П.В. Зинин,В. Пракапенка, К. Вургесс, Д.Ю. Великовский
В работе рассматривается новый метод измерения скоростей продольных и поперечных волн в непрозрачном слое железа в ячейке алмазной наковальни DAC (diamond anvil cell) при высоких давлениях методом лазерного ультразвука LU (laser ultrasonics) в конфигурации «точечный источник - точечный приемник». Главное преимущество метода в конфигурации «точечный источник – точечный излучатель» для непрозрачных аморфных твердых тел и расплавов в том, что не требуется никаких дополнительных данных для измерения упругих свойств твердых тел под давлением (например, сведений о толщине образца под высоким давлением). В данной работе представлены результаты по изучению спектральных особенностей генерации и приема сдвиговых и продольные волн в железе под высоким давлением в LU-DAC установке.
Show AbstractSources of error in ultrasonic measurements of meteorological parameters in the atmosphere, methods and algorithms for minimization on the basis of the experience of creating industrial weather station AMK-03
Sources of error in ultrasonic measurements of meteorological parameters in the atmosphere, methods and algorithms for minimization on the basis of the experience of creating industrial weather station AMK-03
A.Ya. Bogushevich
Discusses the sources of error when ultrasonic measurements of meteorological measurements in the atmosphere: method related to the physics of ultrasound propagation in the atmosphere; radio signals that occur when recording and processing electrical signals equipment, mechanical, due to the influence of the construction of the device on the wind flow and wrapping thanks to its temperature changes and others. Mathematical algorithms and methods are described that allow you to minimize measurement errors. The presentations are illustrated with materials from industrial development experience weather station AMK-03.
Show AbstractExperience in using of hydroacoustic oscillator to study the variability of sea environment on stationary path of steep shelf
Experience in using of hydroacoustic oscillator to study the variability of sea environment on stationary path of steep shelf
V.P. Elistratov, G.V. Kenigsberger, V.I. Moiseenkov, A.N. Serebryany
Results of investigations of hydroacoustic oscillator charateristics on stationary 125-meter track in coastal zone of the Black Sea for two rays conditions of the sea structure are presented. The impact of variability of hydrophysical parameters of environment on mode of operation of oscillator are discussed.Possibility of using the oscillator as a tool for monitoring of the sea medium is discussed.Results of temperature measurements of sea environment by termistor string during oscillator operation is shown.
Show AbstractNonlinearity of shear oscillations for visco-elastic fluid
Nonlinearity of shear oscillations for visco-elastic fluid
V.V. Grishaev, I.B. Esipov, М.А. Mironov
Heavy raw oil modules slowly vary in proportion to log of time. The recent research of complex shear module dependence on strain amplitude reveals log time increasing of nonlinear parameter for sample of raw oil. Experiments have been done at the rotation rheometer in the mode of small torsional oscillations. Experiment showed the complex shear module linearly decreases with amplitude of shear excitation increase and that could be if the value of shear module of the oil linearly varies with strain modulus. Results of the first three harmonics amplitudes analysis for visco-elastic response on both amplitude excitation and time are presented as well.
Show AbstractLong-range acoustic propagation in the Barents Sea
Long-range acoustic propagation in the Barents Sea
R.A. Vadov, N.K. Abakumova
In the Barents Sea in summer-autumn requirements repeatedly per different years (since 1972) an experience on long-range diffusion of explosive and tone signals including of re-search courts of the Institute of Acoustic of Russian Academy of Sciences were put. On ma-terials of these experience the analysis of spatial - energy and time frame of sound fields is conducted, losses of sound energy in ground adjournment are estimated and its frequency dependence, the opportunities of build-up of acoustic model of a bottom compounded with effects of conducted experience are discussed.
Show AbstractAcoustic diagnostics of «solid-state combustion» processes in organic crystal mixes
Acoustic diagnostics of «solid-state combustion» processes in organic crystal mixes
E.G. Klimchuk, A.L. Parakhonsky
With the help of designed experimental device and measurement technique an emission of sound waves (acoustic emission) is discovered and registered during «solid-state combustion» in the mixes of organic crystals. The spektral-correlation analysis of the registered acoustic signals is offered as a new effective method of research of the combustion features caused by the moving of the reacting environment. The processes accompanying combustion are in-situ diagnosed and identified with its help; their space-time distribution in the reacting sample is detailed. The local reaction germs in a green mix and thermal cracking of organic crystals are found out. Dynamics of formation of bubbles and porous structure of products in the reaction front and during their cooling is studied. The moment of changing of chemical reaction mode is established. Correlation between the structure of synthesized condensed products of combustion and peculiarities of acoustic emission is shown. That fact causes principal possibility of acoustic certification of «solid-state combustion» products.
Show AbstractSeismoacoustic wavefield transformation through heterogeneity of lower atmosphere
Seismoacoustic wavefield transformation through heterogeneity of lower atmosphere
D.A. Presnov. A.V. Razin. A.L. Sobisevich. A.S. Shurup
Problem of seismoacoustic wave’s excitation in a layered system composed of homogeneous isotropic elastic half-space – homogeneous fluid layer – fluid half-space, by harmonic force acting on elastic medium is considered. This system simulates Earth, near-surface layer of air with sharp temperature contrast and atmosphere. Expressions for wavefields obtained in the form of Fourier – Bessel integrals. Focus is concentrated on study of acoustic waves in the fluid half-space. Approximate solution valid on large (in comparison with the wavelength) distances from the seismic source is derived. We examine the case where sound speed in the layer higher than in the fluid half-space (this holds antiwaveguide propagation of acoustic waves), and the case of low-velocity layer, when near-surface refraction waveguide occurs. Acoustic waves average by period radiation powers obtained in integral expressions for three different areas of fluid half-space. Numerical analysis of the radiation power is conducted in the case of high-velocity and low-velocity near-surface layers. Results of data processing from field experiments on acoustic and seismic signals detection during industrial explosions in quarry (northwest Russia) presented.
Show AbstractSound intensity fluctuations resulting from mode coupling in shallow-water nonlinear internal waves
Sound intensity fluctuations resulting from mode coupling in shallow-water nonlinear internal waves
V.A. Grigorev, B.G. Katsnelson, J.F. Lynch
The analysis is carried out for the low frequency (300±30 Hz) intensity fluctuations of the sound pulses propagating in the shallow water waveguide in the presence of nonlinear internal waves (NIW) in the experiment Shallow Water 2006 (Atlantic shelf of USA). Signals were being received by vertical line array (distance to the source ~20 km). NIW train was placed entirely inside of an acoustic track during time period of the sound radiation. Angle between wave front of NIW and direction of an acoustic track was ~10°. Theoretical modeling of spectrum of fluctuations were obtained using theory of authors for the sound fluctuations due to mode coupling. The main feature of the theory is existence of the so called «predominating frequency», corresponding to the spectral component of maximal amplitude. Comparison of modeling results and experimental data allows us to interpret position of the maximum in the spectrum as predominating frequency. Contribution of horizontal refraction is discussed as well.
Show AbstractThe change of rheological properties of high viscosity of the structured oil when ultrasonic processing
The change of rheological properties of high viscosity of the structured oil when ultrasonic processing
I.N. Evdokimov , N.Yu. Eliseev, A.A. Fesan
In the course of the research was conducted short-term and long-term ultrasonic treatment samples of high viscosity structured oil content of asphaltenes 15-16%. The results of measurements and calculations for short ultrasonic processing of high-viscosity oil show that the rheological dependencies there are intervals of shear rate, showing a decrease or increase in viscosity. Prolonged ultrasonic treatment does not lead to qualitative changes in the colloid-dispersed structure. After ultrasonic treatment of the structured oil can be observed as positive effects (reduced viscosity) and negative effects (increase in viscosity, precipitation, clogging of the pore space of the reservoir). For each case (individual type of oil, reservoir conditions, the power source of ultrasound), it is necessary to determine the appropriate processing time for achieving maximum positive effect.
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