RU2536782C1 - Hydroacoustic directional waveguide converter - Google Patents

Abstract

FIELD: physics, acoustics.

SUBSTANCE: invention relates to hydroacoustics and specifically to designing a directional waveguide converter, capable of operating in a frequency band for hydroacoustic means for various purposes, including towed means, as antenna systems for: sonar, communication, navigation, profiling, acoustic tomography, illumination of an underwater environment etc. The hydroacoustic directional waveguide converter comprises a gas-filled pressure-resistant housing insulated from the external environment, which holds an active element in the form of a reinforced rod-shaped piezoelectric bundle which is rigidly mated with an elastic cylindrical waveguide through a fastening-sealing end piece in the form of a cup, which provides flexible connection with the pressure-resistant housing. The waveguide converter is made of a composite material, e.g. ebonite and brass, and is a periodic thin-layer structure consisting of identical, alternating links of equal thickness; wherein the orientation of the waveguide links made of the composite material is perpendicular to the axis of the waveguide, and the waveguide is reinforced with thin elastic rods made of, for example, titanium.

EFFECT: improved process characteristics of the hydroacoustic converter, particularly narrower beam patterns, high sensitivity, radiation power, higher strength of the structure of the converter and reliability thereof, along with the reduced weight and size of the waveguide.

2 cl, 5 dwg

Description

The invention relates to the field of hydroacoustics, in particular to the design of a directional waveguide transducer capable of operating in the frequency band for hydroacoustic devices for various purposes, including towed ones, as antenna systems: sonar, communication, navigation, profiling, acoustic tomography, and underwater lighting etc.

Known sonar emitter containing a rod piezoelectric element with overlays, reinforced with a hairpin, where the back plate is used to lower the resonant frequency of the emitter, and the front one is used for radiation into the working medium [1]. The disadvantages of such a radiator are low power, low sensitivity and electro-acoustic efficiency, weak directivity, narrow band of operating frequencies.

Known sonar directional transducer SEFAR, in which, unlike the known transducer [1], the front conical plate is replaced by an elastic ribbed rod waveguide made of brass [2, 3]. A ribbed rod waveguide is the main part of the emitter and is excited by a piezoceramic titanate-barium quarter wave cylinder. The waveguide provides better matching of the transducer with the medium, axial direction. The disadvantages of the emitter are: large weight and size parameters of the waveguide, a narrow band of operating frequencies, restrictions on radiated power, a high level of back radiation, an inefficient excitation system.

A different type of transducers is known, according to the physical principle of action, related to waveguide emitters [4]. This waveguide transducer contains a set of N coaxially located, identical piezoelectric rings with acoustically flexible gaskets between their ends, an acoustic screen located on the outer surface of the rings, a signal generator, a filter with an adjustable transmission coefficient, an electronic control system for the distribution of amplitudes and phases over the transducer elements. A cylindrical waveguide in which a wave traveling in two opposite directions is excited is formed by the internal cavity of the piezoelectric ring system filled with liquid; Due to the incoherent addition of acoustic waves traveling in the opposite direction, the unidirectionality of radiation through one of the ends is achieved. A filter is introduced into the excitation circuit, which allows to significantly expand the passband.

The disadvantages of the transducer are: potentially low radiated power, due to the significantly lower strength of the liquid, compared with the solid material of the waveguide, weak directivity, low electro-acoustic efficiency and sensitivity; the complexity of manufacturing and tuning the system of excitation and phasing rings; high cost and low reliability.

Known hydroacoustic directional cylindrical waveguide transducer, which by the combination of features, technical nature and the technical result achieved is closest to the proposed invention, is selected as a prototype [5].

,The prototype converter is structurally simple and consists of a reinforced rod piezoelectric packet and an elastic cylindrical ebonite waveguide providing axial radiation. The principle of operation of the waveguide transducer is based on the fact that a sound field is formed by a leaking elastic wave propagating with a phase velocity c exceeding the speed of sound in a liquid with ₀ , then its energy is radiated through the side surface of the waveguide into the environment at a certain angle

,

where α is the radius of the cylindrical waveguide, ϖ is the operating frequency [5].

It is known from the prior art that the presence of an elastic cylindrical waveguide in a design provides a well-known transducer with a number of advantages: high sensitivity, electro-acoustic efficiency, radiated power, provides the formation of directional acoustic fields with a low level of side lobes with the best mass-dimensional parameters of the radiating structure. The known waveguide converter is reversible, demonstrates high noise immunity to isotropic noise and a low level of hydrodynamic noise arising when towing this converter [5].

The disadvantages of the converter are: the impossibility of forming narrow axial radiation patterns with a width of less than 45º, the limited mechanical strength of the ebonite waveguide, which is especially manifested when it is necessary to design low-frequency antennas.

The problem to which the claimed invention is directed is expressed in the development of the design of a reversible hydroacoustic waveguide directional transducer, characterized by the required high directivity, increased mechanical strength, reduced weight and size characteristics.

The technical result of the claimed device is to improve the technical characteristics of the converter: achieving narrower radiation patterns, high sensitivity, radiation power, increasing the strength, reliability of its design, along with reducing the overall characteristics of the waveguide.

, где $${\tilde{h}}_2=h_2/(h_1-h_2)$$

.To solve this problem, a hydroacoustic directional waveguide transducer is proposed, containing a gas-filled strong housing isolated from the external environment, in which an active element is placed, consisting of a packet of longitudinally polarized piezo washers, electrically connected in parallel, assembled on a tightening pin, placed between reinforcing limit washers and tightened by a nut; the transducer housing is loaded onto a cylindrical waveguide through a glass-shaped fastening and sealing plate, which simultaneously provides a rigid connection of the piezoelectric packet with an elastic cylindrical waveguide and flexible connection with a robust housing. At the same time, new features were introduced into the design of the elastic cylindrical waveguide, namely, it is made of composite, which is a periodic fine-layered structure in the form of identical units of equal thickness h = h ₁ + h ₂ , where h ₁ and h ₂ are the thicknesses of layers of homogeneous materials, of which consists of a composite, for example, of ebonite and brass with a relative layer thickness of the latter $${\tilde{h}}_2=(0.1-0.15)$$

where $${\tilde{h}}_2={\mathrm{<figure-callout\; id="2"\; label="h"\; filenames="00000030.png"\; state="\{\{state\}\}">h</figure-callout>}}_2/(h_{\mathrm{one}}-h_2)$$

.

In addition, this problem is solved by the fact that the orientation of the links is perpendicular to the axis of the waveguide, and also by the fact that the waveguide is reinforced with thin elastic rods, for example, of titanium.

, или их акустических параметров, а также ориентация композита в акустическом поле позволяют существенно расширить диапазон величин их эффективных или усредненных акустических характеристик, таких как плотность, скорости продольных и поперечных волн соответственно, $${\tilde{\rho }}_{эф}$$

, $${\widetilde{С}}_l$$

, $${\widetilde{С}}_t$$

[6-7]. Как следует из выражения (1), для получения более узких, с шириной (20-30)º, характеристик направленности, фазовая скорость распространения волны должна быть замедлена до величины с_φ≈(1505-1550) м/с. Проведенными расчетами показано и опытным путем подтверждено, что указанное замедление фазовой скорости достигается при перпендикулярной ориентации слоев композитного материала относительно оси волновода, а величина скорости зависит от рабочей частоты, геометрии волновода, от влияния системы армирования и акустической нагрузки.It is known that in composite layered materials even small changes in the volume concentrations of components characterized by the parameter $${\tilde{h}}_2$$

, or their acoustic parameters, as well as the orientation of the composite in the acoustic field, can significantly expand the range of values of their effective or average acoustic characteristics, such as density, longitudinal and shear wave velocities, respectively, $${\tilde{\rho }}_{\mathrm{uh}f}$$

, $${\widetilde{\mathrm{FROM}}}_l$$

, $${\widetilde{\mathrm{FROM}}}_t$$

[6-7]. As follows from expression (1), in order to obtain narrower directivity characteristics with a width of (20-30) º, the phase velocity of wave propagation must be slowed down to a value with _φ ≈ (1505-1550) m / s. The calculations showed and experimentally confirmed that the indicated phase velocity deceleration is achieved with a perpendicular orientation of the composite material layers relative to the axis of the waveguide, and the speed depends on the operating frequency, waveguide geometry, the influence of the reinforcement system and acoustic load.

The essence of the invention is illustrated by drawings and diagrams presented in figure 1-5:

- figure 1 shows a schematic design of the proposed sonar waveguide directional transducer;

- figure 2 shows the dependence of the phase velocity in composite waveguides made of ebonite and metal on the layer thickness of the latter for different metals: brass, steel, aluminum, curves 1, 2, 3, respectively.

для разного объемного состава: $${\tilde{h}}_2=0.12$$

(кривая 3), $${\tilde{h}}_2=0.1$$

(кривая 2), а также композита (кривая 1) с относительным объемным содержанием латуни $${\tilde{h}}_2=0.1$$

, армированного тонкими титановыми стержнями с объемным содержанием $$\nu =\raisebox{1ex}{$s_m$}\!\left/ \!\raisebox{-1ex}{$s_{в}$}\right.=0.04$$

, где s_m, s_в соответственно поперечное сечение стержней и волновода;- figure 3 shows the calculated dispersion dependence of the phase velocity in a composite waveguide of ebonite and brass immersed in a liquid, on the dimensionless frequency parameter $$\tilde{x}$$

for different volumetric composition: $${\tilde{h}}_2=0.12$$

(curve 3) $${\tilde{h}}_2=0.1$$

(curve 2), as well as a composite (curve 1) with a relative volume content of brass $${\tilde{h}}_2=0.1$$

reinforced with thin titanium rods with volumetric content $$\nu =\raisebox{1ex}{$s_m$}\!\left/ \!\raisebox{-1ex}{$s_{\mathrm{at}}$}\right.=0.04$$

where s _m , s _are respectively the cross section of the rods and the waveguide;

;- figure 4 shows the frequency dependence of the coefficient of radiation attenuation in an armored waveguide made of hard rubber - brass at $${\tilde{h}}_2=0.1$$

;

- figure 5 shows the radiation patterns of the mock waveguide transducer with different waveguides: a) made of ebonite, b) a composite waveguide made of ebonite and brass at frequencies: 3200 Hz (curve 1), 2500 Hz (curve 2), 2200 Hz ( curve 3).

(табл., фиг.2).Mathematical calculations based on the theory of fine-layered periodic anisotropic compositional media and waveguide sound propagation [5-6], it was found that the optimal composition of the composite, providing the specified value with _φ , is a structure of ebonite and brass with a thickness of the brass layer $${\tilde{h}}_2=0.1$$

(tab., figure 2).

, выбираемой в зависимости от заданной ширины диаграммы направленности и требуемой прочности волновода. Армирование композитного волновода тонкими упругими стержнями, например, из титана, увеличивает его упругость и повышает фазовую скорость до требуемой величины с_φ≈(1505-1550) м/с в области выбранных рабочих значений частотного параметра $$\tilde{x}=\raisebox{1ex}{$a\varpi $}\!\left/ \!\raisebox{-1ex}{${\tilde{c}}_t$}\right.$$

, когда волна становится вытекающей. Последнее подтверждают расчетные данные дисперсионной зависимости фазовой скорости от безразмерного частотного параметра $$\tilde{x}$$

в композитном волноводе, $$\tilde{x}=\raisebox{1ex}{$a\varpi $}\!\left/ \!\raisebox{-1ex}{${\tilde{c}}_t$}\right.$$

и погруженном в жидкость, для разного объемного состава (фиг.3): $${\tilde{h}}_2=0.12$$

(кривая 3), $${\tilde{h}}_2=0.1$$

(кривая 2), а также композита (кривая 1) с относительным содержанием латуни $${\tilde{h}}_2=0.1$$

, который армирован тонкими титановыми стержнями с объемным содержанием $$\nu =\raisebox{1ex}{$s_m$}\!\left/ \!\raisebox{-1ex}{$s_{в}$}\right.=0.04$$

, где s_m, s_в - соответственно суммарное поперечное сечение армирующих стержней и волновода. Улучшение габаритных характеристик волновода, сокращение его длины, за счет использования мелкослоистого композиционного материала при изготовлении волновода, подтверждается данными частотной зависимости радиационного коэффициента затухания (фиг.4). Представленные данные подтверждают более эффективное излучение энергии бегущей волны в жидкость, чем в волноводе, изготовленном из эбонита того же радиуса. Отрицательным свойством композитного материала является то, что он имеет более высокую, чем эбонит, плотность, на это указывают данные таблицы. Однако это не приводит к увеличению массы заявляемого преобразователя по сравнению с прототипом, так как он имеет меньшую длину и радиус волновода. Как показывают сравнительные вычисления массогабаритных параметров волноводов, выполненные по данным фиг.4, таблицы и работы [5], рассчитанных на одинаковую рабочую частоту при равных значениях безразмерного частотного параметра $$\tilde{x}$$

и заданных уровнях боковых лепестков, длина волновода заявляемого преобразователя, выполненного из композита, сотоящего из эбонита и латуни с объемным содержанием $${\tilde{h}}_2=0.1$$

, в 1,25 раз меньше, радиус в 1,2 раза меньше, масса в 1,14 раза меньше, чем у преобразователя-прототипа. Кроме того, при этом улучшаются следующие технические характеристики преобразователя: повышается механическая прочность, уменьшается ширина диаграммы направленности с 45° до (20-25)°, увеличивается чувствительность не только за счет сужения диаграммы направленности, но и благодаря лучшему согласованию пьезопакета с композитным волноводом, имеющем более высокое, чем волновод из эбонита, удельное сопротивление (соответственно $$2,8\cdot {10}^6\raisebox{1ex}{$кг$}\!\left/ \!\raisebox{-1ex}{${м}^2с$}\right.$$

и $$2,02\cdot {10}^6\raisebox{1ex}{$кг$}\!\left/ \!\raisebox{-1ex}{${м}^2с$}\right.$$

).For the first time, it was found that improving the technical characteristics of the converter — achieving narrower radiation patterns and high sensitivity — is possible by replacing the material from which the waveguide is made, which is confirmed by the data in the table and is illustrated by curves 1-3 (Fig. 2), which show the dependence of the phase velocity from the relative thickness of the metal layer of the waveguide. The data presented indicate that the finely layered two-component orthotropic composite material of the optimal composition found has acoustic parameters that can reduce the rod velocity from (1685-1715) m / s (prototype waveguide) to 1489 m / s (declared waveguide) by replacing ebonite in prototype waveguide for composite material, namely ebonite - brass with a thickness of the brass layer $${\tilde{h}}_2=\left(0.1-0.15\right)$$

, selected depending on the given width of the radiation pattern and the required strength of the waveguide. Reinforcing a composite waveguide with thin elastic rods, for example, of titanium, increases its elasticity and increases the phase velocity to the desired value with _φ ≈ (1505-1550) m / s in the range of the selected operating values of the frequency parameter $$\tilde{x}=\raisebox{1ex}{$a\varpi $}\!\left/ \!\raisebox{-1ex}{${\tilde{c}}_t$}\right.$$

when the wave becomes leaking. The latter is confirmed by the calculated data of the dispersion dependence of the phase velocity on the dimensionless frequency parameter $$\tilde{x}$$

in a composite waveguide, $$\tilde{x}=\raisebox{1ex}{$a\varpi $}\!\left/ \!\raisebox{-1ex}{${\tilde{c}}_t$}\right.$$

and immersed in a liquid for different volumetric composition (figure 3): $${\tilde{h}}_2=0.12$$

(curve 3) $${\tilde{h}}_2=0.1$$

(curve 2), as well as a composite (curve 1) with relative brass content $${\tilde{h}}_2=0.1$$

which is reinforced with thin titanium rods with volumetric content $$\nu =\raisebox{1ex}{$s_m$}\!\left/ \!\raisebox{-1ex}{$s_{\mathrm{at}}$}\right.=0.04$$

, where s _m , s _in - respectively, the total cross section of the reinforcing rods and the waveguide. Improving the overall characteristics of the waveguide, reducing its length, through the use of a finely layered composite material in the manufacture of the waveguide, is confirmed by the frequency dependence of the radiation attenuation coefficient (Fig. 4). The presented data confirm a more efficient radiation of the traveling wave energy into the liquid than in a waveguide made of ebonite of the same radius. The negative property of the composite material is that it has a higher density than ebonite, as indicated by the data in the table. However, this does not lead to an increase in the mass of the inventive Converter in comparison with the prototype, since it has a shorter length and radius of the waveguide. As shown by the comparative calculations of the mass-dimensional parameters of the waveguides, performed according to Fig. 4, tables and works [5], designed for the same operating frequency with equal values of the dimensionless frequency parameter $$\tilde{x}$$

and given levels of side lobes, the length of the waveguide of the inventive transducer made of a composite, consisting of ebonite and brass with a volumetric content $${\tilde{h}}_2=0.1$$

, 1.25 times smaller, radius 1.2 times smaller, mass 1.14 times less than that of the prototype converter. In addition, the following technical characteristics of the converter are improved: mechanical strength increases, the radiation pattern width decreases from 45 ° to (20-25) °, sensitivity increases not only due to narrowing the radiation pattern, but also due to better matching of the piezoelectric packet with the composite waveguide, having a higher resistivity than ebonite waveguide (respectively $$2,8\cdot {10}^6\raisebox{1ex}{$\mathrm{to}\mathrm{<figure-callout\; id="2"\; label="g\; m"\; filenames="00000030.png"\; state="\{\{state\}\}">g\; </figure-callout>}$}\!\left/ \!\raisebox{-1ex}{$m^{}$}\right.$$

and $$2,02\cdot {10}^6\raisebox{1ex}{$\mathrm{to}\mathrm{<figure-callout\; id="2"\; label="g\; m"\; filenames="00000030.png"\; state="\{\{state\}\}">g\; </figure-callout>}$}\!\left/ \!\raisebox{-1ex}{$m^{}$}\right.$$

)

Distinctive features of the claimed hydroacoustic directional waveguide transducer are:

,- manufacture of a waveguide from a composite fine-layered material, which is a periodic fine-layered medium in the form of identical units of equal thickness h = h ₁ + h ₂ , where h ₁ and h ₂ are the thicknesses of the layers of homogeneous materials that make up the composite, for example, ebonite and brass , with the relative thickness of the latter, where $${\tilde{h}}_2={\mathrm{<figure-callout\; id="2"\; label="h"\; filenames="00000030.png"\; state="\{\{state\}\}">h</figure-callout>}}_2/(h_{\mathrm{one}}+h_2)$$

,

- the location of the links of the finely laminated composite material perpendicular to the axis of the waveguide. Such a composite waveguide provides the necessary for obtaining narrow radiation patterns to slow down the phase velocity of a normal wave and reduce the size of the waveguide,

- reinforcing the waveguide with thin elastic rods that increase the mechanical strength of the transducer and increase the phase velocity to the desired value.

The introduction of each new distinctive feature in conjunction with the known essential features of the prototype transducer provides a solution to the problem, namely: the design of a reversible hydroacoustic waveguide directional transducer is developed, characterized by a higher directivity, sensitivity, reduced weight and size characteristics and with increased mechanical strength.

Structurally, the hydro-acoustic waveguide directional emitter is simple and represents a rod active element - piezoelectric package 4, loaded onto a cylindrical composite finely layered ebonite-brass waveguide 1. The active element is insulated from the external environment by a robust housing 2 with a cover 3. Rod active element 4, consisting of piezo washers longitudinal polarization, electrically connected in parallel and excited in phase, assembled on a stud 7 with a centering sleeve 8 between the reinforcing restrictive shafts 5 and 6 and tightened with nut 10. Between the piezoelectric packet 4 and the waveguide 1 there is a cylindrical mounting and sealing plate in the form of a glass 9, which provides a rigid docking of the piezoelectric packet 4 with the waveguide 1 and flexible with a strong body 2. The plate 9 is connected to the waveguide 1 with an adhesive seam 17 and coupler bolts 20 with filling the threaded connection with glue. The piezoelectric packet is rigidly docked to the waveguide through the lining 9 using adhesive joints reinforced with a threaded joint at the end of the reinforcing stud 7 of the transducer. After docking the transducer with the waveguide, a strong housing 2 is installed. The sealing flexible rings 14 and gasket 18 serve for acoustic isolation between the housing and the waveguide. On the back of the case, a centering disk 12 is mounted on the shank of the reinforcing pin 7, which abuts against a step on the wall of the case and, using the nut 13, fixes the converter inside the case, while centering its position relative to the longitudinal axis. The acoustic isolation of the disk 12 from the housing is provided by flexible rings 15. Electric wires 11 are installed on the centering disk through which the piezoelectric package is connected to the cable electrically. The end face of the durable housing is hermetically closed by a cover 3, which is sealed by a flexible ring 16. The housing and the base of the waveguide are filled with an elastic compound, which forms a cylindrical protective cover 19.

The proposed emitter operates as follows. In the radiation mode, when the operating voltage is applied to the rod piezoelectric packet 4, longitudinal mechanical vibrations arise in it, which through the cup-type plate 9 in turn excite vibrations in the cylindrical elastic waveguide 1 acoustically connected with it in the form of a symmetric longitudinal normal wave. A normal wave propagating with a phase velocity C _φ / C ₀ is radiated into the surrounding space through the lateral surface of the composite waveguide under the direction γ _max (ϖ), forming a directional acoustic field, the form of which depends on the parameters of the waveguide, frequency. Due to the presence of air inside the housing and flexible acoustic isolation 14, 18, oscillations in a wide frequency band are not transmitted to the housing and are not emitted by it into the working medium, forming a stray field in the lateral and rear directions. In the receiving mode, an acoustic signal from the medium acts on the entire surface of the waveguide and the casing. Due to the air in the housing and the acoustic isolation 14, 18, only those vibrations are transmitted to the piezoelectric element 4, which are transmitted by a longitudinal normal wave traveling in the waveguide 1, excited by an acoustic signal incident on its side surface at an angle γ _max (ϖ). Directivity characteristics are the same in radiation-reception modes and have a low level of side and rear radiation. The shape of the directivity characteristic is determined by the acoustic and geometric parameters of the waveguide, the frequency. Experimental testing of the proposed waveguide directional transducer was carried out on mock-ups made in accordance with the proposed design, presented in figure 1.

, где с_φ(

(фиг.3, кривая 1). Там же отмечается линейный с увеличением частоты рост коэффициента радиационного затухания волны k₂ (фиг.4), что автоматически обеспечивает постоянство волнового размера излучающей поверхности и одинаковую ширину диаграммы направленности в полосе частот около октавы [5], что подтверждают и данные фиг.5б. Кроме того, направленность заявляемого устройства улучшена благодаря применению специальной конструкции узла крепления пьезопакета к волноводу, обеспечивающей акустическую развязку активного элемента и излучающей волноводной структуры от корпуса, и, как следствие, снижение уровня паразитного бокового излучения. Благодаря меньшим массогабаритным параметрам волновода, изготовленного из композитного материала, заявляемый преобразователь имеет меньшее лобовое сопротивление при буксировке и может использоваться при разработке буксируемых антенн, в том числе и низкочастотного диапазона (1,5-2) кГц.Figure 5 shows the radiation patterns of a waveguide transducer with various waveguides: 5a - a waveguide made of ebonite; 5b - waveguide made of ebonite - brass composite material. As the data show, when replacing ebonite with composite orthotropic finely layered ebonite - brass material, there is a significant improvement in the directional characteristics of the hydroacoustic antenna, namely: narrowing of the main lobe from 45 to 22º with a low level of side lobes -20 dB; there is an increase in sensitivity in radiation modes from 110 Pa · m / V to 240 Pa · m / V and reception from 4500 μV / Pa to 9950 μV / Pa. The operational efficiency of sonar systems using the inventive transducers can be significantly increased by increasing the concentration of acoustic energy in a more limited solid angle, since the axial concentration coefficient in comparison with the prototype increases from (16-18) to (70-75). It should be noted that due to the fact that the active element 4, located in a robust housing 3, is isolated from hydrostatic pressure in the working medium by a solid-state waveguide 1, the design can be used at large depths of up to 5000 m, which is confirmed by tests in a high-pressure tank. The radiation pattern can remain constant in the frequency band around an octave, if you select a range of operating frequencies in the region of a weak dispersion of the phase velocity of a normal wave

, where with _φ (

(figure 3, curve 1). In the same place, a linear increase in the frequency of the radiation attenuation coefficient of the wave k ₂ is noted (Fig. 4), which automatically ensures a constant wave size of the radiating surface and the same radiation pattern width in the frequency band around an octave [5], which is also confirmed by the data of Fig. 5b. In addition, the directivity of the claimed device is improved due to the use of a special design of the attachment unit of the piezoelectric packet to the waveguide, which provides acoustic isolation of the active element and radiates the waveguide structure from the housing, and, as a result, reduces the level of spurious side radiation. Due to the smaller weight and size parameters of the waveguide made of composite material, the inventive converter has lower drag when towing and can be used in the development of towed antennas, including the low-frequency range (1.5-2) kHz.

Thus, the claimed hydroacoustic directional waveguide transducer ensures the achievement of narrower radiation patterns with a lower level of side lobes, high radiated power, sensitivity, both in the radiation and reception modes, increasing the strength and reliability of its design, along with lower weight and size characteristics of the waveguide, the ability work in the frequency band. In addition to the above, it is also worth noting other advantages of the emitter, which are manifested during its operation - the ability to work at great depths, as well as in towing mode, which makes it promising for use in sonar telemetry, communication, sonar, and seabed profiling systems, in dynamic schemes tomography, including as antennas of broadband signals. The effectiveness of the functioning of these systems can be significantly increased when using the inventive converter by increasing the concentration of acoustic energy in a more limited solid angle.

Information sources

1. Sverdlin G.M. Hydroacoustic transducers and antennas. - L .: Shipbuilding, 1980, p. 172, Fig. 6.11.

2. Church D.R.A., A New Type Directive Sound Sourse for Long Range Sonar., IRE Wescon Convention Record, 1959, Pt. 6, p. 4-12.

3. Charch. A new type of directional sound source for early warning sonars // Foreign Radio Electronics. - 1960. No. 3. - p. 81-87.

4. Stepanov B.G. Hydroacoustic transducer waveguide type US Pat. RU 2393644, H04R 1/44, H04R 1/00, op. 06/27/2010.

5. Maltsev Yu.V., Prokopchik S.E. Hydroacoustic waveguide antennas and the prospects for their use in technical means of ocean research // Underwater research and robotics. 2010. No2 (10). S.51-71, Fig. 9, 17, 26.

6. Rytov S.M. Acoustic properties of a finely layered medium. Ak. Well, vol. II, issue 1, p. 71-83.

7. Bataev A.A., Bataev V.A. Composite materials. M .: Logos, 2006, 398 p.

Claims (2)

1. Hydroacoustic waveguide directional transducer containing a gas-filled strong housing isolated from the external environment, in which an active element is placed in the form of a reinforced bag consisting of a set of piezoceramic washers with polarization in height, rigidly docked with an elastic cylindrical waveguide through a glass-shaped fixing-sealing pad , its connection with the robust housing is flexible, characterized in that the waveguide is made of composite material, for example, ebonite and brass, and edstavlyaet a periodic small-layered structure consisting of identical recurring units of equal thickness h = h ₁ + h ₂ where h ₁ and h ₂ - uniform layer thickness of the materials from which the composite member, with the relative thickness of the metal layer $${\tilde{h}}_2=(0.1-0.15)$$

where $${\tilde{h}}_2=h_2/(h_{\mathrm{one}}+h_2)$$

; the orientation of the links of the composite material is perpendicular to the axis of the waveguide, and the waveguide is reinforced with thin elastic rods. 2. The hydroacoustic waveguide directional transducer according to claim 1, characterized in that the thin elastic rods with which the waveguide is reinforced are made of titanium.

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