CN101949732A - Resonant cavity type hydrophone for deepwater soundwave detection - Google Patents

Abstract

The invention discloses a resonant cavity type hydrophone for deepwater soundwave detection. The hydrophone is characterized in that an anti-pressure medium soundwave resonant cavity comprises an air cavity and a water cavity; the length of the air cavity is half the soundwave operating wavelength lambda; the inner diameters of the two cavities are equal; and the receiving surface of the hydrophone is placed in the water cavity and faces the air cavity. The hydrophone can still realize detection of the soundwave signals even under high pressure in deepwater and, with such a simple structure, can not only maintain the high measuring sensitivity of the traditional hydrophones under normal pressure but also overcome the defect that the traditional hydrophones can not detect the soundwave signals in water under high pressure in deepwater. The equipment is simple in design, has small volume and low cost and is convenient to use. The hydrophone can be widely applied to deepwater pipelines, oil wells, deep sea and other soundwave detection systems under high pressure.

Description

The resonant cavity type nautical receiving set that is used for detecting deep water sound waves

Technical field

The present invention relates to nautical receiving set under water, particularly relate to a kind of resonant cavity type nautical receiving set that is used for detecting deep water sound waves.

Background technology

Along with development of human society, wireless communication technology is being played the part of more and more important effect in our life.Traditional electromagnetic wave radio communication is only to be familiar with to everybody again, as the radio station of widespread use in the mobile phone that uses in the life, the military affairs etc. all transmitting information by electromagnetic wave.But the communication mode that electromagnetic in some cases radio communication is but not necessarily best is such as the radio communication in the deep water.

Because seawater is to the attenuation of Electromagnetic effect, underwater communication is difficulty very.So, can utilize sound wave to transmit information? in the past few years, the various countries scientist is devoted to the research of seabed sound wave communication always, promptly the form of the data that contain sound, text and image in a large number with sound wave is transmitted in the seabed.At present, utilization to sound in the military affairs mainly concentrates on use sonar detection, scouting and simple and easy communication aspects, differentiate its orientation as the sound that sends according to enemy's submarine in the water, utilize active sonar search submarine mine, utilize depth-determining sonar to determine seabed depth, discern enemy and we etc. according to the signal that sonar sends and regains.In the commodity production, also there are a lot of places need use sound wave.Such as the deep water communication of mine, oil well class, how to transmit signals to mine or oil well bottom to control certain System Operation.

Though the sound wave communication technology makes a breakthrough, also there are many difficult problems to wait to capture.At first, sound wave also can weaken in transport process gradually, makes signal weaker.Simultaneously, because water is a fabulous transmission medium to sound, various sound waves can both transmit hundreds and thousands of kms, and the people is difficult to making a distinction with the sound wave of data and common background noise.

And very perfect acoustic sounding instrument do not appear in the underwater communication at present, can be normal under the condition of thousands of meters depths UHV (ultra-high voltage), stable, and work with sensitivity.Though traditional nautical receiving set can be worked under water, be used for the detecting underwater acoustic ripple, and higher sensitivity arranged, but traditional nautical receiving set is operated in 500 meters with interior shallow water area more, under the condition of high voltage of deep water, even through particular design, its sensitivity also has largely and worsens, and its bearing structure also is difficult to long-term stable operation.Therefore, press for a kind of novel sonic detector and make it under deep water, to work, and very high detection sensitivity will be arranged.

Summary of the invention

The object of the present invention is to provide a kind of resonant cavity type nautical receiving set that is used for detecting deep water sound waves, utilize the sound wave resonance effect to realize the energy accumulation of sound wave, make the sound wave in the deep water be coupled in the resonator cavity, thereby and the accumulation that realizes energy make traditional nautical receiving set be placed on promptly not need to bear very high hydraulic pressure in the water-filled resonator cavity of sealing and can in resonator cavity, detect the sound wave that coupling is come in the deep water of outside simultaneously again.

The technical solution adopted for the present invention to solve the technical problems is:

Withstand voltage medium acoustic wave resonator of the present invention comprises air chamber and two cavitys of water cavity, and the length of air chamber is that the internal diameter of 1/2nd, two cavitys of sound wave operation wavelength λ equates, the receiving plane of nautical receiving set is placed on the water cavity the inside, towards the air chamber direction.

Air chamber in the described withstand voltage medium acoustic wave resonator is right cylinder or rectangular body cavity, closed at both ends, and the water cavity in the described withstand voltage medium acoustic wave resonator is right cylinder or a rectangular body cavity of filling water.

The present invention compares the beneficial effect that has with background technology:

Even the present invention is of value to the detection that still can realize acoustic signals in the deep water high-pressure situations, and realized surveying acoustic signals under the deep water high pressure with traditional nautical receiving set by this simple structure.It has overcome traditional nautical receiving set can not be surveyed acoustic signals under the deep water high pressure shortcoming, and a kind of acoustic sounding equipment of high stability is provided.This device design is simple, and volume is little, and is with low cost and easy to use, overcome the deficiency of traditional nautical receiving set fully.

The present invention can be widely used in deep underwater pipes, oil well, the contour resonant cavity type nautical receiving set of depressing the acoustic sounding system in deep-sea.

Description of drawings

Fig. 1 is that sound wave reflects in multilayered medium, the transmission synoptic diagram.

Fig. 2 is a resonant cavity type hydrophone structure synoptic diagram.

Among the figure: 1. withstand voltage medium acoustic wave resonator, 2. air chamber, 3. water cavity, 4. nautical receiving set, 5. deep underwater pipes, the 6. water in the deep underwater pipes.

Embodiment

The invention will be further described below in conjunction with drawings and Examples.

Reflection and transmission can take place in sound wave in multilayered medium, particularly when sound wave impinges perpendicularly on multilayer planar, we can write out acoustic pressure p (x) and vibration velocity v (x) in each layer medium with wave equation and You La equation, as shown in Figure 1:

Wherein the 3rd layer of medium is identical with the ground floor medium, identical density is promptly arranged, the identical velocity of sound.The thickness of middle layer medium is l, and sound wave is from left side ground floor incident.p _1i(x) expression ground floor incident wave, p _1r(x) expression ground floor reflection wave, ρ ₁And c ₁Represent the ground floor density of medium and the velocity of sound respectively, p _2i(x) expression second layer incident wave, p _2r(x) expression second layer reflection wave, ρ ₂And c ₂Represent the second layer density of medium and the velocity of sound respectively, p _3i(x) the 3rd layer of transmitted wave of expression, ρ ₁And c ₁Represent the 3rd layer of density of medium and the velocity of sound respectively.

We can represent their acoustic pressure p (x) and vibration velocity v (x), the acoustic pressure p in the ground floor medium successively in three layers of medium ₁(x) and vibration velocity u ₁(x) be expressed as:

$p_1\left(x\right)=A_1{e}^{-j{k}_{1}x}+B_1{e}^{j{k}_{1}x}$ (1)

$u_1\left(x\right)=\frac{1}{Z_1}(A_1{e}^{-j{k}_{1}x}-B_1{e}^{j{k}_{1}x}),({\mathrm{<figure-callout\; id="1"\; label="Z"\; filenames="HSA00000230326000012.png"\; state="\{\{state\}\}">Z</figure-callout>}}_1={\mathrm{\&rho;}}_1{c}_1)$

A wherein ₁The amplitude of the acoustic pressure of expression ground floor incident acoustic wave, B ₁Be the amplitude of the acoustic pressure of ground floor reflective sound wave, The sound wave formula of propagating towards the x positive dirction in the expression ground floor medium,

The sound wave formula of propagating towards the x negative direction in the expression ground floor medium, k ₁Be the wave vector in the ground floor medium.

Acoustic pressure p in the second layer medium ₂(x) and vibration velocity u ₂(x) be expressed as:

$p_2\left(x\right)=A_2{e}^{-j{k}_{2}x}+B_2{e}^{j{k}_{2}x}$ (2)

$u_2\left(x\right)=\frac{1}{Z_2}(A_2{e}^{-j{k}_{2}x}-B_1{e}^{j{k}_{2}x}),({\mathrm{<figure-callout\; id="2"\; label="Z"\; filenames="HSA00000230326000012.png"\; state="\{\{state\}\}">Z</figure-callout>}}_2={\mathrm{\&rho;}}_2{c}_2)$

A wherein ₂The amplitude of the acoustic pressure of expression second layer incident acoustic wave, B ₂Be the amplitude of the acoustic pressure of second layer reflective sound wave,

The sound wave formula of propagating towards the x positive dirction in the expression second layer medium,

The sound wave formula of propagating towards the x negative direction in the expression second layer medium, k ₂Be the wave vector in the second layer medium.

Acoustic pressure p in the 3rd layer of medium ₃(x) and vibration velocity u ₃(x) be:

$p_3\left(x\right)=A_3{e}^{-j{k}_3(x-l)}$ (3)

$u_3\left(x\right)=\frac{1}{Z_1}{e}^{-j{k}_3(x-l)}$

A wherein ₃The amplitude of representing the acoustic pressure of the 3rd layer of incident acoustic wave,

Represent in the 3rd layer of medium sound wave formula propagated towards the x positive dirction, k ₃Be the 3rd layer of wave vector in the medium.

Sound wave is propagated the continuity that will satisfy boundary acoustic pressure and vibration velocity in these three layers of media, can know and satisfy following equation:

p ₁(x)| _x＝0＝p ₂(x)| _x＝0 p ₂(x)| _x＝l＝p ₃(x)| _x＝l

(4)

u ₁(x)| _x＝0＝u ₂(x)| _x＝0 u ₂(x)| _x＝l＝u ₃(x)| _x＝l

Can solve top four formula simultaneous solutions when second layer medium and to satisfy k ₂During l=n π, the amplitude maximum of second layer medium the inside standing wave, the transmissivity that this moment, sound wave was transmitted to the 3rd layer of medium from the ground floor medium also maximum just equals 1.While sound wave resonance on the medium of middle layer.Obtain:

$\begin{array}{cc}{A}_2=\frac{A_1(1+\frac{Z_2}{Z_1})}{2}& {\mathrm{<figure-callout\; id="2"\; label="B"\; filenames="HSA00000230326000012.png"\; state="\{\{state\}\}">B</figure-callout>}}_2=\frac{A_1(1-\frac{Z_2}{Z_1})}{2}\end{array}---\left(5\right)$

Can find that when resonance sound wave in the maximum sound pressure of second layer medium is | A ₂|+| B ₂|, therefore, if ground floor and the 3rd layer of medium are set at water, and middle that layer medium is assumed to air, and then the length when air layer satisfies above-mentioned k ₂During l=n π, the sound wave that is in the middle air layer of water layer can produce resonance, makes that the energy product fusion of the inside is big.

According to the character of above-mentioned sound wave resonance, in order to measure the sound wave in the deep water, made an air acoustic wave resonator, realize the measurement of acoustic signals by resonance effect.For the course of work of resonant cavity type nautical receiving set is described, for an example of in deep underwater pipes, surveying acoustic signals.In the deep underwater pipes 5 of vertically placing, place a withstand voltage medium acoustic wave resonator 1 as Fig. 2,, can bear the high pressure in the deep water like this such as the steel acoustic wave resonator.The length of the air chamber 2 in resonator cavity just is a half of sound wave operation wavelength, because coupling effect, the acoustic signals in the water 6 in the deep underwater pipes will be coupled to 2 li of air chambers, and the acoustic pressure that inside gathers strength inside making becomes big.A water cavity 3 in like manner is set in an end of withstand voltage medium acoustic wave resonator 1, and the length of water cavity 3 there is not requirement, can place nautical receiving set and get final product, and thickness can appropriate change, can guarantee under the high voltage bearing condition Bao Yuehao more.In water cavity 3, place a traditional nautical receiving set 4.This nautical receiving set 4 is coupled to the acoustic signals in the water cavity 3 in can admission of air chamber 2, when withstand voltage medium acoustic wave resonator 1 is coupled to air chamber 2 to the acoustic signals in the deep underwater pipes, be coupled to water cavity 3 again, traditional nautical receiving set 4 can be measured this signal, do not need to bear the high pressure of deep water again, so just realized the detection of acoustic signals under the deep water high pressure, it is similar to survey the sound wave principle in other deep water.

Frequency of operation of the present invention is uncertain, can determine earlier that the sound wave operation wavelength sets the size of air chamber in the corresponding withstand voltage medium acoustic wave resonator again, and the size of water cavity does not require.Same withstand voltage medium acoustic wave resonator can be operated in a plurality of frequencies simultaneously, so long as the sound wave of the integral multiple of fundamental frequency, thereby can in the water cavity of back, receive by the air chamber resonance in resonator cavity, so its working frequency range has discreteness with traditional nautical receiving set.

The above, it only is the preferred embodiments of in deep underwater pipes, surveying of the present invention, be not that the present invention is done any pro forma qualification, any those skilled in the art may utilize the technology contents of above-mentioned announcement to be changed or be modified to the equivalent example of equivalent variations, but every technical solution of the present invention content that do not break away from, any simple modification, equivalent variations and modification according to technical spirit of the present invention is done above example all still belong in the scope of technical solution of the present invention.

Claims (2)

1. resonant cavity type nautical receiving set that is used for detecting deep water sound waves, it is characterized in that: withstand voltage medium acoustic wave resonator (1) comprises air chamber (2) and (3) two cavitys of water cavity, the length of air chamber (2) is 1/2nd of sound wave operation wavelength λ, the internal diameter of two cavitys equates, the receiving plane of nautical receiving set (4) is placed on the water cavity the inside, towards air chamber (2) direction.

2. a kind of resonant cavity type nautical receiving set that is used for detecting deep water sound waves according to claim 1, it is characterized in that: the air chamber (2) in the described withstand voltage medium acoustic wave resonator (1) is right cylinder or rectangular body cavity, water cavity (3) in the closed at both ends, described withstand voltage medium acoustic wave resonator (1) is for filling the right cylinder or the rectangular body cavity of water.

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