CN102914354A - Three-dimensional combined hydrophone - Google Patents

Abstract

The invention relates to the field of hydrophones, in particular to a three-dimensional combined hydrophone with the capacity of carrying out synchronous concurrent measurement on a sound pressure, a particle vibration velocity and a vibration velocity first-order space partial derivative. The three-dimensional combined hydrophone comprises two-dimensional vector hydrophones, a sound pressure hydrophone and a rigid frame, wherein the two-dimensional vector hydrophones are suspended at the center of the rigid frame, the sound pressure hydrophone is fixed at the center of the rigid frame, and the vector hydrophones are arranged on two sides of the sound pressure hydrophone in a pairwise symmetry manner. The sound pressure, the particle vibration velocity and the vibration velocity first-order space partial derivative in an underwater plane wave sound field can be completely measured by using six two-dimensional vector hydrophones and one sound pressure hydrophone, and all components of the sound pressure, the particle vibration velocity and the vibration velocity first-order space partial derivative can be completely measured, thus the three-dimensional combined hydrophone has a simple structure and is more accurate in directivity.

Description

The box-like nautical receiving set of a kind of three-dimensional group

Technical field

The present invention relates to the nautical receiving set field, be specifically related to a kind of box-like high directivity nautical receiving set of three-dimensional group that synchronous concurrent is measured acoustic pressure, particle vibration velocity and vibration velocity single order space partial derivative ability that has.

Background technology

The high directivity nautical receiving set is the sensor that a kind of synchronously concurrent is measured acoustic pressure (one-component), particle vibration velocity (three components) and vibration velocity space single order partial derivative (nine components) in the harmonious plane wave sound field under water, displacement and the acceleration isovector of the vibration velocity of water particle and water particle acoustic pressure gradient, vibration can convert mutually, and the vibration velocity space single order partial derivative of water particle then can be changed mutually with dyads such as water particle acoustic pressure space second-order partial differential coefficient, vibration displacement space single order partial derivative and acceleration space single order partial derivatives.The nautical receiving set that the high directivity nautical receiving set is compared other types has more sharp-pointed directive property and the directional gain of Geng Gao, its combination directivity pattern (the normalization directive property of acoustic pressure, particle vibration velocity and the single order partial derivative weighted sum of vibration velocity space)-the I of 3dB beam angle reaches 65 °, directional gain 9.5dB, and the combination directivity pattern of the vector hydrophone of at present widespread use-3dB beam angle minimum can only reach 104 °, directional gain 6dB.Therefore, the high directivity nautical receiving set has very wide application prospect in the fields such as detecting and locating of target.

Have at present and publish about patent and the document of high directivity nautical receiving set on a small quantity, the nautical receiving set that this class has high directivity has adopted numerous sensor in order to reach the purpose of measuring vibration velocity space single order partial derivative, cause hydrophone structure complicated, poor reliability, although the high directivity nautical receiving set that has simplifies the structure, can't the perfect measurement acoustic pressure, whole components of particle vibration velocity and vibration velocity space single order partial derivative.Therefore, the present invention has designed and produced a kind of simple in structure, and concurrent is measured the box-like high directivity nautical receiving set of three-dimensional group of whole components of acoustic pressure, particle vibration velocity and vibration velocity space single order partial derivative in the harmonious plane wave sound field under water synchronously.

Summary of the invention

The object of the present invention is to provide the more box-like nautical receiving set of three-dimensional group of sharpening of a kind of simple in structure, directive property.

The object of the present invention is achieved like this:

The box-like nautical receiving set of three-dimensional group, comprise two-dimensional vector hydrophone, pressure hydrophone, rigid frame, two-dimensional vector hydrophone hangs on the center of rigid frame, and pressure hydrophone is fixed in the center of rigid frame, and vector hydrophone is symmetrically distributed in the both sides of pressure hydrophone in twos.

Two-dimensional vector hydrophone is 6, and pressure hydrophone is 1, and pressure hydrophone is positioned at the rectangular coordinate system origin position, and two-dimensional vector hydrophone is symmetrically distributed in respectively on the x-axis, y-axis and z-axis of initial point both sides in twos.

Two-dimensional vector hydrophone equates to the distance of pressure hydrophone.

The distance of homoaxial two-dimensional vector hydrophone is less than wave length of sound.

Two-dimensional vector hydrophone, pressure hydrophone are fixed into the box-like nautical receiving set of three-dimensional group by the rigid frame assembling.

Rigid frame is made by stainless steel material.

Beneficial effect of the present invention is:

The present invention only utilize six two-dimensional vector hydrophones and pressure hydrophone just can perfect measurement acoustic pressure, particle vibration velocity and the vibration velocity space single order partial derivative in the plane wave sound field under water, can the perfect measurement acoustic pressure, whole components of particle vibration velocity and vibration velocity space single order partial derivative, simple in structure, directive property is sharpening more.

Description of drawings

Fig. 1 is the box-like nautical receiving set sensitive element of three-dimensional group spatial distribution map;

Fig. 2 is the vector hydrophone structural representation;

Fig. 3 is that pressure hydrophone is fixed in rigid frame structure figure;

Fig. 4 is the box-like nautical receiving set space structure of three-dimensional group figure;

Fig. 5 is plane wave directivity synoptic diagram;

Fig. 6 is the box-like hydrophone directivity figure of three-dimensional group.

Embodiment

Below in conjunction with accompanying drawing the present invention is described further.

For complete acquisition sound field information such as acoustic pressure, particle vibration velocity and vibration velocity space single order partial derivative in the harmonious plane wave sound field under water, the present invention proposes the box-like nautical receiving set of a kind of three-dimensional group, combined by six two-dimensional vector hydrophones and a pressure hydrophone.Vector hydrophone 1, vector hydrophone 2 are symmetrically distributed in the both sides of x axial coordinate initial point, and sensitive axes is to being x, z axle; Vector hydrophone 3, vector hydrophone 4 are symmetrically distributed in the both sides of y axial coordinate initial point, and sensitive axes is to being x, y axle; Vector hydrophone 5, vector hydrophone 6 are symmetrically distributed in the both sides of z axial coordinate initial point, and sensitive axes is to being y, z axle, and each two vector hydrophone spacing on axially is L, in order to guarantee measuring accuracy, should satisfy L＜＜λ, λ is wave length of sound; Pressure hydrophone 7 places the true origin of rectangular coordinate system, such as accompanying drawing 1.

The box-like nautical receiving set of three-dimensional group also has following features:

(1) vector hydrophone and pressure hydrophone 7 are positioned at the geometric center of rigid frame 12;

(2) sensitive axes of vector hydrophone to symmetrical hook 10 at same plane;

(3) the vector hydrophone sensitive axes on the different coordinate axis is to the place planar quadrature;

(4) seven rigid frames 12 can be assembled as required.

In actual measurement, with reference to the accompanying drawings 1, the acoustic pressure p at O place, the box-like nautical receiving set of three-dimensional group center is recorded by pressure hydrophone 7, three vibration velocity component (u _x, u _y, u _z) being averaged by each two vector hydrophone measurement on axially obtains nine vibration velocity space single order partial derivative components

Two vector hydrophones on axial by each obtain approximate value through finite differences.

The combination directivity function of the acoustic pressure of the box-like nautical receiving set of three-dimensional group, particle vibration velocity and vibration velocity space single order partial derivative can be expressed as

W wherein _p, w _x, w _y, w _z, w _Xx, w _Yy, w _Zz, w _Xy, w _Xz, w _YzBe any weighting coefficient,

As shown in Figure 5, θ be incident plane wave at the angle of rectangular coordinate system xoy plane and x axle, be called horizontal azimuth,

Angle for incident plane wave and rectangular coordinate system z axle is called the angle of pitch.A, b, c are respectively three vibration velocity component u _x, u _y, u _zThe normalization directivity function, a ², b ², c ²Be respectively

The normalization directivity function, ab is With

The normalization directivity function, ac is

With

The normalization directivity function, bc is

With

The normalization directivity function.The directional gain of the box-like nautical receiving set of three-dimensional group can be expressed as

Wherein, θ ₀Be the angle of directive property maximum value direction at rectangular coordinate system xoy plane and x axle,

Be the angle of directive property maximum value direction and rectangular coordinate system z axle, therefore

Be called normalization combination directivity function.Will have influence on shape and the directional gain of directivity pattern to the different values of weighting coefficient, weighing nautical receiving set performance a kind of directivity pattern commonly used is the directivity pattern that is called " maximum sensitivity index ", as weighting coefficient w _p=1, w _x=-2a ₀, w _y=-2b ₀, w _z=-2c ₀,

w _Xy=-10a ₀b ₀, w _Xz=-10a ₀c ₀, w _Yz=-10b ₀c ₀,

Make θ 0=0 °,

Be that directivity pattern principal maximum direction is pointed to rectangular coordinate system x axle positive dirction, then can obtain the directivity pattern of the box-like nautical receiving set of three-dimensional group " maximum sensitivity index ", as shown in Figure 6,65 ° of directivity pattern main lobes-3dB beam angle, directional gain DI=9.5dB, directivity pattern can be by adjusting θ ₀With

The principal maximum direction is aimed at any locus, and directional gain and directivity pattern shape all do not change.

As shown in Figure 2, the sensitive axes of two-dimensional vector hydrophone to symmetrical four hooks 8 at same plane.Pressure hydrophone 7 is fixed in the center of rigid frame 12 by web member 10, as shown in Figure 3.Vector hydrophone is hung on the center of rigid frame 12 with flexible material 13, and flexible material 13 embeds in the grooves 11, avoids sliding at framework, and the sensitive axes of noting vector hydrophone in the suspension process is to corresponding with Fig. 1, and hang is corresponding with Fig. 4.Every crossbeam of rigid frame 12 has pilot hole 9, will assemble as shown in Figure 4 with the rigid frame 12 of vector hydrophone and pressure hydrophone, and the box-like nautical receiving set 14 of three-dimensional group is namely assembled and finished.

For a more detailed description below in conjunction with the method that 1 couple of the present invention of accompanying drawing measures sound field:

The box-like nautical receiving set of three-dimensional group synchronously concurrent is measured acoustic pressure, particle vibration velocity and vibration velocity single order space partial derivative in the sound field under water.Utilize pressure hydrophone 7 can directly measure the acoustic pressure amount p at O place, the box-like nautical receiving set of three-dimensional group center, three components of particle vibration velocity u can utilize averaging method to measure by vector hydrophone 1-6:

$u_x=\frac{u_{1x}+u_{2x}}{2}$

$u_y=\frac{u_{3y}+u_{4y}}{2}---\left(3\right)$

$u_z=\frac{u_{5z}+u_{6z}}{2}$

Wherein, u _1xBe the particle vibration velocity x axial component that vector hydrophone 1 records, u _2xBe the particle vibration velocity x axial component that vector hydrophone 2 records, u _3yBe the particle vibration velocity y axial component that vector hydrophone 3 records, u _4yBe the particle vibration velocity y axial component that vector hydrophone 4 records, u _5zBe the particle vibration velocity z axial component that vector hydrophone 5 records, u _6zThe particle vibration velocity z axial component that records for vector hydrophone 6.According to the equation of motion of small amplitude wave in the perfect medium, suppose that sound wave is harmonious plane wave, then has

-jωρ ₀u=▽p (4)

ρ wherein ₀Static Density when not having disturbance in the medium,

Angular frequency=2 π f, f is the frequency of sound wave in the medium, by following formula as seen, the particle vibration velocity that obtains medium can obtain acoustic pressure gradient.Continuation is asked single order space partial derivative to the right and left of following formula, then has

$-j{\mathrm{\&omega;\&rho;}}_0\left[\begin{array}{ccc}\frac{\&PartialD;u_x}{\&PartialD;x}& \frac{\&PartialD;u_x}{\&PartialD;y}& \frac{\&PartialD;u_x}{\&PartialD;z}\\ \frac{\&PartialD;u_y}{\&PartialD;x}& \frac{\&PartialD;u_y}{\&PartialD;y}& \frac{\&PartialD;u_y}{\&PartialD;z}\\ \frac{\&PartialD;u_z}{\&PartialD;x}& \frac{\&PartialD;u_z}{\&PartialD;y}& \frac{\&PartialD;u_z}{\&PartialD;z}\end{array}\right]=\left[\begin{array}{ccc}\frac{{\&PartialD;}^{2}p}{\&PartialD;x^2}& \frac{\&PartialD;}{\&PartialD;y}\frac{\&PartialD;p}{\&PartialD;x}& \frac{\&PartialD;}{\&PartialD;z}\frac{\&PartialD;p}{\&PartialD;x}\\ \frac{\&PartialD;}{\&PartialD;x}\frac{\&PartialD;p}{\&PartialD;y}& \frac{{\&PartialD;}^{2}p}{\&PartialD;{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA00002312140000011.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}& \frac{\&PartialD;}{\&PartialD;z}\frac{\&PartialD;p}{\&PartialD;y}\\ \frac{\&PartialD;}{\&PartialD;x}\frac{\&PartialD;p}{\&PartialD;z}& \frac{\&PartialD;}{\&PartialD;y}\frac{\&PartialD;p}{\&PartialD;z}& \frac{{\&PartialD;}^{2}p}{\&PartialD;z^2}\end{array}\right]---\left(5\right)$

Therefore, the vibration velocity space single order partial derivative that obtains medium can obtain acoustic pressure space second-order partial differential coefficient.Because in the plane wave sound field, the curl of particle vibration velocity is 0, therefore

$\frac{\&PartialD;u_x}{\&PartialD;y}=\frac{\&PartialD;u_y}{\&PartialD;x},$ $\frac{\&PartialD;u_x}{\&PartialD;z}=\frac{\&PartialD;u_x}{\&PartialD;x},$ $\frac{\&PartialD;u_y}{\&PartialD;z}=\frac{\&PartialD;u_z}{\&PartialD;y}---\left(6\right)$

The measurement of vibration velocity space single order partial derivative is utilized the method for finite-difference approximation partial differential:

$\frac{\&PartialD;u_x}{\&PartialD;x}\&cong;\frac{u_{1x}-u_{2x}}{L},$ $\frac{\&PartialD;u_y}{\&PartialD;y}\&cong;\frac{u_{3y}-u_{4y}}{L},$ $\frac{\&PartialD;u_z}{\&PartialD;z}\&cong;\frac{u_{5z}-u_{6z}}{L}$

$\frac{\&PartialD;u_z}{\&PartialD;x}=\frac{\&PartialD;u_x}{\&PartialD;z}\&cong;\frac{u_{1z}-u_{2z}}{L},$ $\frac{\&PartialD;u_x}{\&PartialD;y}=\frac{\&PartialD;u_y}{\&PartialD;x}\&cong;\frac{u_{3x}-u_{4x}}{L},$ $\frac{\&PartialD;u_y}{\&PartialD;z}=\frac{\&PartialD;u_z}{\&PartialD;y}\&cong;\frac{u_{5y}-u_{6y}}{L}---\left(7\right)$

Wherein, u _1z, u _2zBe the particle vibration velocity z axial component that vector hydrophone 1, vector hydrophone 2 record, u _3x, u _4xBe the particle vibration velocity x axial component that vector hydrophone 3, vector hydrophone 4 record, u _5y, u _6yThe particle vibration velocity y axial component that records for vector hydrophone 5, vector hydrophone 6.According to the continuity equation in the little amplitude sound field of desirable quiescent atmosphere, suppose that sound field is harmonious, then has

$\frac{{\mathrm{\&rho;}}_1}{{\mathrm{\&rho;}}_0}=\frac{j}{\mathrm{\&omega;}}\{\frac{\&PartialD;u_x}{\&PartialD;x}+\frac{\&PartialD;u_y}{\&PartialD;y}+\frac{\&PartialD;u_z}{\&PartialD;z}\}---\left(8\right)$

ρ wherein ₀Static Density when not having disturbance in the medium, ρ ₁For sound wave by the time Media density this variable, according to the relative variation of Principles of Acoustics to Media density, the i.e. definition of decrement s:

$s=\frac{{\mathrm{\&rho;}}_1}{{\mathrm{\&rho;}}_0}---\left(9\right)$

Therefore, decrement s can be expressed as

$s=\frac{j}{\mathrm{\&omega;}}\{\frac{\&PartialD;u_x}{\&PartialD;x}+\frac{\&PartialD;u_y}{\&PartialD;y}+\frac{\&PartialD;u_z}{\&PartialD;z}\}---\left(10\right)$ 。

Claims (6)

1. box-like nautical receiving set of three-dimensional group, comprise two-dimensional vector hydrophone, pressure hydrophone, rigid frame, it is characterized in that: two-dimensional vector hydrophone hangs on the center of rigid frame, pressure hydrophone is fixed in the center of rigid frame, and vector hydrophone is symmetrically distributed in the both sides of pressure hydrophone in twos.

2. the box-like nautical receiving set of a kind of three-dimensional group according to claim 1, it is characterized in that: described two-dimensional vector hydrophone is 6, pressure hydrophone is 1, pressure hydrophone is positioned at the rectangular coordinate system origin position, and two-dimensional vector hydrophone is symmetrically distributed in respectively on the x-axis, y-axis and z-axis of initial point both sides in twos.

3. the box-like nautical receiving set of a kind of three-dimensional group according to claim 1 and 2 is characterized in that: described two-dimensional vector hydrophone equates to the distance of pressure hydrophone.

4. the box-like nautical receiving set of a kind of three-dimensional group according to claim 1 and 2, it is characterized in that: the distance of described homoaxial two-dimensional vector hydrophone is less than wave length of sound.

5. the box-like nautical receiving set of a kind of three-dimensional group according to claim 1 and 2 is characterized in that: described two-dimensional vector hydrophone, pressure hydrophone are fixed into the box-like nautical receiving set of three-dimensional group by the rigid frame assembling.

6. the box-like nautical receiving set of a kind of three-dimensional group according to claim 1 and 2, it is characterized in that: described rigid frame is made by stainless steel material.

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