阅读说明：本技术 一种测量浅海中海洋管道声散射强度的装置及方法 (Device and method for measuring sound scattering intensity of pipeline in shallow sea ) 是由 刘永伟 周志豪 王璐 周文林 冯宝铭 王思贤 郑朋辉 董皓辰 商德江 于 2021-06-24 设计创作，主要内容包括：本发明提供一种测量浅海中海洋管道声散射强度的装置及方法,包括发射换能器、圆柱架、第一水听器、异形支架、第二水听器,发射换能器位于圆柱架的中心,第一水听器位于圆柱架的外侧,异形支架放置在海洋管道表面,第二水听器放置在异形支架的外侧；一种测量浅海中海洋管道声散射强度的装置,还包括方法；该测量浅海中海洋管道声散射强度的装置及方法减少了海洋管道声散射信号中来自海面和海底混响的影响,削弱了洋流的大涡团脉动所带来的低频干扰,适合在浅海等洋流环境中进行海洋管道声散射强度的测量,避免了指向性换能器声波束聚焦及对准等问题,具有较好的工程应用前景。(The invention provides a device and a method for measuring sound scattering intensity of a marine pipeline in shallow sea, wherein the device comprises a transmitting transducer, a cylindrical frame, a first hydrophone, a special-shaped support and a second hydrophone, the transmitting transducer is positioned in the center of the cylindrical frame, the first hydrophone is positioned on the outer side of the cylindrical frame, the special-shaped support is placed on the surface of the marine pipeline, and the second hydrophone is placed on the outer side of the special-shaped support; an apparatus for measuring the acoustic scattering intensity of a pipeline in the shallow sea, further comprising a method; the device and the method for measuring the sound scattering intensity of the marine pipeline in the shallow sea reduce the influence of reverberation from the sea surface and the sea bottom in the sound scattering signal of the marine pipeline, weaken low-frequency interference caused by the pulsation of a large vortex group of ocean current, are suitable for measuring the sound scattering intensity of the marine pipeline in the ocean current environments of the shallow sea and the like, avoid the problems of focusing and aligning of sound beams of a directional transducer and have good engineering application prospect.)

1. The utility model provides a measure device of shallow sea marine pipeline sound scattering intensity which characterized in that: the transmitting transducer is located in the center of the cylindrical frame, the first hydrophone is located on the outer side of the cylindrical frame, the special-shaped support is placed on the surface of an ocean pipeline, and the second hydrophone is placed on the outer side of the special-shaped support.

2. The apparatus for measuring the sound scattering intensity of a pipeline in the shallow sea according to claim 1, wherein: the cylindrical frame is a frame consisting of a top surface, side surfaces and a bottom surface, the top surface is made of concentric circles and supporting rods with different radiuses, the side surfaces are uniformly distributed straight rods, the bottom surface is made of concentric circles and supporting rods with different radiuses, a vertical rod is arranged in the cylindrical frame, the head of the vertical rod is a circular ring, and the transmitting transducer is positioned in the center of the cylindrical frame, namely the transmitting transducer is arranged on the circular ring; the top surface of the cylindrical frame is provided with a plurality of hollow spherical shells, the bottom surface of the cylindrical frame is provided with a plurality of sound-absorbing wedges, each straight rod on the side surface is evenly embedded with a first ceramic bearing, and the outer side of each first ceramic bearing is connected with a first flapping wing.

3. An apparatus for measuring the sound scattering intensity of a pipeline in the shallow sea according to claim 1 or 2, wherein: the special-shaped support comprises a plastic bearing, a cross rod, a vertical rod, a second ceramic bearing and a second flapping wing, the plastic bearing is embedded to the outer surface of the marine pipeline, the cross rod is embedded to the outer side of the plastic bearing, the end of the cross rod is connected with the middle of the vertical rod, the second ceramic bearing is uniformly arranged on the vertical rod, the second flapping wing is arranged on the second ceramic bearing, and the second hydrophone is placed on the outer side of the special-shaped support and is arranged at the lower end of the vertical rod.

4. The apparatus for measuring the sound scattering intensity of a pipeline in the shallow sea according to claim 3, wherein: the second hydrophone is at a distance of 0.5 times the outer diameter of the marine pipeline closest to the surface of the marine pipeline.

5. An apparatus for measuring the sound scattering intensity of a pipeline in the shallow sea according to claim 1 or 2, wherein: the transmitting transducer is an omnidirectional underwater sound transmitting transducer.

6. The apparatus for measuring the sound scattering intensity of a pipeline in the shallow sea according to claim 3, wherein: the transmitting transducer is an omnidirectional underwater sound transmitting transducer.

7. The apparatus for measuring the sound scattering intensity of a pipeline in the shallow sea according to claim 4, wherein: the transmitting transducer is an omnidirectional underwater sound transmitting transducer.

8. A method for measuring the sound scattering intensity of a pipeline in shallow sea comprises a device for measuring the sound scattering intensity of the pipeline in shallow sea, and is characterized in that: the method comprises the following steps:

the first step is as follows: the transmitting transducer transmits a single-frequency CW pulse signal, narrow-band filtering is carried out on the signal acquired by the first hydrophone, and then Fourier transform is carried out to obtain the CW pulse signal with the amplitude P₁Narrow-band filtering is carried out on the signal acquired by the second hydrophone, and then Fourier transform is carried out to obtain the amplitude P of the CW pulse signal₂；

The second step is that: according to the hairDistance L between the transmitting transducer and the first hydrophone₁Calculating the starting time of transmitting the CW pulse by the transmitting transducer according to the CW pulse signal acquired by the first hydrophone;

the third step: the CW pulse starting time determined by the second step is compared with the CW pulse starting time collected by the second hydrophone to determine the distance L between the transmitting transducer and the second hydrophone₂；

The fourth step: through L₁And L₂Comparing, calculating the direct wave amplitude P of CW pulse arriving in the second hydrophone according to the spherical wave expansion rule₃；

The fifth step: according to the formulaAnd calculating the sound scattering intensity of the marine pipeline.

Technical Field

The invention relates to a device and a method for measuring the sound scattering intensity of a marine pipeline in shallow sea, belonging to the field of acoustic measurement.

Background

In the past, the research on the marine pipeline focuses on the aspects of wax precipitation state, corrosion resistance and the like, and the acoustic characteristics of the marine pipeline are rarely concerned. The underwater vehicle often approaches the marine pipeline to explore the surface state of the pipeline and needs to accurately know the sound scattering characteristics of the marine pipeline according to the requirements of the underwater vehicle on sound detection. The marine pipeline is a multi-layer composite structure, the structural parameters of each layer are uneven, and an anisotropic state exists, so that the sound scattering intensity of the marine pipeline calculated by a theoretical method is greatly different from the result of experimental measurement. Therefore, the experimental measurement of the sound scattering intensity of the marine pipeline is still an important means for evaluating the sound scattering property of the marine pipeline. However, when the sound scattering intensity of the marine pipeline is measured experimentally, there are also the following problems:

firstly, the outer diameter of the marine pipeline is smaller, generally 230mm, and the marine pipeline is wrapped by a multi-layer rubber structure, so that a scattering signal is weaker, namely the signal-to-noise ratio is very low, and if the measuring hydrophone is placed at a longer distance, the acoustic scattering signal of the marine pipeline cannot be measured;

secondly, the acoustic scattering intensity of the marine pipeline in the shallow sea is easily influenced by the reverberation of the sea bottom and the sea surface, and if the processing method is improper, the measured acoustic scattering intensity of the marine pipeline is larger;

thirdly, under the action of ocean current, the hydrophone attached to the surface of the ocean pipeline can be subjected to the blocking and backing effects of the ocean pipeline in the process of receiving the acoustic signal, so that the scattering signal is weak, and the acoustic scattering intensity is small;

finally, the test measurement of the sound scattering intensity in the shallow sea is carried out, the adopted transmitting sound sources are generally all nondirectional sound sources, and the key problem that attention needs to be paid in the test measurement process is how to calibrate the transmitting sound intensity of the nondirectional sound sources and how to reduce the reverberation intensity of the sea surface and the seabed.

Disclosure of Invention

The invention aims to provide a device and a method for measuring the sound scattering intensity of an ocean pipeline in shallow sea.

The purpose of the invention is realized as follows: the transmitting transducer is located in the center of the cylindrical frame, the first hydrophone is located on the outer side of the cylindrical frame, the special-shaped support is placed on the surface of an ocean pipeline, and the second hydrophone is placed on the outer side of the special-shaped support.

The invention also includes such structural features:

1. the cylindrical frame is a frame consisting of a top surface, side surfaces and a bottom surface, the top surface is made of concentric circles and supporting rods with different radiuses, the side surfaces are uniformly distributed straight rods, the bottom surface is made of concentric circles and supporting rods with different radiuses, a vertical rod is arranged in the cylindrical frame, the head of the vertical rod is a circular ring, and the transmitting transducer is positioned in the center of the cylindrical frame, namely the transmitting transducer is arranged on the circular ring; the top surface of the cylindrical frame is provided with a plurality of hollow spherical shells, the bottom surface of the cylindrical frame is provided with a plurality of sound-absorbing wedges, each straight rod on the side surface is evenly embedded with a first ceramic bearing, and the outer side of each first ceramic bearing is connected with a first flapping wing.

2. The special-shaped support comprises a plastic bearing, a cross rod, a vertical rod, a second ceramic bearing and a second flapping wing, the plastic bearing is embedded to the outer surface of the marine pipeline, the cross rod is embedded to the outer side of the plastic bearing, the end of the cross rod is connected with the middle of the vertical rod, the second ceramic bearing is uniformly arranged on the vertical rod, the second flapping wing is arranged on the second ceramic bearing, and the second hydrophone is placed on the outer side of the special-shaped support and is arranged at the lower end of the vertical rod.

3. The second hydrophone is at a distance of 0.5 times the outer diameter of the marine pipeline closest to the surface of the marine pipeline.

4. The transmitting transducer is an omnidirectional underwater sound transmitting transducer.

5. A method for measuring the sound scattering intensity of a pipeline in shallow sea comprises a device for measuring the sound scattering intensity of the pipeline in shallow sea, and comprises the following steps:

the first step is as follows: the transmitting transducer transmits a single-frequency CW pulse signal, narrow-band filtering is carried out on the signal acquired by the first hydrophone, and then Fourier transform is carried out to obtain the CW pulse signal with the amplitude P₁Narrow-band filtering is carried out on the signal acquired by the second hydrophone, and then Fourier transform is carried out to obtain the amplitude P of the CW pulse signal₂；

The second step is that: according to the distance L between the transmitting transducer and the first hydrophone₁Calculating the starting time of transmitting the CW pulse by the transmitting transducer according to the CW pulse signal acquired by the first hydrophone;

the third step: the CW pulse starting time determined by the second step is compared with the CW pulse starting time collected by the second hydrophone to determine the distance L between the transmitting transducer and the second hydrophone₂；

The fourth step: through L₁And L₂Comparing, calculating the direct wave amplitude P of CW pulse arriving in the second hydrophone according to the spherical wave expansion rule₃；

The fifth step: according to the formulaAnd calculating the sound scattering intensity of the marine pipeline.

Compared with the prior art, the invention has the beneficial effects that: firstly, a second hydrophone for measuring the sound scattering intensity near the marine pipeline is not tightly attached to the surface of the pipeline, so that the sound shielding and sound backing effects caused by the deformation of the marine pipeline under the action of ocean currents are avoided, and the hydrophone can reliably receive the sound scattering signals of the marine pipeline in the measuring process; secondly, a structure that a hollow spherical shell and a sound absorption wedge are placed on the cylindrical frame is adopted, so that sound waves incident to the sea surface and the sea bottom by the transmitting transducer can be effectively scattered and absorbed, and the influence of the sea bottom reverberation and the sea surface reverberation in the sound scattering signals of the marine pipeline is reduced; thirdly, the first flapping wing of the straight rod in the side surface of the cylindrical shell and the second flapping wing of the vertical rod outside the special-shaped support have two functions: on one hand, the energy in the incoming flow can be attenuated, and the low-frequency interference of large-scale vortex group pulsation on the measurement hydrophone is reduced, and on the other hand, as a flow guide device, the cylindrical frame and the special-shaped support can better follow the incoming flow direction in a flow field, and the impact of the flow on the cylindrical frame and the special-shaped support is weakened; finally, the device and the method for measuring the sound scattering intensity of the pipeline in the shallow sea provide a data processing method for the target scattering intensity test in the shallow sea environment.

The invention has the advantages that: firstly, the transmitting transducer adopted by the device for measuring the sound scattering intensity of the marine pipeline in the shallow sea is an omnidirectional transducer, when the sound wave is transmitted in the shallow sea, the sound wave can be incident to the marine pipeline certainly, and the problems that the sound wave beam is deviated and even no sound wave beam is incident to the marine pipeline, which are caused by the influence of ocean currents when the directional transducer transmits the sound wave, are avoided; secondly, a hollow spherical shell is arranged on the top surface of a cylindrical frame and a sound-absorbing wedge is arranged on the bottom surface of the cylindrical frame in the device for measuring the sound scattering intensity of the marine pipeline in the shallow sea, so that the phenomenon of turning, rolling and the like is not easy to occur under the action of ocean current under the condition that the center of gravity of the cylindrical frame is inclined downwards in water, and the problem of fracture of a transmitting transducer and a first hydrophone caused by winding and twisting of cables is avoided; finally, the transmitting transducer and the second hydrophone in the device for measuring the sound scattering intensity of the marine pipeline in the shallow sea can enable the second hydrophone to receive the sound scattering signal which is similar to the sound scattering signal of the marine pipeline under the sound wave normal incidence condition under the action of the flow field, particularly when the device is placed at the head of a test ship for use, so that the scattering intensity of the marine pipeline under the sound wave incidence angle of 0 degree can be obtained, the scattering intensity is maximum at the moment, the device can be used as a basis for evaluating the sound scattering intensity of the marine pipeline, and meanwhile, a test measuring device is provided for evaluating the sound scattering intensity of different marine pipelines.

Drawings

FIG. 1 is a schematic cross-sectional view of a cylindrical frame in an apparatus for measuring the sound scattering intensity of a marine pipeline in shallow sea;

FIG. 2 is a schematic top view of a cylindrical frame of an apparatus for measuring acoustic scattering intensity of a pipeline in the open sea at shallow sea;

FIG. 3 is a schematic view of the bottom of a cylindrical frame in an apparatus for measuring the sound scattering intensity of a marine pipeline in shallow sea;

FIG. 4 is a schematic cross-sectional view of a special-shaped bracket in an apparatus for measuring the sound scattering intensity of a marine pipeline in shallow sea;

FIG. 5 is a flow chart of a method of measuring the acoustic scattering intensity of a marine pipeline in shallow sea;

FIG. 6 is a time domain waveform of a first hydrophone measured in a marine pipeline scatterometry conducted in shallow sea;

FIG. 7 is a time domain waveform of a second hydrophone measured by a marine pipeline scatter test performed in shallow sea;

wherein, 1 is a transmitting transducer, 2 is a cylindrical frame, 3 is a first hydrophone, 4 is a special-shaped support, 5 is a second hydrophone, 6 is an ocean pipeline, 21 is a top surface, 22 is a side surface, 23 is a bottom surface, 24 is a hollow spherical shell, 25 is a sound absorption wedge, 26 is a vertical rod, 27 is a circular ring, 28 is a first ceramic bearing, 29 is a first flapping wing, 211 is a circular ring, 212 is a supporting rod, 221 is a straight rod, 231 is a circular ring, 232 is a supporting rod, 41 is a plastic bearing, 42 is a transverse rod, 43 is a vertical rod, 44 is a second ceramic bearing, and 45 is a second flapping wing.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

With reference to fig. 1 to 7, the device for measuring the sound scattering intensity of a marine pipeline in shallow sea of the present invention includes a transmitting transducer 1, a cylindrical frame 2, a first hydrophone 3, a special-shaped support 4, and a second hydrophone 5, where the transmitting transducer 1 is located in the center of the cylindrical frame 2, the first hydrophone 3 is located outside the cylindrical frame 2, the special-shaped support 4 is located outside the marine pipeline 6, and the second hydrophone 5 is located outside the special-shaped support 4.

The transmitting transducer 1 is a spherical transmitting transducer, manufactured by PCB corporation of usa, model 6829-17, resonant frequency 17kHz, transmitting sound source level 150dB, maximum applicable voltage 1000V, and used for transmitting CW pulse in experimental measurement.

The cylindrical frame 2 is made of stainless steel and comprises a top surface 21, a side surface 22 and a bottom surface 23, the top surface 21 is made of a plurality of concentric circles 211, a support rod 212 is welded on the circles 211, a hollow spherical shell 24 is placed on the top surface 21, the circles 211 are stainless steel traceless circles, the support rod 212 is a stainless steel rod, the hollow spherical shell 24 is a thin spherical shell made of stainless steel and used for scattering sound waves incident to the sea surface of the transmitting transducer 1, the side surface 22 is made of a plurality of straight rods 221, the straight rods 221 are stainless steel rods, the bottom surface 23 is made of a plurality of concentric circles 231, a support rod 232 is welded on the circle 231, a sound-absorbing wedge 25 is placed on the bottom surface 23, the circle 231 is a stainless steel traceless circle, the support rod 232 is a stainless steel rod, the sound-absorbing wedge 25 is a wedge structure made of rubber and used for absorbing sound waves incident to the sea bottom of the transmitting transducer 1, a vertical rod 26 is welded at the center of the top surface 21 of the cylindrical frame 2, a circular ring 27 is welded at the head of the upright 26, the upright 26 is a stainless steel rod, the length of the upright is half of the length of the cylindrical frame 2, the circular ring 27 is made of stainless steel and used for hanging the transmitting transducer 1, a plurality of first ceramic bearings 28 are nested on the straight rod 221, first flapping wings 29 are glued on the first ceramic bearings 28 by high-strength glue, the first ceramic bearings 28 are zirconia ceramic bearings, the first flapping wings 29 are made of polyurethane, and the line type is NACA 0012.

The first hydrophone 3 is a sound pressure hydrophone made of piezoelectric ceramics, the sensitivity is-173 dB (ref: 1uV/Pa), the measurement frequency range is 0.1Hz-20kHz, and the length of a cable is 50 m.

The special-shaped support 4 is composed of a plastic bearing 41, a cross rod 42, a vertical rod 43, a second ceramic bearing 44 and a second flapping wing 45, the plastic bearing 41 is embedded on the outer surface of the marine pipeline 6, the plastic bearing 41 is a PP plastic bearing, the cross rod 42 is embedded on the outer side of the plastic bearing 41, the cross rod 42 is made of carbon fibers, the other end of the cross rod 42 is connected with the middle part of the vertical rod 43, the vertical rod 43 is made of carbon fibers, a plurality of second ceramic bearings 44 are embedded on the vertical rod 43, the second flapping wing 45 is glued on the second ceramic bearing 44 by high-strength glue, the second ceramic bearing 44 is a zirconium oxide ceramic bearing, the second flapping wing 45 is made of polyurethane, and the linear type is NACA 0012.

The second hydrophone 5 is a sound pressure hydrophone made of piezoelectric ceramics, the sensitivity is-173 dB (ref: 1uV/Pa), the measurement frequency range is 0.1Hz-20kHz, and the length of a cable is 50 m.

The marine pipeline 6 is of a multi-layer composite structure, the inner layer is a steel skeleton, the outer layer is various rubber coating layers, and the outer diameter size is about 230 mm.

A method for measuring the sound scattering intensity of a pipeline at sea in shallow sea comprises the following steps:

firstly, a transmitting transducer 1 transmits a single-frequency CW pulse signal, narrow-band filtering is carried out on a signal acquired by a first hydrophone 3, and then Fourier transform is carried out to obtain the amplitude P of the CW pulse signal₁Narrow-band filtering is carried out on the signal collected by the second hydrophone 5, and then Fourier transform is carried out to obtain the amplitude P of the CW pulse signal₂；

Secondly, according to the distance L between the transmitting transducer 1 and the first hydrophone 3₁Calculating the starting time of transmitting the CW pulse by the transmitting transducer 1 according to the CW pulse signal collected by the first hydrophone 3;

thirdly, comparing the CW pulse starting time determined in the second step with the CW pulse starting time collected by the second hydrophone 5 to determine the distance L between the transmitting transducer 1 and the second hydrophone 5₂；

The fourth step, passing L₁And L₂Comparing, calculating the direct wave amplitude P of CW pulse arriving in the second hydrophone 5 according to the spherical wave expansion rule₃；

And fifthly, calculating the sound scattering intensity of the marine pipeline according to the formula (1-1).

In this embodiment, the frequency of CW pulses is 7kHz, the number of pulses is 10, the repetition period is 1Hz, and L₁Is 1m, L₂10.2m, the scattering intensity of the marine pipeline 6, calculated according to equation (1-1), is-20.0 dB.

In summary, the invention comprises a transmitting transducer, a cylindrical frame, a first hydrophone, a special-shaped support and a second hydrophone, wherein the transmitting transducer is positioned in the center of the cylindrical frame, the first hydrophone is positioned on the outer side of the cylindrical frame, the special-shaped support is placed on the surface of an ocean pipeline, and the second hydrophone is placed on the outer side of the special-shaped support; an apparatus for measuring the acoustic scattering intensity of a pipeline in the shallow sea, further comprising a method; the device and the method for measuring the sound scattering intensity of the marine pipeline in the shallow sea reduce the influence of reverberation from the sea surface and the sea bottom in the sound scattering signal of the marine pipeline, weaken low-frequency interference caused by the pulsation of a large vortex group of ocean current, are suitable for measuring the sound scattering intensity of the marine pipeline in the ocean current environments of the shallow sea and the like, avoid the problems of focusing and aligning of sound beams of a directional transducer and have good engineering application prospect.