CN113432832B - Test device for measuring flow-induced noise and vortex-induced noise of marine pipeline - Google Patents

Abstract

The invention provides a test device for measuring flow-induced noise and vortex-induced noise of ocean pipelines, which includes a pipe sleeve, a connection mechanism, a vibration reduction mechanism, a diversion grid and a self-contained hydrophone, and the pipe sleeve is installed on the outer surface of the ocean pipeline , one end of the connecting mechanism is placed in the pipe sleeve, the other end is connected to the vibration damping mechanism, the vibration damping mechanism is connected to the diversion grid, and the self-contained hydrophone is placed in the diversion grid; the measurement of flow-induced noise and vortex-induced noise of ocean pipelines The test device avoids the acoustic near-field effect caused by the insufficient distance between the hydrophone and the submarine pipeline in the conventional test method. Due to the low-frequency interference caused by external ocean currents during the test, the design of the vibration reduction mechanism makes the normalization of the flow-induced noise and vortex-induced noise of the ocean pipeline more accurate, and the measurement results are more reliable. The experimental measurement of the excitation noise provides technical support.

Description

A test device for measuring flow-induced noise and vortex-induced noise of marine pipelines

technical field

The invention relates to a test device for measuring flow-induced noise and vortex-induced noise of ocean pipelines, belonging to the field of acoustic measurement.

Background technique

At present, the flow-induced noise generated by the offshore pipeline under the excitation of internal oil flow, air flow and its multi-phase medium, and the vortex-induced noise generated by the external ocean current excitation of the offshore pipeline have attracted attention, because the flow-induced noise and vortex-induced noise will affect the surrounding environment. The navigation and detection capabilities of working underwater vehicles, UUV, etc., but how to accurately measure the flow-induced noise and vortex-induced noise of ocean pipelines is very difficult. Specifically in:

First, the magnitude of flow-induced noise and vortex-induced noise of ocean pipelines is often relatively small, because the flow velocity inside ocean pipelines is generally not greater than 2m/s, and the velocity of ocean currents outside ocean pipelines is generally not more than 2m/s. The magnitude of flow-induced noise and vortex-induced noise is not much different from the background noise under different flow conditions, that is, the signal-to-noise ratio is very low;

Second, the hydrophone is very susceptible to the effect of turbulent fluctuating pressure during the measurement process of the flow-induced noise and vortex-induced noise of the ocean pipeline, that is, the output "false sound". Because the volume of the hydrophone is limited, the wave number-frequency spectrum The high-frequency component has a better averaging and filtering effect, that is, it has a better ability to reduce the "false sound" high-frequency part, while the low-frequency component has a very limited averaging effect on the surface of the hydrophone because of the large vortex and small wave number. , will bring extremely strong low-frequency interference in the measurement signal;

Third, the internal ocean currents near the ocean pipeline will change all the time, blocked by the ocean pipeline, which makes the state of the ocean current change all the time. If the hydrophone used for measurement cannot change with the state of the ocean pipeline in the ocean current, it will cause The measurement results are inaccurate, for example, when the measuring hydrophone is directly impacted by ocean currents, it will output a high electrical signal;

Finally, if the position of the hydrophone relative to the ocean pipeline shifts during the acquisition process, it will cause problems in the calculation of the sound pressure level of the ocean pipeline's flow-induced noise and vortex-induced noise, and the flow-induced noise and vortex-induced noise of the ocean pipeline cannot be accurately estimated. excited noise.

In the past, most of the research on offshore pipelines focused on the process of oil wax deposition and pipeline corrosion resistance, and little or no attention was paid to the measurement of flow-induced noise and vortex-induced noise of marine pipelines, making this research very little.

Contents of the invention

The object of the present invention is to provide a test device for measuring flow-induced noise and vortex-induced noise of ocean pipelines.

The purpose of the present invention is achieved in this way: including a pipe sleeve, a connecting mechanism, a damping mechanism, a diversion grid, and a self-contained hydrophone, the pipe sleeve is installed on the outer surface of the ocean pipeline, and one end of the connecting mechanism is placed in the pipe sleeve , the other end of the connection mechanism is connected to the vibration damping mechanism, the vibration damping mechanism is connected to the diversion grid, and the self-contained hydrophone is placed in the diversion grid.

The present invention also includes such structural features:

1. The pipe sleeve is a circular structure, the inside of the pipe sleeve is hollow, and balls are placed, and the outer surface of the pipe sleeve is grooved.

2. The head end of the connection mechanism is spherical and embedded in the sleeve, the middle part of the connection mechanism is a thin airfoil with smooth transition, and the interior of the middle part of the connection mechanism is hollow, and the tail end of the connection mechanism is cylindrical.

3. The shape of the damping mechanism is cylindrical, and there is a plastic bearing at the outer end of the damping mechanism. The other end of the connecting mechanism is connected to the damping mechanism. The other end of the mechanism has a through hole, and there is a spring inside the damping mechanism. There is a snap ring in the middle of the spring. The connecting rod on the snap ring is connected to the guide grid through the through hole at the other end of the damping mechanism. It is a hollow structure.

4. The diversion grid includes fixed rods and grids evenly arranged on the fixed rods. The overall diversion grid is a cage configuration with conical ends and a cylindrical middle part; the front part of each grid is a sheet structure , the middle part of the grid is a thin airfoil with smooth transition, the tail of the grid is a sheet structure, the outer side of the middle part of the grid is the trailing edge of the thin airfoil, and the inner side of the middle part of the grid is the head of the thin airfoil; The inner molding cavity of the grid.

5. The self-contained hydrophone is installed on the fixed rod in the diversion grid.

Compared with the prior art, the beneficial effects of the present invention are: firstly, the sleeve is installed on the surface of the ocean pipeline, and one end of the connecting mechanism is embedded in the inside of the sleeve and can slide inside, and the thin airfoil structure of the connecting mechanism itself can Under the action of external ocean currents, it drives the vibration damping mechanism, diversion grid and self-contained hydrophone to move, so that the connection mechanism, vibration damping mechanism, diversion grid and self-contained hydrophone are always in the ocean pipeline The flow downstream under the impact of the ocean current slows down the impact of the incoming flow on the connecting mechanism, the damping mechanism, the diversion grid and the self-contained hydrophone, and reduces the generation of hydrodynamic noise; secondly, the plastic at the front end of the damping mechanism The bearing can make the vibration damping mechanism, diversion grid and self-contained hydrophone rotate under the action of incoming flow, which can better reduce the torque effect of the turbulent flow in the ocean current on the diversion grid; again, the vibration damping mechanism As a "mass-spring" structure, the spring in the structure can attenuate the periodic oscillation of the ocean pipeline when the Karman vortex street phenomenon is generated by the excitation of the ocean current, and reduce the oscillation caused by the self-contained hydrophone in the process of receiving acoustic signals. Finally, when the large vortex flows through the surface of the hydrophone, due to the small size of the hydrophone, the averaging effect on the low wavenumber components in the frequency-wavenumber spectrum is limited, so that there are The strong low-frequency components lead to high low-frequency interference. The thin airfoil structure on the surface of the diversion grid can destroy the incoming flow and make it into a very small vortex cluster, so that the low-frequency components caused by these large vortex clusters can disappear. The signal output by the self-contained hydrophone is not interfered by the low frequency component.

The connecting mechanism, damping mechanism, diversion grid and self-contained hydrophone in the present invention are basically in a suspended state in the water, and are not affected by their own gravity, so that when calculating the flow-induced noise and vortex-induced noise of the ocean pipeline The distance parameter is relatively simple, that is, the flow-induced noise and vortex-induced noise generated by the ocean pipeline can be accurately calculated according to the law of cylindrical wave expansion; Although the connection of the hydrophone has been elastically treated, the distance can still be calculated according to the rigid connection structure, which is convenient for accurate calibration of the measured flow-induced noise and vortex-induced noise; again, the invention adopts the connection mechanism, vibration reduction The mechanism, diversion grid and self-contained hydrophone collect the flow-induced noise and vortex-induced noise of the ocean pipeline, so that the hydrophone is in the far-field area of noise measurement, avoiding the close-up of the flow-induced noise and vortex-induced noise of the ocean pipeline. The field effect makes the measurement results and estimations more accurate; finally, the size of the connecting mechanism, damping mechanism, and diversion grid in this invention can be adjusted according to the strength of the flow-induced noise and vortex-induced noise of the ocean pipeline. When the flow-induced noise and When the vortex-induced noise is strong, a larger size can be used to keep the self-contained hydrophone away from the ocean pipeline; when the flow-induced noise and vortex-induced noise are weak, a smaller size can be used to keep the self-contained hydrophone The sensor is close to the ocean pipeline, so as to meet the signal-to-noise ratio requirements in the measurement process, and avoid the problem of insufficient signal-to-noise ratio at the acoustic absolute far-field condition, and has a good signal-to-noise ratio adjustment capability.

Description of drawings

Fig. 1 is a schematic longitudinal section of a test device for measuring flow-induced noise and vortex-induced noise of marine pipelines;

Fig. 2 is the top view of connecting mechanism;

Fig. 3 is the schematic diagram of the longitudinal section of the grid in the diversion grid;

Fig. 4 is the top view of the grid in the diversion grid;

Among them, 10 is an ocean pipeline, 1 is a pipe sleeve, 11 is a ball, 2 is a connecting mechanism, 21 is a head, 22 is a middle part, 23 is a tail end, 24 is a cavity, 3 is a damping mechanism, 31 is a plastic bearing, 32 is a spring, 33 is a snap ring, 34 is a connecting rod, 35 is a shell, 36 is a cavity, 4 is a diversion grid, 41 is a grid, 42 is a cavity, 43 is a fixing rod, 5 is a self-contained water tank hearing device.

detailed description

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

1 to 4, a test device for measuring flow-induced noise and vortex-induced noise of marine pipelines according to the present invention includes a pipe sleeve 1, a connection mechanism 2, a vibration reduction mechanism 3, a diversion grid 4 and a self-contained hydrophone 5, the pipe sleeve 1 is located outside the ocean pipeline 10, the head 21 of the connection mechanism 2 is placed in the pipe sleeve 1, the tail end 23 of the connection mechanism 2 is connected with the plastic bearing 31 of the vibration damping mechanism 3, the vibration damping mechanism 3 The connecting rod 34 is connected to one end of the diversion grid 4 , and the self-contained hydrophone 5 is placed in the diversion grid 4 .

The sleeve is of circular structure, the inside of the sleeve is hollow, balls are placed, and the outer surface of the sleeve is grooved; the sleeve 1 is made of stainless steel, and the inner diameter of the sleeve 1 is slightly smaller than the outer diameter of the ocean pipeline 10, so that the pipe The sleeve 1 is securely fastened to the outside of the marine pipeline 10. Inside the sleeve 1, there are multiple slideways composed of balls 11. The outer side of the sleeve 1 is slotted, and the head 21 of the connecting mechanism 2 can be placed on the sleeve 1. Inside, it can slide freely in a plurality of slideways formed by the balls 11.

One end of the connecting mechanism is spherical and embedded into the sleeve. The middle part of the connecting mechanism is hollow inside. The middle part of the connecting mechanism is a thin airfoil with a smooth transition. The other end of the connecting mechanism is cylindrical. The connecting mechanism is suspended in the water The connecting mechanism 2 is made of high-density polyurethane, and the connecting mechanism 2 is composed of a head 21, a middle part 22, a tail end 23 and a cavity 24. The head 21 is a homogeneous spherical shape, and the middle part 22 is a thin airfoil with smooth transition. The connection between 22 and the head 21 is the leading edge of the thin airfoil, and the connection between the middle part 22 and the tail end 23 is the trailing edge of the thin airfoil. The configuration of the thin airfoil is NACA0021, and a cavity 24 is formed inside the middle part 22. The tail end 23 is a homogeneous cylinder. During the stamping process, the total gravity and buoyancy are calculated according to the volumes of the head 21, middle portion 22 and tail end 23, and the volume of the cavity 24 is designed so that it becomes suspended in water.

The shape of the damping mechanism is cylindrical. There is a plastic bearing at one end of the damping mechanism, and a hole is opened at the other end of the damping mechanism. There is a spring inside the damping mechanism. There is a snap ring in the middle of the spring, and the connection on the snap ring The rod is connected to the diversion grid through the through hole at the other end of the damping mechanism, the outer surface of the damping mechanism is a hollow structure, and the damping mechanism is in a suspended state in the water; the damping mechanism 3 is composed of a plastic bearing 31, a spring 32, and a snap ring 33 , connecting rod 34, shell 35, and cavity 36. The configuration of the damping mechanism 3 is a double-layer cylindrical shell made of carbon fiber material. The plastic bearing 31 is installed on the front of the damping mechanism 3, and the spring 32 is installed on Inside the vibration mechanism 3, the spring 32 is made of stainless steel, the snap ring 33 is placed in the middle of the spring 32, the snap ring 33 is made of stainless steel, one end of the connecting rod 34 is connected to the snap ring 33, and the other end of the connecting rod 34 passes through the double layer The through hole at one end of the cylindrical shell is connected to one end of the diversion grille 4. The shell 35 is a double-layer sealed structure, and a cavity 36 is formed inside. The buoyancy generated by the cavity 36 in water can better balance the vibration damping mechanism 3. Gravity makes the damping mechanism 3 in a suspended state in the water.

The two ends of the diversion grid are conical structures, the middle part of the diversion grid is a cylindrical structure, and there are fixed rods on the axis. It is connected with the connecting rod of the damping mechanism; the diversion grid 4 is composed of a grid 41, a cavity 42 and a fixed rod 43. The front part of the diversion grid 4 is a conical configuration, the middle part is a cylindrical configuration, and the tail is a conical configuration , the grid 41 is made of polyurethane, the front part of the grid 41 is a sheet structure, the middle part of the grid 41 is a thin airfoil with smooth transition, and the outer side of the middle part of the grid 41 is the trailing edge of the thin airfoil. The inner side of the middle part of 41 is the head of the thin airfoil, the thin airfoil line type is NACA0021, the tail of the grid 41 is a sheet structure, and the cavity 42 is formed inside the grid 41, and the fixing rod 43 is a wooden structure to fix the airfoil. The rod 43 is an axis, and the grid 41 is installed on the fixed rod 43 to form a mesh cage configuration.

The self-contained hydrophone is installed on the fixed rod in the diversion grid; after the self-contained hydrophone is installed in the diversion grid, the diversion grid and the self-contained hydrophone are suspended in the water; the self-contained hydrophone Hydrophone 5 is a U-6 self-contained hydrophone, which is a self-contained, single-node, and miniaturized signal comprehensive monitoring equipment, which can effectively overcome the long deployment time of traditional submersible buoys, complex recovery methods, and vulnerability to weather conditions. The disadvantages of impact. Main features: Continuous sampling rate up to 128kHz, 128GB large-capacity high-density storage medium, low power consumption, working time up to 1 year, fast assembly, hydrophone vibration reduction design, system working depth up to 6000 meters.

According to the gravity of the self-contained hydrophone 5 in the water, calculate the buoyancy that the diversion grid 4 needs to provide, adjust the number of grids 41, and ensure that the diversion grid 4 and the self-contained hydrophone 5 are in a suspended state in the water.

Using the test device for measuring the flow-induced noise and vortex-induced noise of the ocean pipeline made in this embodiment, the flow-induced noise and the vortex-induced noise of the ocean pipeline were measured in the turbid sea area. The inner diameter of the ocean pipeline was 50mm, and the The outer diameter of the pipe is 86mm, and it is made of multiple rubber layers. The maximum flow velocity inside the ocean pipeline in the test is 2.0m/s, and the flow velocity of the ocean current is about 0.1m/s. After testing, it is found that: the flow of the ocean pipeline The total sound level of noise and vortex-induced noise increases with the increase of incoming flow, which is approximately linear, about 1.22dB/0.1(m/s).

In summary, the present invention includes a pipe sleeve, a connecting mechanism, a vibration damping mechanism, a diversion grid and a self-contained hydrophone. Vibration damping mechanism, the vibration damping mechanism is connected to the diversion grid, and the self-contained hydrophone is placed in the diversion grid; the test device for measuring the flow-induced noise and vortex-induced noise of the ocean pipeline avoids the hydrophone failure in the conventional test method. The acoustic near-field effect caused by the insufficient distance from the submarine pipeline, the use of the diversion grid to eliminate the influence of the large vortex pulsation pressure on the hydrophone, and reduce the low-frequency interference caused by the external ocean current during the test process. The design of the vibration reduction mechanism makes the normalization of the flow-induced noise and vortex-induced noise of the marine pipeline more accurate, and the measurement results are more reliable, which provides technical support for the experimental measurement of the flow-induced noise and vortex-induced noise of the marine pipeline.

Claims (7)

1. A test device for measuring flow-induced noise and vortex-induced noise of ocean pipelines, characterized in that: it comprises a pipe sleeve, a connecting mechanism, a damping mechanism, a diversion grid, and a self-contained hydrophone, and the pipe sleeve is installed on the ocean pipeline One end of the connecting mechanism is placed in the sleeve, the other end of the connecting mechanism is connected to the vibration damping mechanism, the vibration damping mechanism is connected to the diversion grid, and the self-contained hydrophone is placed in the diversion grid; the shape of the vibration damping mechanism It is cylindrical, and there is a plastic bearing at one end of the vibration damping mechanism. The other end of the connection mechanism is connected to the vibration damping mechanism, which means that the tail end of the connection mechanism is connected to the vibration damping mechanism through a plastic bearing; the other end of the vibration damping mechanism has a through hole. There is a spring inside the damping mechanism, and a snap ring is arranged in the middle of the spring. The connecting rod on the snap ring is connected with the diversion grid through the through hole at the other end of the damping mechanism, and the outer surface of the damping mechanism is a hollow structure. 2. A test device for measuring flow-induced noise and vortex-induced noise of marine pipelines according to claim 1, characterized in that: the pipe sleeve is a ring-shaped structure, the inside of the pipe sleeve is hollow, and balls are placed on the outside of the pipe sleeve. Grooved surface. 3. A test device for measuring flow-induced noise and vortex-induced noise of marine pipelines according to claim 1 or 2, characterized in that: one end of the head of the connecting mechanism is spherical and embedded in the sleeve, and the middle of the connecting mechanism The part is a thin airfoil with smooth transition, and the middle part of the connecting mechanism is hollow inside, and the tail end of the connecting mechanism is cylindrical. 4. A test device for measuring flow-induced noise and vortex-induced noise of marine pipelines according to claim 1 or 2, characterized in that: the diversion grid comprises a fixed rod, a grid evenly arranged on the fixed rod, and the diversion The overall grid is a cage configuration with conical ends and a cylindrical middle; the front of each grid is a sheet structure, the middle of the grid is a thin airfoil with a smooth transition, and the tail of the grid is a sheet structure. The outer side of the middle part of the grid is the tail edge of the thin airfoil, and the inner side of the middle part of the grid is the head of the thin airfoil; a cavity is formed inside the grid. 5. A test device for measuring flow-induced noise and vortex-induced noise of marine pipelines according to claim 3, characterized in that: the diversion grid includes a fixed rod, a grid evenly arranged on the fixed rod, and the diversion grid is as a whole It is a cage configuration with conical ends and a cylindrical middle; the front of each grid is a sheet structure, the middle of the grid is a thin airfoil with a smooth transition, and the tail of the grid is a sheet structure. The outer side of the middle part is the trailing edge of the thin airfoil, and the inner side of the middle part of the grid is the head of the thin airfoil; a cavity is formed inside the grid. 6. A test device for measuring flow-induced noise and vortex-induced noise of ocean pipelines according to claim 4, characterized in that: the self-contained hydrophone is installed on a fixed rod in the diversion grid. 7. A test device for measuring flow-induced noise and vortex-induced noise of ocean pipelines according to claim 5, characterized in that: the self-contained hydrophone is installed on a fixed rod in the diversion grid.

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