A method for measuring the contribution of multi-path radiated noise of a ship's sea communication system

Abstract

The application discloses a kind of ship sea communication system multi-path radiation noise contribution separation measurement methods, it is related to ship underwater noise source test analysis technical field, by sea communication system closing water pump, establish the inverse frequency response function relational expression of underwater acoustic field target point and the exciting input position of each noise path of ship sea communication system, repeatedly measure multiple underwater acoustic field target points to obtain inverse frequency response function matrix, then underwater acoustic field target point position is placed hydrophone, opens water pump excitation source, measures the radiation noise of multiple underwater acoustic field target points, establishes the relational expression between inverse frequency response function matrix and underwater acoustic field target point radiation noise, the method for calculating pump different path under the excitation source characteristics using singular value decomposition, the contribution of different paths of ship sea communication system to underwater acoustic field target point radiation noise is measured.The present application ingeniously avoids the difficulty of arranging large exciter inside during forward test, and greatly improves the test efficiency.

Description

Technical Field

[0001] This invention relates to the field of underwater noise source testing and analysis technology for ships, specifically a measurement method for separating the contribution of multipath radiated noise in a ship's sea passage system. Background Technology

[0002] With the continuous improvement of low-noise main and auxiliary machinery, elastic components, and vibration isolation technologies in ships, the radiated noise from ship ventilation systems has become a key bottleneck in the control of underwater acoustic characteristics. From the perspective of acoustic energy transfer paths, the radiated noise from ventilation systems includes three paths (such as...). Figure 1 As shown): First, the vibration of the pump unit's mechanical equipment is transmitted to the ship's foundation through the vibration isolation raft, generating sound radiation. Second, the vibration of the sea passage system pipeline is transmitted to the ship's hull through the connecting flanges, generating sound radiation. Third, the internal flow noise of the sea passage pipeline is directly radiated at the sea passage through the internal fluid medium. To achieve precise control of the noise in the ship's sea passage system pipeline, it is first necessary to effectively evaluate the radiated noise control effect of the three transmission paths. The prerequisite is that the radiated noise components of the three transmission paths in the ship's sea passage system can be effectively separated. This is of vital importance for guiding the rational application of vibration reduction and noise reduction measures and optimizing the acoustic design of the ship's sea passage system.

[0003] Traditional experimental measurement methods mainly fall into two categories. One is the step-by-step operation method using a test bench, which gradually blocks the transmission path to obtain the contribution of each path to radiated noise. However, this method is only applicable to laboratory benches and cannot be used for on-site measurements. The second method is based on transmission path analysis, which calculates the contribution of each path to radiated noise by obtaining the excitation source characteristics and frequency response function. This method is widely used in the automotive NVH field. However, marine navigation systems have a more complex structure and more constraints: firstly, equipment and piping are not easy to disassemble; secondly, the equipment installation location is compact, and the operating space is limited, making it difficult to arrange high-power exciters. This means that in actual engineering, it is impossible to obtain the excitation source characteristics and frequency response functions of different paths in a marine navigation system.

[0004] Therefore, how to obtain the excitation source characteristics and frequency response functions of different paths in a ship's sea passage system on-site in actual engineering, and establish a new test method for separating the multipath radiated noise contribution of a ship's sea passage system, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of the prior art, the present invention provides a measurement method for the separation of multipath radiated noise contribution in a ship's sea passage system, which can effectively solve the problems of the prior art.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions; A method for measuring the contribution separation of multipath radiated noise in a ship's navigation system includes the following steps: S1. Select the radiated noise points along each path in the ship's navigation system as the excitation input locations, and deploy accelerometers or hydrophones.

[0007] S2. Turn off the pump excitation source in the ship's sea passage system to ensure there are no other sources of interference in the measurement area; select a point in the measurement area. As the location for the underwater excitation sound source, L hydrophones are arranged around the underwater excitation sound source. The underwater excitation sound source is turned on to provide reverse excitation to the ship's sea passage system. The response of the acceleration sensor or hydrophone arranged along each path in the ship's sea passage system is measured, and the response of the hydrophones around the underwater excitation sound source is measured simultaneously.

[0008] S3. Based on the response results of the hydrophones around the underwater excitation sound source obtained in step S2, establish the volume velocity of the underwater excitation sound source. The relational expression.

[0009] S4. Based on the response results of the acceleration sensors or hydrophones deployed along each path in the ship's navigation system obtained in step S2, and the underwater excitation sound source volume velocity established in step S3... Establish the relationship between the underwater acoustic field target point and the inverse frequency response function at each path excitation input position.

[0010] S5. Move the underwater excitation sound source to the remaining underwater sound field target point positions respectively. The number of underwater sound field target points is S. Repeat steps S2, S3 and S4 at each of the remaining underwater sound field target point positions to establish the relationship between the S underwater sound field target points and the inverse frequency response function matrix H at each path excitation input position.

[0011] S6. Turn off the underwater excitation source and remove the hydrophones around it; place the hydrophones at the target points of the underwater sound field, aligning their positions with the sound center of the underwater excitation source; turn on the water pump excitation source in the ship's sea passage system, maintain stable operation, and simultaneously measure the radiated noise p at multiple selected target points in the underwater sound field. s , s≤S-1; Establish the relationship between the reverse frequency response function matrix and the radiated noise at the target point in the underwater acoustic field.

[0012] S7. Based on the relationship between the reverse frequency response function matrix and the underwater sound field target point radiated noise in step S6, the excitation source characteristics of the water pump under different paths are calculated using the singular value decomposition method.

[0013] S8. Select the Sth underwater acoustic field target point as the verification point. Based on the reverse frequency response function vectors of the Sth underwater acoustic field target point and the excitation input positions of each path obtained in step S2, and based on the excitation source characteristics of the water pump under different paths obtained in step S7, calculate the radiated noise evaluation value of the water pump at the verification point under the operating state and the evaluation value of the contribution of different paths to the radiated noise. Establish the relationship between the contribution of different paths of the water pump to the radiated noise of the verification point, and realize the measurement of the contribution of different paths of the ship's sea passage system to the radiated noise of the underwater acoustic field target point.

[0014] Specifically, in step S1, the connection point between the water pump and the base in the ship's sea passage system is selected as the excitation input for path I, and an acceleration sensor is arranged at each excitation input position, for a total of K; the flange surface point in the sea passage system is selected as the excitation input for path II, and an acceleration sensor is arranged at each excitation input position, for a total of M.

[0015] Accelerometers installed at the connection point between the water pump and the base, perpendicular to the base, are arranged in a number no less than the number of vibration isolators; acceleration sensors installed at points on the surface of the pipeline flange are arranged in vertical, longitudinal, and axial directions, with a number no less than 3.

[0016] Specifically, in step S1, the location of the coupling section inside the pipeline in the ship's sea passage system is selected as the excitation input for path III, and hydrophones are arranged at each excitation input location, for a total of N.

[0017] The number of hydrophones N is determined based on the analysis frequency band. If the analysis frequency band is lower than the pipe cutoff frequency fe, then only one hydrophone is installed inside the pipe. The cutoff frequency is calculated using the following formula: ; In the formula, c is the speed of sound in the medium in the pipe, in meters per second; D is the diameter of the pipe, in meters.

[0018] Specifically, in step S2 The distance to the ship is r (in meters), and the depth is h (in meters); the distance d (in meters) between the hydrophones around the underwater excitation sound source and the sound center of the underwater excitation sound source; the measured response v of the acceleration sensor deployed at path I in the ship's navigation system. k Where k≤K; the response v of the accelerometer located at path II. m Where m≤M; the hydrophone response p at path III. n Where n≤N, the response p of the hydrophones around the underwater excitation sound source is obtained by synchronous measurement. l , where l≤L.

[0019] The underwater excitation sound source is either an electric / electromagnetic source or a plasma pulse source. If an electric / electromagnetic source is selected, frequency sweep excitation is performed at a sweep rate of 1 Hz / s. If a plasma pulse source is selected, pulse excitation is performed, with a repetition count of no less than 10 times. The distance d between the hydrophones arranged around the underwater excitation sound source and the sound center of the underwater excitation sound source satisfies the following conditions: ; In the formula, This represents the maximum size of the underwater excitation sound source, measured in meters. To analyze the wavelength corresponding to the frequency band, the unit is meters. f is the frequency corresponding to the analysis band, and the unit is Hz.

[0020] Specifically, in step S3, the volume velocity of the underwater excitation sound source... Relationship: ,in This indicates the density of water.

[0021] Specifically, the relationship between the underwater acoustic field target point and the inverse frequency response function at the excitation input positions of paths I, II, and III in step S4 is as follows: ; ; ; in Let be a K*1 order vector, representing the reverse frequency response function of the underwater acoustic field target point and the excitation position of path I; Let be an M*1 order vector, representing the reverse frequency response function of the underwater acoustic field target point and the excitation position of path II; is an N*1 order vector, representing the inverse frequency response function of the underwater acoustic field target point and the excitation position of path III.

[0022] Specifically, in step S5, the underwater acoustic field target point is located on a circle with radius r centered on the measuring vessel; the relationship between the S underwater acoustic field target points and the inverse frequency response function matrix H at the excitation input positions of paths I, II, and III is as follows: ; in, Let be an S*K matrix, representing the inverse frequency response function of all underwater acoustic field target points and the excitation input position of path I; It is an S*M order matrix, representing the inverse frequency response function of all underwater acoustic field target points and the excitation input position of path II; It is an S*N matrix, representing the inverse frequency response function of all underwater acoustic field target points and the excitation input position of path III; the number of underwater acoustic field target points S is greater than the number of excitation points O, O=K+M+N.

[0023] Specifically, the relationship between the inverse frequency response function matrix and the underwater acoustic field target point radiated noise in step S6 is as follows: ; in, This represents the equivalent excitation force at the excitation input position of path I; This represents the equivalent excitation force at the excitation input location of path II; This represents the equivalent excitation sound source intensity at the excitation input location of path III; Let S be the radiated noise pressure at the (S-1)th underwater acoustic field target point.

[0024] Specifically, in step S7, the singular value decomposition method is used to calculate the excitation source characteristics of the water pump under different paths: Singular value decomposition is used to decompose the inverse frequency response function matrix into the product of three specific matrices, thereby extracting the key structure in the data. Its expression is as follows: ; In the formula, It is a diagonal matrix; The diagonal elements are singular values. , ; and It is a unitary matrix whose column vectors are mutually orthogonal; The top right corner It is the conjugate transpose; Under unregularized conditions, the equations for solving the excitation source characteristics of the pump under different paths are: ; In the formula, H is the inverse of the inverse frequency response function matrix H, and p is the radiation noise matrix of the target point in the underwater acoustic field.

[0025] Under regularization conditions, the method for solving the excitation source characteristic equations for different pump paths is as follows: Introducing Tikhonov regularization, let the absolute error be... To minimize the error e, Tikhonov introduced a penalty function. When the first derivative of J with respect to F is zero, the error e has a minimum value, and F can be obtained as: ; In the formula, I is the identity matrix; This is the regularization parameter.

[0026] Regularization parameters are selected using the generalized cross-validation method gcv(*). : ; Obtain the excitation source characteristic vector of the water pump under different paths under regularization conditions. The equation: .

[0027] The excitation source characteristics of the water pump under different paths are calculated based on the relationship between the inverse frequency response function matrix and the radiated noise at the target point in the underwater sound field. .

[0028] Specifically, in step S8, the inverse frequency response function vectors of the Sth underwater acoustic field target point obtained in step S2 and the excitation input positions of paths I, II, and III are... Based on the excitation source characteristics of the water pump under different paths obtained in step S7 Establish the relationship between the contribution of different pump paths to the radiated noise at the verification point: ; in This represents the contribution of radiated noise from pump path I to the verification point. The contribution of water pump path II to the radiated noise at the verification point; This represents the contribution of water pump path III to the radiated noise at the verification point.

[0029] Compared with the known prior art, the technical solution provided by this invention has the following beneficial effects: (1) Avoiding the difficulty of disassembling the excitation source to measure the excitation characteristics in the traditional transmission path analysis method, it realizes the independent characterization of the excitation source characteristics of the water pump from the field measurement, including excitation force and sound source intensity, and reduces the complexity of measurement procedures and post-processing.

[0030] (2) The frequency response function between the excitation position and the target point of the underwater sound field is obtained by reciprocal reverse testing technology, which cleverly avoids the difficulty of arranging a large exciter inside during forward testing, and greatly improves the testing efficiency. The reverse frequency response function matrix at all interface positions can be obtained with a single excitation. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0032] Figure 1 A schematic diagram of the vibration-noise transmission sound channel in a ship's sea passage system; Figure 2 Flowchart for the measurement of multipath radiated noise contribution separation in ship navigation systems; Figure 3 This is a schematic diagram of a scaled-down compartment test model; Figure 4 Schematic diagram of the scaled-down module model and the spatial location of the underwater excitation sound source; Figure 5 Test results on the contribution of different paths of the sea passage system in a scaled-down module model to radiated noise. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0034] This invention discloses a method for measuring the contribution separation of multipath radiated noise in a ship's navigation system, comprising the following steps: S1. Select the radiated noise points along each path in the ship's navigation system as the excitation input locations, and deploy accelerometers or hydrophones.

[0035] S2. Turn off the pump excitation source in the ship's sea passage system to ensure there are no other sources of interference in the measurement area; select a point in the measurement area. As the location for the underwater excitation sound source, L hydrophones are arranged around the underwater excitation sound source. The underwater excitation sound source is turned on to provide reverse excitation to the ship's sea passage system. The response of the acceleration sensor or hydrophone arranged along each path in the ship's sea passage system is measured, and the response of the hydrophones around the underwater excitation sound source is measured simultaneously.

[0036] S3. Based on the response results of the hydrophones around the underwater excitation sound source obtained in step S2, establish the volume velocity of the underwater excitation sound source. The relational expression.

[0037] S4. Based on the response results of the acceleration sensors or hydrophones deployed along each path in the ship's navigation system obtained in step S2, and the underwater excitation sound source volume velocity established in step S3... Establish the relationship between the underwater acoustic field target point and the inverse frequency response function at each path excitation input position.

[0038] S5. Move the underwater excitation sound source to the remaining underwater sound field target point positions respectively. The number of underwater sound field target points is S. Repeat steps S2, S3 and S4 at each of the remaining underwater sound field target point positions to establish the relationship between the S underwater sound field target points and the inverse frequency response function matrix H at each path excitation input position.

[0039] S6. Turn off the underwater excitation source and remove the hydrophones around it; place the hydrophones at the target points of the underwater sound field, aligning their positions with the sound center of the underwater excitation source; turn on the water pump excitation source in the ship's sea passage system, maintain stable operation, and simultaneously measure the radiated noise p at multiple selected target points in the underwater sound field. s , s≤S-1; Establish the relationship between the reverse frequency response function matrix and the radiated noise at the target point in the underwater acoustic field.

[0040] S7. Based on the relationship between the reverse frequency response function matrix and the underwater sound field target point radiated noise in step S6, the excitation source characteristics of the water pump under different paths are calculated using the singular value decomposition method.

[0041] S8. Select the Sth underwater acoustic field target point as the verification point. Based on the reverse frequency response function vectors of the Sth underwater acoustic field target point and the excitation input positions of each path obtained in step S2, and based on the excitation source characteristics of the water pump under different paths obtained in step S7, calculate the radiated noise evaluation value of the water pump at the verification point under the operating state and the evaluation value of the contribution of different paths to the radiated noise. Establish the relationship between the contribution of different paths of the water pump to the radiated noise of the verification point, and realize the measurement of the contribution of different paths of the ship's sea passage system to the radiated noise of the underwater acoustic field target point.

[0042] The measurement steps for the multipath radiated noise contribution separation of the above-mentioned ship navigation system are as follows: Figure 2 Flowchart for measuring the contribution separation of multipath radiated noise in a ship's sea passage system.

[0043] Specifically, in step S1, the connection point between the water pump and the base in the ship's sea passage system is selected as the excitation input for path I, and an acceleration sensor is arranged at each excitation input position, for a total of K; the flange surface point in the sea passage system is selected as the excitation input for path II, and an acceleration sensor is arranged at each excitation input position, for a total of M.

[0044] Accelerometers installed at the connection point between the water pump and the base, perpendicular to the base, are arranged in a number no less than the number of vibration isolators; acceleration sensors installed at points on the surface of the pipeline flange are arranged in vertical, longitudinal, and axial directions, with a number no less than 3.

[0045] Specifically, in step S1, the location of the coupling section inside the pipeline in the ship's sea passage system is selected as the excitation input for path III, and hydrophones are arranged at each excitation input location, for a total of N.

[0046] The number of hydrophones N is determined based on the analysis frequency band. If the analysis frequency band is lower than the pipe cutoff frequency fe, then only one hydrophone is installed inside the pipe. The cutoff frequency is calculated using the following formula: ; In the formula, c is the speed of sound in the medium in the pipe, in meters per second; D is the diameter of the pipe, in meters.

[0047] Specifically, in step S2 The distance to the ship is r (in meters), and the depth is h (in meters); the distance d (in meters) between the hydrophones around the underwater excitation sound source and the sound center of the underwater excitation sound source; the measured response v of the acceleration sensor deployed at path I in the ship's navigation system. k Where k≤K; the response v of the accelerometer located at path II. m Where m≤M; the hydrophone response p at path III. n Where n≤N, the response p of the hydrophones around the underwater excitation sound source is obtained by synchronous measurement. l , where l≤L.

[0048] The underwater excitation sound source is either an electric / electromagnetic source or a plasma pulse source. If an electric / electromagnetic source is selected, frequency sweep excitation is performed at a sweep rate of 1 Hz / s. If a plasma pulse source is selected, pulse excitation is performed, with a repetition count of no less than 10 times. The distance d between the hydrophones arranged around the underwater excitation sound source and the sound center of the underwater excitation sound source satisfies the following conditions: ; In the formula, This represents the maximum size of the underwater excitation sound source, measured in meters. To analyze the wavelength corresponding to the frequency band, the unit is meters. f is the frequency corresponding to the analysis band, and the unit is Hz.

[0049] Specifically, in step S3, the volume velocity of the underwater excitation sound source... Relationship: ,in This indicates the density of water.

[0050] Specifically, the relationship between the underwater acoustic field target point and the inverse frequency response function at the excitation input positions of paths I, II, and III in step S4 is as follows: ; ; ; in Let be a K*1 order vector, representing the reverse frequency response function of the underwater acoustic field target point and the excitation position of path I; Let be an M*1 order vector, representing the reverse frequency response function of the underwater acoustic field target point and the excitation position of path II; is an N*1 order vector, representing the inverse frequency response function of the underwater acoustic field target point and the excitation position of path III.

[0051] Specifically, in step S5, the underwater acoustic field target point is located on a circle with radius r centered on the measuring vessel; the relationship between the S underwater acoustic field target points and the inverse frequency response function matrix H at the excitation input positions of paths I, II, and III is as follows: ; in, Let be an S*K matrix, representing the inverse frequency response function of all underwater acoustic field target points and the excitation input position of path I; It is an S*M order matrix, representing the inverse frequency response function of all underwater acoustic field target points and the excitation input position of path II; It is an S*N matrix, representing the inverse frequency response function of all underwater acoustic field target points and the excitation input position of path III; the number of underwater acoustic field target points S is greater than the number of excitation points O, O=K+M+N.

[0052] Specifically, the relationship between the inverse frequency response function matrix and the underwater acoustic field target point radiated noise in step S6 is as follows: ; in, This represents the equivalent excitation force at the excitation input position of path I; This represents the equivalent excitation force at the excitation input location of path II; This represents the equivalent excitation sound source intensity at the excitation input location of path III; Let S be the radiated noise pressure at the (S-1)th underwater acoustic field target point.

[0053] Specifically, in step S7, the singular value decomposition method is used to calculate the excitation source characteristics of the water pump under different paths: Singular value decomposition is used to decompose the inverse frequency response function matrix into the product of three specific matrices, thereby extracting the key structure in the data. Its expression is as follows: ; In the formula, It is a diagonal matrix; The diagonal elements are singular values. , ; and It is a unitary matrix whose column vectors are mutually orthogonal; The top right corner This is the conjugate transpose.

[0054] Under unregularized conditions, the equations for solving the excitation source characteristics of the pump under different paths are: ; In the formula, H is the inverse of the Green's function matrix H, and p is the radiation noise matrix of the target point in the underwater acoustic field.

[0055] Under regularization conditions, the method for solving the excitation source characteristic equations for different pump paths is as follows: Introducing Tikhonov regularization, let the absolute error be... To minimize the error e, Tikhonov introduced a penalty function. When the first derivative of J with respect to F is zero, the error e has a minimum value, and F can be obtained as: ; In the formula, I is the identity matrix; This is the regularization parameter.

[0056] Regularization parameters are selected using the generalized cross-validation method gcv(*). : ; Obtain the excitation source characteristic vector of the water pump under different paths under regularization conditions. The equation: .

[0057] The excitation source characteristics of the water pump under different paths are calculated based on the relationship between the inverse frequency response function matrix and the radiated noise at the target point in the underwater sound field. .

[0058] Specifically, in step S8, the inverse frequency response function vectors of the Sth underwater acoustic field target point obtained in step S2 and the excitation input positions of paths I, II, and III are... Based on the excitation source characteristics of the water pump under different paths obtained in step S7 Establish the relationship between the contribution of different pump paths to the radiated noise at the verification point: ; in This represents the contribution of radiated noise from pump path I to the verification point. The contribution of water pump path II to the radiated noise at the verification point; This represents the contribution of water pump path III to the radiated noise at the verification point.

[0059] The present invention will be further described below with reference to embodiments.

[0060] Example The test model for the ship's sea passage system is a scaled-down compartment model 1. The model is a double-layered, ribbed cylindrical shell. The interior includes a base 5, a circulating water tank 2, sea passage piping 3, and a centrifugal pump 4. See details below. Figure 3 As shown; the test area was set inside a bay with stable hydrological conditions. The water depth was approximately 60 meters, ranging from 30 meters to 500 meters from the shore. A scaled-down cabin model and an underwater excitation sound source device were placed at a depth of 20 meters for the test.

[0061] Step 1: Select the connection point between the water pump and the base in the scaled-down section model's sea passage system as the excitation input position for path I, and place an acceleration sensor at each excitation input position, for a total of 8 sensors; select the flange surface point of the pipeline in the scaled-down section model's sea passage system as the excitation input position for path II, and place an acceleration sensor at each excitation input position, with directions of vertical, longitudinal, and axial, for a total of 3 sensors.

[0062] Step 2: Select the location of the coupling section inside the pipeline in the scaled-down module model sea passage system as the excitation input location of path III. In this embodiment, the number of hydrophones is 1, the pipeline diameter is 80mm, and the cutoff frequency is 10kHz.

[0063] Step 3: Turn off the water pump excitation source in the scaled-down module model's sea passage system to ensure there are no other interfering sound sources in the measurement area; select 12 underwater sound field target points on a 15-meter radius circle centered on the scaled-down module model in the measurement area, spaced 30 degrees apart; the underwater excitation sound source can be a 50kJ plasma pulsed sound source, with pulse excitation repeated at least 10 times; arrange 4 hydrophones around the underwater excitation sound source, with a distance of 1 meter between the hydrophones and the sound center of the underwater excitation sound source; the spatial position diagram of the scaled-down module model and the underwater excitation sound source is shown below. Figure 4 As shown.

[0064] Step 4: Based on the response results of the hydrophones around the underwater excitation sound source obtained in Step 3, establish the volume velocity of the underwater excitation sound source. Relationship: ,in This indicates the density of water.

[0065] Step 5: Based on the response results of the accelerometer and hydrophone deployed at the excitation positions I, II, and III of the ship's sea passage system obtained in Step 3, calculate the reverse frequency response function of the underwater sound field target point and the excitation positions I, II, and III.

[0066] Step 6: Move the underwater sound source to the remaining underwater target locations. There are 12 underwater target locations. Repeat steps 3, 4, and 5 at each of the remaining underwater target locations to calculate the reverse frequency response function matrix H of the 12 underwater target locations and the excitation locations of paths I, II, and III.

[0067] Step 7: Turn off the underwater excitation sound source and remove the hydrophones around the underwater excitation sound source; place the hydrophones at the underwater target point locations; the placement of the hydrophones should coincide with the sound center of the underwater excitation sound source; turn on the water pump excitation source in the scaled-down module model's sea passage system, maintain stable operation, and simultaneously measure the radiated noise of multiple selected underwater target points.

[0068] Step 8: Based on the relationship between the reverse frequency response function matrix and the radiated noise of the underwater target point in Step 7, solve for the excitation source characteristics of the water pump; use the singular value decomposition method to calculate the excitation source characteristics of the water pump under different paths.

[0069] Step 9: Select one underwater target point as the verification point, calculate the radiated noise assessment value at the underwater verification point under pump operation conditions, and the assessment value of the contribution of different paths to the radiated noise, as detailed below. Figure 5 As shown.

[0070] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for measuring the contribution separation of multipath radiated noise in a ship's sea passage system, characterized in that, Includes the following steps: S1. Select the radiated noise points along each path in the ship's sea passage system as excitation input locations, and deploy accelerometers or hydrophones there; S2. Turn off the pump excitation source in the ship's sea passage system to ensure there are no other sources of interference in the measurement area; select a point in the measurement area. As the location for the underwater excitation sound source, L hydrophones are arranged around the underwater excitation sound source. The underwater excitation sound source is turned on to provide reverse excitation to the ship's sea passage system. The response of the acceleration sensor or hydrophone arranged in each path of the ship's sea passage system is measured, and the response of the hydrophones around the underwater excitation sound source is measured simultaneously. S3. Based on the response results of the hydrophones around the underwater excitation sound source obtained in step S2, establish the volume velocity of the underwater excitation sound source. Relationship; S4. Based on the response results of the acceleration sensors or hydrophones deployed along each path in the ship's navigation system obtained in step S2, and the underwater excitation sound source volume velocity established in step S3... Establish the relationship between the underwater acoustic field target point and the inverse frequency response function at each path excitation input position; S5. Move the underwater excitation sound source to the remaining underwater sound field target point positions respectively. The number of underwater sound field target points is S. Repeat steps S2, S3 and S4 at each of the remaining underwater sound field target point positions to establish the relationship between the S underwater sound field target points and the inverse frequency response function matrix H at each path excitation input position. S6. Turn off the underwater excitation source and remove the hydrophones around it; place the hydrophones at the target points of the underwater sound field, aligning their positions with the sound center of the underwater excitation source; turn on the water pump excitation source in the ship's sea passage system, maintain stable operation, and simultaneously measure the radiated noise at multiple selected target points in the underwater sound field. p s , s≤S-1; Establish the relationship between the reverse frequency response function matrix and the radiated noise at the target point in the underwater acoustic field; S7. Based on the relationship between the reverse frequency response function matrix and the radiated noise of the underwater sound field target point in step S6, the characteristics of the excitation source of the water pump under different paths are calculated by the singular value decomposition method. S8. Select the Sth underwater acoustic field target point as the verification point. Based on the reverse frequency response function vectors of the Sth underwater acoustic field target point and the excitation input positions of each path obtained in step S2, and based on the excitation source characteristics of the water pump under different paths obtained in step S7, calculate the radiated noise evaluation value of the water pump at the verification point under the operating state and the evaluation value of the contribution of different paths to the radiated noise. Establish the relationship between the contribution of different paths of the water pump to the radiated noise of the verification point, and realize the measurement of the contribution of different paths of the ship's sea passage system to the radiated noise of the underwater acoustic field target point.

2. The measurement method for separating the multipath radiated noise contribution of a ship's sea passage system according to claim 1, characterized in that, In step S1, the connection point between the water pump and the base in the ship's sea passage system is selected as the excitation input for path I, and an acceleration sensor is arranged at each excitation input position, for a total of K; the flange surface point in the ship's sea passage system is selected as the excitation input for path II, and an acceleration sensor is arranged at each excitation input position, for a total of M. Accelerometers installed at the connection point between the water pump and the base, perpendicular to the base, are arranged in a number no less than the number of vibration isolators; acceleration sensors installed at points on the surface of the pipeline flange are arranged in vertical, longitudinal, and axial directions, with a number no less than 3.

3. The measurement method for separating the multipath radiated noise contribution of a ship's sea passage system according to claim 2, characterized in that, In step S1, the location of the coupling section inside the pipeline in the ship's sea passage system is selected as the excitation input for path III, and hydrophones are arranged at each excitation input location, for a total of N. The number N of hydrophones installed is determined based on the analysis frequency band. If the analysis frequency band is lower than the pipe cutoff frequency... f e If only one hydrophone is installed inside the pipe, the cutoff frequency is calculated using the following formula: ； In the formula, c The velocity of sound in the pipeline medium is expressed in meters per second. D This refers to the diameter of the pipe, measured in meters.

4. The measurement method for separating the multipath radiated noise contribution of a ship's sea passage system according to claim 3, characterized in that, In step S2 The distance to the ship is denoted by r in meters, and the depth is denoted by h in meters. Distance between the hydrophones around the underwater excitation sound source and the sound center of the underwater excitation sound source d， The unit is meters; the response of the acceleration sensor deployed at location I in the ship's navigation system was measured. v k Where k≤K; the response of the accelerometer placed at path II. v m where m≤M; Hydrophone response at path III p n Where n≤N, the response of hydrophones around the underwater excitation sound source is measured synchronously. p l where l≤L; The underwater excitation sound source is either an electric / electromagnetic source or a plasma pulse source. If an electric / electromagnetic source is selected, frequency sweep excitation is performed at a sweep rate of 1 Hz / s. If a plasma pulse source is selected, pulse excitation is performed, with repetitions of no less than 10 times. The distance between the hydrophones arranged around the underwater excitation sound source and the sound center of the underwater excitation sound source is... d The following conditions must be met: ； In the formula, This represents the maximum size of the underwater excitation sound source, measured in meters. To analyze the wavelength corresponding to the frequency band, the unit is meters. , f The frequency corresponding to the analysis band is in Hz.

5. The measurement method for separating the multipath radiated noise contribution of a ship's sea passage system according to claim 4, characterized in that, In step S3, the volume velocity of the underwater excitation sound source Relationship: ,in This indicates the density of water.

6. The measurement method for separating the multipath radiated noise contribution of a ship's sea passage system according to claim 5, characterized in that, The relationship between the underwater acoustic field target point and the inverse frequency response function at the excitation input positions of paths I, II, and III in step S4 is as follows: ； ； ； in For K A first-order vector representing the inverse frequency response function of the underwater acoustic field target point and the excitation position of path I; For M A first-order vector, representing the inverse frequency response function of the underwater acoustic field target point and the excitation position of path II; For N The first-order vector represents the inverse frequency response function of the underwater acoustic field target point and the excitation position of path III.

7. The method for measuring the contribution separation of multipath radiated noise in a ship's sea passage system according to claim 6, characterized in that, In step S5, the underwater acoustic field target points are located on a circle with radius r centered on the measuring vessel; the relationship between the S underwater acoustic field target points and the inverse frequency response function matrix H at the excitation input positions of paths I, II, and III is as follows: ； in, For S A K-order matrix, representing the inverse frequency response function of all underwater acoustic field target points and the excitation input position of path I; For S An M-order matrix, representing the inverse frequency response function of all underwater acoustic field target points and the path II excitation input position; For S An N-order matrix representing the inverse frequency response function of all underwater acoustic field target points and the excitation input position of path III; the number of underwater acoustic field target points S is greater than the number of excitation points O, O=K+M+N.

8. The method for measuring the contribution separation of multipath radiated noise in a ship's sea passage system according to claim 7, characterized in that, The relationship between the inverse frequency response function matrix and the underwater acoustic field target point radiated noise in step S6 is as follows: ； in, This represents the equivalent excitation force at the excitation input position of path I; This represents the equivalent excitation force at the excitation input location of path II; This represents the equivalent excitation sound source intensity at the excitation input location of path III; Let S be the radiated noise pressure at the (S-1)th underwater acoustic field target point.

9. The method for measuring the contribution separation of multipath radiated noise in a ship's sea passage system according to claim 8, characterized in that, In step S7, the singular value decomposition method is used to calculate the excitation source characteristics of the water pump under different paths: Singular value decomposition is used to decompose the inverse frequency response function matrix into the product of three specific matrices, thereby extracting the key structure in the data. Its expression is as follows: ； In the formula, It is a diagonal matrix; The diagonal elements are singular values. , ; and It is a unitary matrix whose column vectors are mutually orthogonal; The top right corner It is the conjugate transpose; Under unregularized conditions, the equations for solving the excitation source characteristics of the pump under different paths are: ； In the formula, The inverse frequency response function matrix H The reverse, p Here is the radiated noise matrix of the target point in the underwater acoustic field; Under regularization conditions, the method for solving the excitation source characteristic equations for different pump paths is as follows: Introducing Tikhonov regularization, let the absolute error be... To minimize the error e, Tikhonov introduced a penalty function. When the first derivative of J with respect to F is zero, the error e has a minimum value, then we can obtain... F for: ； In the formula, I For unit array; For regularization parameters; Using the generalized cross-validation method gcv ( Choose regularization parameters : ； Obtain the excitation source characteristic vector of the water pump under different paths under regularization conditions. The equation: ； The excitation source characteristics of the water pump under different paths are calculated based on the relationship between the inverse frequency response function matrix and the radiated noise at the target point in the underwater sound field. 。 10. A method for measuring the contribution separation of multipath radiated noise in a ship's sea passage system according to claim 9, characterized in that, In step S8, the inverse frequency response function vectors of the Sth underwater acoustic field target point and the excitation input positions of paths I, II, and III obtained in step S2 are used. Based on the excitation source characteristics of the water pump under different paths obtained in step S7 Establish the relationship between the contribution of different pump paths to the radiated noise at the verification point: ； in This represents the contribution of radiated noise from pump path I to the verification point. The contribution of water pump path II to the radiated noise at the verification point; This represents the contribution of water pump path III to the radiated noise at the verification point.

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