Method and system for analyzing uncertainty of ship quay wall effect hydrodynamic force and medium

Abstract

The invention discloses an uncertainty analysis method and system for ship quay wall effect hydrodynamic force and a medium. The method comprises the following steps that a test error source is determined; calculating the deviation limit of the ship quay wall effect hydrodynamic force; calculating the precision limit of the ship quay wall effect hydrodynamic force; and calculating the uncertainty of the ship quay wall effect hydrodynamic force. According to the method, test error sources of ships limiting water areas are classified, influence factors of water depth and ship-shore distance are introduced into measurement of hydrodynamic force deviation, a calculation method of ship model navigational speed uncertainty is provided based on a circulating water tank, and a function relationship between ship shore wall effect hydrodynamic force and each test error source is established. The reliable hydrodynamic uncertainty can be obtained, and technical support is provided for analyzing the uncertainty of test results.

Description

Technical Field

[0001] The present invention relates to the technical field of ship hydrodynamic testing, and in particular to an uncertainty analysis method, system and medium for ship quayside effect hydrodynamics. Background Art

[0002] Wall effect testing is an important method for studying the maneuverability of ships in confined waters. The nearshore test is a relatively simple and representative test, focusing on the hydrodynamic forces acting on a ship during navigation. This test primarily uses a planar motion mechanism (PMM) to control ship motion, a type of PMM test. Currently, uncertainty analysis for PMM tests primarily utilizes analysis procedures recommended by the International Towing Tank Conference (ITTC) Committee.

[0003] The essence of uncertainty analysis is to quantitatively reflect the sensitivity of test results to uncertainties in the model and test setup through mathematical simulation methods. For PMM tests, the uncertainty analysis process aims to determine the extent to which the test results (i.e., the hydrodynamic forces acting on the ship model) vary due to fluctuations in the uncertainty of input parameters (such as model geometry, speed, PMM motion, and gauge measurements). The current ITTC uncertainty analysis procedure is based on unrestricted water testing and does not consider special conditions such as shallow water and near-shore walls. In addition, the ship model speed in the procedure refers to the trailer speed in the towing tank, while the ship model speed in the circulating water tank refers to the water flow speed.

[0004] Compared with the conventional PMM test, the measurement results of the bank effect hydrodynamic test are smaller and more difficult to measure. The accuracy of the test results should be paid more attention. Therefore, the uncertainty analysis method of ship bank effect hydrodynamics has important application value. Summary of the Invention

[0005] The purpose of the present invention is to propose a method, system and medium for uncertainty analysis of ship bank effect hydrodynamics, so as to solve the limitation of the current uncertainty analysis method of ship model test that does not consider shallow water and bank effect, and realize hydrodynamic uncertainty analysis.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows: On the one hand, a method for uncertainty analysis of ship wall effect hydrodynamics is provided, comprising the following steps: Determine the experimental error sources of the ship wall effect in restricted waters and classify the experimental error sources into ship model processing length deviation, ship model draft deviation, water density deviation, ship model speed deviation and measured hydrodynamic deviation; Establish a functional relationship between the bank-effect hydrodynamics and each experimental error source, obtain the deviation of each experimental error source, and synthesize the deviation limit of the bank-effect hydrodynamics based on the deviations of all experimental error sources; The accuracy limit of the bank effect hydrodynamics is obtained by measuring multiple groups of hydrodynamic values ​​by repeated tests and calculating the mean and standard deviation of the multiple groups of hydrodynamic values ​​and then combining them with the confidence level coefficient. The uncertainty of the ship's shore effect hydrodynamics is obtained according to the deviation limit and the accuracy limit.

[0007] Preferably, establishing a functional relationship between the bank effect hydrodynamics and each experimental error source to obtain the deviation of each experimental error source includes: The deviation between the measured length of the ship model vertical line and the designed length is taken as the ship model processing length deviation. B L , subscript L Indicates the length between perpendicular lines of the ship model; The average value of the deviation between the actual draft height of the bow and stern vertical line of the ship model and the draft height of the drawn waterline is taken as the draft deviation of the ship model. B T , subscript T Indicates the draft of the ship model. The waterline drawn refers to the theoretical waterline drawn on the ship model before the test. Obtain the temperature deviation based on the functional relationship between water density and temperature, and determine the water density deviation based on the temperature deviation B ρ , subscript r Indicates the density of water; A Pitot tube is used to collect the flow velocity at multiple locations in any cross section of the circulating water tank measurement section, and the uncertainty of the deviation between the flow velocity and the set flow velocity at a confidence level of 95% is used as the speed deviation of the ship model. B U , the uncertainty coverage factor is taken as 2, the subscript U Indicates the speed of the ship model; The measured hydrodynamic deviation is obtained based on the measurement deviation of the dynamometer, the measurement process deviation of the dynamometer, the water depth deviation and the ship-shore distance deviation. B F , subscript F Indicates the lateral force of the ship Y and yaw moment N .

[0008] Preferably, the temperature deviation is obtained according to the functional relationship between the density and temperature of water, and the density deviation of water is determined according to the temperature deviation. B ρ include: Get the functional relationship between water density and temperature to get the temperature deviation: ; The density deviation is expressed as temperature deviation: ; Where, r is the density of water, T 0 is the water temperature, B 0 is the measurement deviation of the thermometer.

[0009] Preferably, the hydrodynamic deviation is obtained according to the measurement deviation of the dynamometer, the measurement process deviation of the dynamometer, the water depth deviation and the ship-shore distance deviation. B F include: Calculate and measure hydrodynamic deviations B F The formula is: ; Where, B F1 is the measurement deviation of the dynamometer, B F2 is the measurement process deviation of the dynamometer, B F3 is the water depth deviation, B F4 is the ship-shore distance deviation.

[0010] Preferably, when calculating the measured hydrodynamic deviation, the method further includes: Measurement deviation of the dynamometer B F1 The calculation method is: The force balance of the dynamometer is calibrated using a standard weight. The measurement deviation of the dynamometer is: ( F is the transverse force of the ship); ( F is the yaw moment); Where, m is the number of standard weights used, e i for i The gravity error of the same weight, e g is the gravity error of a single weight, L c is the arm length of the dynamometer, G i for iThe gravity of the same weight, e L is the error in the length of the lever arm; Deviation of the measuring process of the dynamometer B F2 The calculation method is: Select B F1 A force or torque is calibrated during calculation, and the force or torque is repeatedly measured multiple times, and the average value of the difference between the measured value and the calibrated value is calculated. , standard deviation and uncertainty at a 95% confidence level P F , the uncertainty coverage factor is taken as 2, and the maximum value of the measurement deviation is obtained , calculate the maximum value of a group of multiple forces or moments, and fit the linear function between the maximum value and the calibration value by the least squares method to obtain the measurement process deviation of the dynamometer , where A 、 B is the coefficient obtained by fitting, It is the absolute value of the force or torque calibration value; The water depth deviation B F3 The calculation formula is: ; Where, F represents the ship's lateral force Y and yaw moment N, h For water depth, e h is the water depth error, water depth error e h is the uncertainty of the bottom roughness at a confidence level of 95%, and the uncertainty coverage factor is 2; Ship-to-shore distance deviation B F4 The calculation formula is: ; Where, F represents the ship's lateral force Y and yaw moment N, y b is the distance between ship and shore, e yb is the ship-shore distance error, e yb is the installation error of the lateral position of the ship model.

[0011] Preferably, the lateral force and the yaw moment are calculated as follows: Obtain the width of restricted waters when the ship is sailing along a vertical wall W、 water depth h、Ship model draft T、 The ship's breadth B Distance from ship to shore y b , and obtain the dimensionless lateral force coefficient of the ship when the ship model sails at a fixed speed and yaw moment coefficient , construct the following functional relationship expression: ; ; ; in, r is the density of water, L PP is the length between perpendicular lines, T Draft for the ship model, U is the ship model speed, y B is the ship-shore distance variable, B is the ship's moulded breadth, y b is the distance between ship and shore, W is the width of the water area, α 1 、 α 2 、 α 3 、 β 1 、 β 2 and β 3 is the fitting coefficient, which is obtained by fitting the ship's lateral force and yaw moment measured in the experiment; The ship's lateral force or bow moment acting on the ship is calculated according to the functional relationship expression.

[0012] Preferably, the deviation limit of the synthetic bank effect hydrodynamics based on the deviations of all experimental error sources includes: Deviation limit of ship's hydrodynamic force due to bank effect B R The calculation formula is: ; Where, R Represents the dimensionless ship lateral force coefficient Y' or yaw moment coefficient N' , r is the density of water, T is the draft of the ship model, U is the speed of the ship model, F Indicates the ship's transverse force Y and yaw moment N; ; ; ; ; .

[0013] Preferably, the method of measuring multiple groups of hydrodynamic values ​​by repeated testing, calculating the mean and standard deviation of the multiple groups of hydrodynamic values, and then calculating the accuracy limit of the bank effect hydrodynamics in combination with the confidence level coefficient includes: Accuracy limits of bank-effect hydrodynamics P R The calculation formula is: , the accuracy limit P R represents the precision limit at a confidence level of 95%, s is the standard deviation of the dimensionless ship lateral force and yaw moment obtained by repeated measurements in the test, n is the number of repeated experiments, n ≥10.

[0014] Preferably, obtaining the uncertainty of the ship's bank effect hydrodynamics according to the deviation limit and the accuracy limit includes: Uncertainty of hydrodynamic forces due to ship-wall effect U R The calculation formula is: , where B R is the deviation limit, P R is the deviation limit.

[0015] On the other hand, a system for uncertainty analysis of ship bank-effect hydrodynamics is provided, the system comprising: A test error source determination module is used to determine the test error sources of the ship wall effect in restricted waters, and classify the test error sources into ship model processing length deviation, ship model draft deviation, water density deviation, ship model speed deviation and measured hydrodynamic deviation; Deviation limit calculation module, used to establish the functional relationship between the bank effect hydrodynamics and each test error source, obtain the deviation of each test error source, and synthesize the deviation limit of the bank effect hydrodynamics based on the deviations of all test error sources; An accuracy limit calculation module is used to measure multiple groups of hydrodynamic values ​​by repeated tests, calculate the average value and standard deviation of the multiple groups of hydrodynamic values, and then calculate the accuracy limit of the bank effect hydrodynamics in combination with the confidence level coefficient; The uncertainty calculation module is used to obtain the uncertainty of the ship's wall effect hydrodynamics according to the deviation limit and the accuracy limit.

[0016] On the other hand, a computer system is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the uncertainty analysis method of ship wall effect hydrodynamics are implemented.

[0017] On the other hand, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the uncertainty analysis method of the ship wall effect hydrodynamics are implemented.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention classifies the sources of test errors for ships in restricted waters, introduces the influencing factors of water depth and ship-shore distance in the measurement of hydrodynamic deviation, proposes a calculation method for the uncertainty of ship model speed based on a circulating water tank, and establishes a functional relationship between the ship's shore effect hydrodynamics and various sources of test errors. This method can obtain reliable hydrodynamic uncertainty, providing technical support for analyzing the uncertainty of test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a flow chart of a method for uncertainty analysis of ship wall effect hydrodynamics in one embodiment of the present application; Figure 2 This is a distribution diagram of the difference between the actual flow rate and the set flow rate in the measuring area of ​​the circulating water tank in one embodiment of the present application; Figure 3 This is a schematic diagram of a ship quay effect test in restricted waters in one embodiment of the present application; Figure 4 : is a fitted relationship diagram of the dimensionless lateral force coefficient of a ship, the water depth, and the distance between the ship and the shore in one embodiment of the present application; Figure 5 is a fitted relationship diagram of the dimensionless bow moment coefficient of a ship, the water depth, and the distance between the ship and the shore in one embodiment of the present application; Figure 6 This is a structural block diagram of an uncertainty analysis system for ship wall effect hydrodynamics in one embodiment of the present application; Figure 7 It is a diagram of the internal structure of a computer system in one embodiment of the present application. DETAILED DESCRIPTION

[0020] The present invention will be described in detail below in conjunction with the accompanying drawings and examples. Obviously, the embodiments described below are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, those skilled in the art can make similar generalizations without violating the connotation of the present invention, so the present invention is not limited by the following specific embodiments.

[0021] like Figure 1 As shown, the embodiment of the present invention discloses a method for uncertainty analysis of ship wall effect hydrodynamics, comprising the following steps: S1: Determine the experimental error sources of the ship wall effect in restricted waters, and classify the experimental error sources into ship model processing length deviation, ship model draft deviation, water density deviation, ship model speed deviation and measured hydrodynamic deviation; S2: Establish a functional relationship between the bank effect hydrodynamics and each experimental error source, obtain the deviation of each experimental error source, and synthesize the deviation limit of the bank effect hydrodynamics based on the deviations of all experimental error sources; S3: Measure multiple sets of hydrodynamic values ​​using repeated tests, calculate the mean and standard deviation of the multiple sets of hydrodynamic values, and then calculate the accuracy limit of the bank effect hydrodynamics in combination with the confidence level coefficient; S4: Obtain the uncertainty of the ship's shore effect hydrodynamics according to the deviation limit and the accuracy limit.

[0022] In other words, the method includes the following steps: determining the source of test error; calculating the deviation limit of the ship's bank-effect hydrodynamics; calculating the accuracy limit of the ship's bank-effect hydrodynamics; and calculating the uncertainty of the ship's bank-effect hydrodynamics.

[0023] This application classifies the sources of test errors for ships in restricted waters, introduces the influencing factors of water depth and ship-shore distance in the measurement of hydrodynamic deviations, proposes a calculation method for the uncertainty of ship model speed based on a circulating water tank, and establishes a functional relationship between the hydrodynamic force of the ship's shore effect and the various sources of test errors. This method can obtain reliable hydrodynamic uncertainty and provide technical support for analyzing the uncertainty of test results.

[0024] Preferably, establishing a functional relationship between the bank effect hydrodynamics and each experimental error source to obtain the deviation of each experimental error source includes: The deviation between the measured length of the ship model vertical line and the designed length is taken as the ship model processing length deviation. B L , subscript L Indicates the length between the perpendiculars of the ship model; in this embodiment, the deviation between the length between the perpendiculars after the ship model is processed and the designed length is 0.002m; The average value of the deviation between the actual draft height of the bow and stern vertical line of the ship model and the draft height of the drawn waterline is taken as the draft deviation of the ship model. B T , subscript T Indicates the draft of the ship model. The drawn waterline refers to the theoretical waterline drawn on the ship model before the test. In this embodiment, the average height difference between the bow perpendicular and the stern perpendicular of the ship model and the drawn waterline is 0.001m. Obtain the temperature deviation based on the functional relationship between water density and temperature, and determine the water density deviation based on the temperature deviation B ρ , subscript r Indicates the density of water; A Pitot tube is used to collect the flow velocity at multiple locations in any cross section of the circulating water tank measurement section, and the uncertainty of the deviation between the flow velocity and the set flow velocity at a confidence level of 95% is used as the speed deviation of the ship model. B U , the uncertainty coverage factor is taken as 2, the subscript U Indicates the speed of the ship model; The measured hydrodynamic deviation is obtained based on the measurement deviation of the dynamometer, the measurement process deviation of the dynamometer, the water depth deviation and the ship-shore distance deviation. B F , subscript F Indicates the lateral force of the ship Y and yaw moment N .

[0025] When using a Pitot tube to collect flow velocities at multiple locations in any cross section of the circulating water tank measurement section, Figure 2 The deviation between the actual flow rate and the set flow rate in the measurement area of ​​the circulating water tank is shown. The uncertainty of these deviations at a confidence level of 95% is the speed deviation of the ship model. B U , the uncertainty coverage factor is taken as 2; in this embodiment, the flow velocity is set to 0.351m / s, the flow velocity standard deviation of the velocity measurement point is calculated to be 0.0022m / s, and the U95 value is 0.001m / s.

[0026] Preferably, the temperature deviation is obtained according to the functional relationship between the density and temperature of water, and the density deviation of water is determined according to the temperature deviation. B ρ include: Get the functional relationship between water density and temperature to get the temperature deviation: ; The density deviation is expressed as temperature deviation: ; Where, r is the density of water,T 0 is the water temperature, B 0 is the measurement deviation of the thermometer.

[0027] The measurement deviation of the thermometer in this embodiment is 0.1°C, the test water temperature is 12.4°C, and the density deviation is 0.012 kg / m 3 .

[0028] Preferably, the hydrodynamic deviation is obtained according to the measurement deviation of the dynamometer, the measurement process deviation of the dynamometer, the water depth deviation and the ship-shore distance deviation. B F include: Calculate and measure hydrodynamic deviations B F The formula is: ; Where, B F1 is the measurement deviation of the dynamometer, B F2 is the measurement process deviation of the dynamometer, B F3 is the water depth deviation, B F4 is the ship-shore distance deviation.

[0029] Preferably, when calculating the measured hydrodynamic deviation, the method further includes: Measurement deviation of the dynamometer B F1 The calculation method is: The force balance of the dynamometer is calibrated using a standard weight. The measurement deviation of the dynamometer is: ( F is the transverse force of the ship); ( F is the yaw moment); Where, m is the number of standard weights used, e i for i The gravity error of the same weight, e g is the gravity error of a single weight, L c is the arm length of the dynamometer, G i for i The gravity of the same weight, e L is the error in the length of the lever arm; Deviation of the measuring process of the dynamometer B F2 The calculation method is: Select B F1 A force or torque is calibrated during calculation, and the force or torque is repeatedly measured multiple times, and the average value of the difference between the measured value and the calibrated value is calculated. , standard deviation and uncertainty at a 95% confidence level P F , the uncertainty coverage factor is taken as 2, and the maximum value of the measurement deviation is obtained , calculate the maximum value of a group of multiple forces or moments, and fit the linear function between the maximum value and the calibration value by the least squares method to obtain the measurement process deviation of the dynamometer , where A 、 B is the coefficient obtained by fitting, It is the absolute value of the force or torque calibration value; The water depth deviation B F3 The calculation formula is: ; Where, F represents the ship's lateral force Y and yaw moment N, h For water depth, e h is the water depth error, water depth error e h is the uncertainty of the bottom roughness at a confidence level of 95%, and the uncertainty coverage factor is 2; Ship-to-shore distance deviation B F4 The calculation formula is: ; Where, F represents the ship's lateral force Y and yaw moment N, y b is the distance between ship and shore, e yb is the ship-shore distance error, e yb is the installation error of the ship model’s transverse position. The meanings of various parameters in the ship wall effect test are as follows: Figure 3 shown.

[0030] In this embodiment, the mass of a standard weight is 0.1 kg, and the mass tolerance is 5 mg. The gravity error of a single weight is 4.9×10 -5N, the arm length of the dynamometer is 0.455m, and the arm length error is 0.00005m, and the corresponding gravity deviation and moment deviation can be obtained.

[0031] Preferably, the water depth error e h The bottom roughness R f The uncertainty of the value is at a confidence level of 95%; In this embodiment, a series of sample points are evenly set on the bottom of the water, and the range of the sample points covers the movement area of ​​the ship model during the entire test process, and the bottom roughness R f That is, the deviation between the sample point depth and the set depth. By calculating the U95 (95% confidence level) value, the water depth error at different lateral positions can be obtained. e h .

[0032] Preferably, the ship-shore distance error e yb is the installation error of the transverse position of the ship model; in this embodiment, it is the deviation between the actual transverse position of the ship and the set position.

[0033] Preferably, the lateral force and the yaw moment are calculated as follows: Obtain the width of restricted waters when the ship is sailing along a vertical wall W、 water depth h、 Ship model draft T、 The ship's breadth B Distance from ship to shore y b , and obtain the dimensionless lateral force coefficient of the ship when the ship model sails at a fixed speed and yaw moment coefficient , construct the following functional relationship expression: ; ; ; in, r is the density of water, L PP is the length between perpendicular lines, T Draft for the ship model, U is the ship model speed, y B is the ship-shore distance variable, B is the ship's moulded breadth, y b is the distance between ship and shore, W is the width of the water area, α 1 、 α2 、 α 3 、 β 1 、 β 2 and β 3 is the fitting coefficient, which is obtained by fitting the ship's lateral force and yaw moment measured in the experiment; The ship's lateral force or bow moment acting on the ship is calculated according to the functional relationship expression.

[0034] Among them, when fitting the data, a nonlinear optimization algorithm based on the two-dimensional subspace constrained trust region method was used. The fitting function is a three-dimensional surface that depends on the ship-shore distance and the water depth draft ratio, such as Figure 4 and Figure 5 As shown in the figure, the specific values ​​of the fitting coefficients are obtained by fitting, and then the water depth error and the ship-shore distance error can be combined to calculate B F3 and B F4 The numerical value of .

[0035] Preferably, the deviation limit of the synthetic bank effect hydrodynamics based on the deviations of all experimental error sources includes: Deviation limit of ship's hydrodynamic force due to bank effect B R The calculation formula is: ; Where, R Represents the dimensionless ship lateral force coefficient Y' or yaw moment coefficient N' , r is the density of water, T is the draft of the ship model, U is the speed of the ship model, F Indicates the ship's transverse force Y and yaw moment N; ; ; ; ; .

[0036] The calculated deviation limits B L 、 B ρ 、 B T 、 B U 、 B FSubstitute the above formula to calculate the dimensionless ship lateral force Y' and yaw moment N' The deviation limit of the hydrodynamic parameters can be obtained by taking the partial derivatives of the length between perpendiculars, the density of water, the draft of the ship model, the speed of the ship model, and the measured lateral force or bow rolling moment of the ship.

[0037] Preferably, the method of measuring multiple groups of hydrodynamic values ​​by repeated testing, calculating the mean and standard deviation of the multiple groups of hydrodynamic values, and then calculating the accuracy limit of the bank effect hydrodynamics in combination with the confidence level coefficient includes: Accuracy limits of bank-effect hydrodynamics P R The calculation formula is: , the accuracy limit P R represents the precision limit at a confidence level of 95%, s is the standard deviation of the dimensionless ship lateral force and yaw moment obtained by repeated measurements in the test, n is the number of repeated experiments, n ≥10.

[0038] Preferably, obtaining the uncertainty of the ship's bank effect hydrodynamics according to the deviation limit and the accuracy limit includes: Uncertainty of hydrodynamic forces due to ship-wall effect U R The calculation formula is: , where B R is the deviation limit, P R is the deviation limit.

[0039] In one embodiment, Figure 6 As shown, a ship wall effect hydrodynamic uncertainty analysis system 10 is provided, comprising: a test error source determination module 1, a deviation limit calculation module 2, an accuracy limit calculation module 3, and an uncertainty calculation module 4.

[0040] The test error source determination module 1 is used to determine the test error sources of the ship wall effect in restricted waters, and classify the test error sources into ship model processing length deviation, ship model draft deviation, water density deviation, ship model speed deviation and measurement hydrodynamic deviation.

[0041] The deviation limit calculation module 2 is used to establish a functional relationship between the bank effect hydrodynamics and each test error source, obtain the deviation of each test error source, and synthesize the deviation limit of the bank effect hydrodynamics based on the deviations of all test error sources.

[0042] The accuracy limit calculation module 3 is used to measure multiple groups of hydrodynamic values ​​by repeated tests, and calculate the accuracy limit of the bank effect hydrodynamics by calculating the average value and standard deviation of the multiple groups of hydrodynamic values ​​and then combining them with the confidence level coefficient.

[0043] The uncertainty calculation module 4 is used to obtain the uncertainty of the ship's wall effect hydrodynamics according to the deviation limit and the accuracy limit.

[0044] In the uncertainty analysis system of the ship's bank effect hydrodynamics, the sources of test errors for ships in restricted waters were classified, the influencing factors of water depth and ship-shore distance were introduced into the measurement of hydrodynamic deviations, and a calculation method for the uncertainty of ship model speed was proposed based on a circulating water tank. A functional relationship between the ship's bank effect hydrodynamics and the various sources of test errors was established, which can obtain reliable hydrodynamic uncertainty and provide technical support for analyzing the uncertainty of test results.

[0045] The specific definitions of the uncertainty analysis system for ship bank-effect hydrodynamics can be found in the definitions of the uncertainty analysis method for ship bank-effect hydrodynamics above and will not be repeated here. Each module in the aforementioned uncertainty analysis system for ship bank-effect hydrodynamics can be implemented in whole or in part through software, hardware, or a combination thereof. Each of these modules can be embedded in or independent of a processor in a computer system in hardware form, or stored in a computer system memory in software form, allowing the processor to call and execute the corresponding operations of each module.

[0046] In one embodiment, a computer system is provided. The computer system may be a server, and its internal structure diagram may be as follows: Figure 7 As shown. The computer system includes a processor, a memory, a network interface and a database connected via a system bus. The processor of the computer system is used to provide computing and control capabilities. The memory of the computer system includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer system is used to store uncertainty analysis data of the hydrodynamic force of the ship's shore effect. The network interface of the computer system is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, a method for uncertainty analysis of the hydrodynamic force of the ship's shore effect is implemented.

[0047] Those skilled in the art will understand that Figure 7The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer system to which the solution of the present application is applied. The specific computer system may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0048] In one embodiment, a computer system is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the following steps are performed: Determine the experimental error sources of the ship wall effect in restricted waters and classify the experimental error sources into ship model processing length deviation, ship model draft deviation, water density deviation, ship model speed deviation and measured hydrodynamic deviation; Establish a functional relationship between the bank-effect hydrodynamics and each experimental error source, obtain the deviation of each experimental error source, and synthesize the deviation limit of the bank-effect hydrodynamics based on the deviations of all experimental error sources; The accuracy limit of the bank effect hydrodynamics is obtained by measuring multiple groups of hydrodynamic values ​​by repeated tests and calculating the mean and standard deviation of the multiple groups of hydrodynamic values ​​and then combining them with the confidence level coefficient. The uncertainty of the ship's shore effect hydrodynamics is obtained according to the deviation limit and the accuracy limit.

[0049] For the specific limitations on the steps implemented when the processor executes the computer program, please refer to the limitations on the uncertainty analysis method for the ship wall effect hydrodynamics mentioned above, which will not be repeated here.

[0050] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented: Determine the experimental error sources of the ship wall effect in restricted waters and classify the experimental error sources into ship model processing length deviation, ship model draft deviation, water density deviation, ship model speed deviation and measured hydrodynamic deviation; Establish a functional relationship between the bank-effect hydrodynamics and each experimental error source, obtain the deviation of each experimental error source, and synthesize the deviation limit of the bank-effect hydrodynamics based on the deviations of all experimental error sources; The accuracy limit of the bank effect hydrodynamics is obtained by measuring multiple groups of hydrodynamic values ​​by repeated tests and calculating the mean and standard deviation of the multiple groups of hydrodynamic values ​​and then combining them with the confidence level coefficient. The uncertainty of the ship's shore effect hydrodynamics is obtained according to the deviation limit and the accuracy limit.

[0051] Regarding the specific limitations on the steps implemented when the computer program is executed by the processor, please refer to the limitations on the uncertainty analysis method for ship wall effect hydrodynamics mentioned above, which will not be repeated here.

[0052] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0053] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0054] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and such modifications and improvements are intended to fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A method for uncertainty analysis of ship-wall effect hydrodynamics, characterized in that: The following steps are involved: Determine the experimental error sources of the ship wall effect in restricted waters and classify the experimental error sources into ship model processing length deviation, ship model draft deviation, water density deviation, ship model speed deviation and measured hydrodynamic deviation; Establish a functional relationship between the bank-effect hydrodynamics and each experimental error source, obtain the deviation of each experimental error source, and synthesize the deviation limit of the bank-effect hydrodynamics based on the deviations of all experimental error sources; The accuracy limit of the bank effect hydrodynamics is obtained by measuring multiple groups of hydrodynamic values ​​by repeated tests and calculating the mean and standard deviation of the multiple groups of hydrodynamic values ​​and then combining them with the confidence level coefficient. The uncertainty of the ship's shore effect hydrodynamics is obtained according to the deviation limit and the accuracy limit.

2. The uncertainty analysis method of ship wall effect hydrodynamics according to claim 1 is characterized in that: The establishment of a functional relationship between the bank effect hydrodynamics and each experimental error source to obtain the deviation of each experimental error source includes: The deviation between the measured length of the ship model vertical line and the designed length is taken as the ship model processing length deviation. B L , subscript L Indicates the length between perpendicular lines of the ship model; The average of the deviations between the actual draft height of the bow and stern perpendiculars of the ship model and the draft height of the drawn waterline is taken as the draft deviation of the ship model. B T , subscript T Indicates the draft of the ship model. The waterline drawn refers to the theoretical waterline drawn on the ship model before the test. Obtain the temperature deviation based on the functional relationship between water density and temperature, and determine the water density deviation based on the temperature deviation B ρ , subscript ρ Indicates the density of water; A Pitot tube is used to collect the flow velocity at multiple locations in any cross section of the circulating water tank measurement section, and the uncertainty of the deviation between the flow velocity and the set flow velocity at a confidence level of 95% is used as the speed deviation of the ship model. B U , the uncertainty coverage factor is taken as 2, the subscript U Indicates the speed of the ship model; The measured hydrodynamic deviation is obtained based on the measurement deviation of the dynamometer, the measurement process deviation of the dynamometer, the water depth deviation and the ship-shore distance deviation. B F , subscript F Indicates the lateral force of the ship Y and yaw moment N .

3. The uncertainty analysis method of ship wall effect hydrodynamics according to claim 2 is characterized in that: The temperature deviation is obtained according to the functional relationship between the density and temperature of water, and the density deviation of water is determined according to the temperature deviation. B ρ include: Get the functional relationship between water density and temperature to get the temperature deviation: ； The density deviation is expressed as temperature deviation: ； Where, ρ is the density of water, T 0 is the water temperature, B 0 is the measurement deviation of the thermometer.

4. The uncertainty analysis method of ship wall effect hydrodynamics according to claim 2 is characterized in that: The hydrodynamic deviation is obtained according to the measurement deviation of the dynamometer, the measurement process deviation of the dynamometer, the water depth deviation and the ship-shore distance deviation. B F include: Calculate and measure hydrodynamic deviations B F The formula is: ； Where, B F1 is the measurement deviation of the dynamometer, B F2 is the measurement process deviation of the dynamometer, B F3 is the water depth deviation, B F4 is the ship-shore distance deviation.

5. The uncertainty analysis method of ship-wall effect hydrodynamics according to claim 4 is characterized in that: When calculating the measured hydrodynamic deviation, it also includes: Measurement deviation of the dynamometer B F1 The calculation method is: The force balance of the dynamometer is calibrated using a standard weight. The measurement deviation of the dynamometer is: ( F is the transverse force of the ship); ( F is the yaw moment); Where, m is the number of standard weights used, ε i for i The gravity error of the same weight, ε g is the gravity error of a single weight, L c is the arm length of the dynamometer, G i for i The gravity of the same weight, ε L is the error in the length of the lever arm; Deviation of the measuring process of the dynamometer B F2 The calculation method is: Select B F1 A force or torque is calibrated during calculation, and the force or torque is repeatedly measured multiple times, and the average value of the difference between the measured value and the calibrated value is calculated. , standard deviation and uncertainty at a 95% confidence level P F , the uncertainty coverage factor is taken as 2, and the maximum value of the measurement deviation is obtained , calculate the maximum value of a group of multiple forces or moments, and fit the linear function between the maximum value and the calibration value by the least squares method to obtain the measurement process deviation of the dynamometer , where A 、 B is the coefficient obtained by fitting, It is the absolute value of the force or torque calibration value; The water depth deviation B F3 and B F4 The calculation formula is: ； Where, F Indicates the ship's lateral force Y and yaw moment N, h For water depth, ε h is the water depth error, water depth error ε h is the uncertainty of the bottom roughness at a confidence level of 95%, and the uncertainty coverage factor is 2; Ship-to-shore distance deviation B F4 The calculation formula is: ； Where, F Indicates the ship's lateral force Y and yaw moment N, y b is the distance between ship and shore, ε yb is the ship-shore distance error, ε yb is the installation error of the lateral position of the ship model.

6. The uncertainty analysis method of ship wall effect hydrodynamics according to claim 5 is characterized in that: The lateral force and the yaw moment are calculated as follows: Obtain the width of restricted waters when the ship is sailing along a vertical wall W、 water depth h、 Ship model draft T、 The ship's breadth B Distance from ship to shore y b , and obtain the dimensionless lateral force coefficient of the ship when the ship model sails at a fixed speed Y' and yaw moment coefficient N' , construct the following functional relationship expression: ； ； ； in, ρ is the density of water, L PP is the length between perpendicular lines, T Draft for the ship model, U is the ship model speed, y B is the ship-shore distance variable, B is the ship's moulded breadth, y b is the distance between ship and shore, W is the width of the water area, α 1 、 α 2 、 α 3 、 β 1 、 β 2 and β 3 is the fitting coefficient, which is obtained by fitting the ship's lateral force and yaw moment measured in the experiment; The ship's lateral force or bow moment acting on the ship is calculated according to the functional relationship expression.

7. The uncertainty analysis method of ship wall effect hydrodynamics according to claim 2 is characterized in that: The deviation limits of the synthetic bank effect hydrodynamics based on the deviations of all experimental error sources include: Deviation limit of ship's hydrodynamic force due to bank effect B R The calculation formula is: ； Where, R Represents the dimensionless ship lateral force coefficient Y' or yaw moment coefficient N' , ρ is the density of water, T is the draft of the ship model, U is the speed of the ship model, F Indicates the ship's transverse force Y and yaw moment N; ； ； ； ； 。 8. The uncertainty analysis method of ship wall effect hydrodynamics according to claim 1 is characterized in that: The accuracy limits of the bank effect hydrodynamics obtained by measuring multiple groups of hydrodynamic values ​​by repeated testing and calculating the mean and standard deviation of the multiple groups of hydrodynamic values ​​and then combining them with the confidence level coefficient include: Accuracy limits of bank-effect hydrodynamics P R The calculation formula is: , the accuracy limit P R represents the precision limit at a confidence level of 95%, σ is the standard deviation of the dimensionless ship lateral force and yaw moment obtained by repeated measurements in the test, n is the number of repeated experiments, n ≥10.

9. The uncertainty analysis method of ship wall effect hydrodynamics according to claim 1 is characterized in that: The uncertainty of obtaining the ship's wall effect hydrodynamic force according to the deviation limit and the accuracy limit includes: Uncertainty of hydrodynamic forces due to ship-wall effect U R The calculation formula is: , where B R is the deviation limit, P R is the deviation limit.

10. An uncertainty analysis system for ship wall effect hydrodynamics, characterized by: The uncertainty analysis system of ship wall effect hydrodynamics includes: A test error source determination module is used to determine the test error sources of the ship wall effect in restricted waters, and classify the test error sources into ship model processing length deviation, ship model draft deviation, water density deviation, ship model speed deviation and measured hydrodynamic deviation; Deviation limit calculation module, used to establish the functional relationship between the bank effect hydrodynamics and each test error source, obtain the deviation of each test error source, and synthesize the deviation limit of the bank effect hydrodynamics based on the deviations of all test error sources; An accuracy limit calculation module is used to measure multiple groups of hydrodynamic values ​​by repeated tests, calculate the average value and standard deviation of the multiple groups of hydrodynamic values, and then calculate the accuracy limit of the bank effect hydrodynamics in combination with the confidence level coefficient; The uncertainty calculation module is used to obtain the uncertainty of the ship's wall effect hydrodynamics according to the deviation limit and the accuracy limit.

11. A computer system comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 9 are implemented.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 9 are implemented.

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