Method for determining effective power of representative ship type in waterway regulation design

Abstract

The present application relates to the technical field of waterway regulation design, and particularly relates to a method for determining effective power of a representative ship type in waterway regulation design, comprising the following steps: obtaining waterway information of a target waterway and determining corresponding design representative ship type scale parameters; determining minimum static water speed of the representative ship type under maximum continuous power according to current statutory ship regulations; and determining standardized effective power of the representative ship type for waterway regulation design by a specification regression method based on the minimum static water speed and the representative ship type scale parameters. The present application has clear parameter interfaces, unified calculation caliber, and can convert the statutory minimum speed and the regression method into standardized effective power of the representative ship type in waterway design, and can determine repeatable and traceable standardized effective power of the representative ship type in waterway design.

Description

Technical Field

[0001] This invention relates to the field of waterway improvement design technology, and specifically to a method for determining the effective power of representative ship types in waterway improvement design. Background Technology

[0002] The design of rapids and shoals in mountainous waterways typically requires selecting an existing ship resistance calculation method that is suitable for the specific conditions of the waterway to be improved, based on the dynamic performance of the representative ship type. By establishing a thrust-balance relationship, the control velocity-ramp combination for ships to enter the rapids is determined as the target hydraulic index for shoal reduction in the waterway improvement design. This is used to verify and evaluate whether the design scheme can meet the requirements for ships to enter the rapids after implementation.

[0003] Currently, various methods exist for calculating ship resistance, but there is no unified standard method for determining the dynamic performance of representative design vessels. In past waterway improvement projects, traditional methods for determining dynamic performance often directly used the rated power of the main engines of existing operational vessels or historical engineering experience values. Due to differences in ship age, loading conditions, propulsion efficiency, engine-propeller matching, and modifications, the main engine power of actual ships of the same tonnage exhibits significant dispersion. Directly using data from individual ships that are too low or too high as the design standard can easily lead to distorted judgments of navigation capacity, further affecting the amount of dredging, reef blasting, dam construction, and other improvement works, as well as ecological and flood control impacts. On the other hand, the main dimensions of existing vessel types often differ from the main dimensions of the representative design vessel type determined according to waterway engineering design standards, resulting in a mismatch between the vessel type used for calculating shoal reduction hydraulic indicators and the representative design vessel type.

[0004] Although legal regulations for ships have specified the minimum speeds that vessels in different waterways, navigation areas, or sections should achieve under maximum continuous power conditions from the perspective of ship safety and maneuverability, and have provided representative ship dimensions, displacement, and speed-effective power regression calculation methods, these regulations are mainly used for ship construction and inspection. The existing waterway improvement design process lacks a method with clearly defined parameter interfaces, unified calculation methods, and the ability to convert the aforementioned legally mandated minimum speeds and regression methods into standardized effective power for representative ship types in waterway design. Summary of the Invention

[0005] To address the technical problem that existing methods for obtaining the relationship between the speed and power of specific ships rely on actual ships, hull lines, or test data, making it difficult to provide a standardized and traceable effective power for representative ship types in different waterway improvement projects, this invention provides a method for determining the effective power of representative ship types in waterway improvement design. This method can determine a standardized and traceable effective power for representative ship types in waterway design.

[0006] This invention is achieved through the following technical solution:

[0007] This invention provides a method for determining the effective power of a representative ship type in waterway improvement design, comprising the following steps:

[0008] Obtain the waterway information of the target waterway and determine the corresponding design representative ship size parameters;

[0009] The minimum still water speed for a representative ship type at maximum continuous power is determined in accordance with current ship regulations.

[0010] Based on the minimum still water speed and the representative ship type dimensional parameters, the standardized effective power of the representative ship type for use in waterway improvement design is determined by a normative regression method.

[0011] Specifically, the waterway information includes waterway grade, water system identification, representative vessel type, representative vessel deadweight tonnage, and navigation area / section identification.

[0012] Specifically, the representative ship dimensional parameters include the length between perpendiculars. Waterline length , width Design draft Square coefficient Number of propellers and drainage volume .

[0013] Specifically, the displacement is determined based on hydrostatic data of a representative ship type or based on a displacement estimation model;

[0014] The displacement estimation model is as follows: In the formula, the density of fresh water is... Pick Alternatively, the actual density of the water body in the project can be obtained.

[0015] Specifically, the determination of the representative ship type dimensional parameters is based on at least one of the following: waterway engineering technical standards, standard ship type main dimension series, or project design documents that have been reviewed and confirmed.

[0016] Specifically, the method for determining the minimum still water speed of a representative ship type at maximum continuous power, based on current ship regulations, includes the following steps:

[0017] Based on current ship regulations and waterway markings Flight area and segment markings Based on the ship type, determine the minimum still water speed limit for the ship under maximum continuous power conditions. (Unit: km / h);

[0018] Establish a regulatory mapping table. If the same target route is subject to multiple minimum speed clauses, select the limit with the highest requirement and the most direct scope of application. If the current legal regulations for ships provide a speed range, select the lower limit of the range as the standardized calculation speed.

[0019] Minimum still water speed limit Convert the units to m / s to get , This is the legally mandated minimum speed for still water navigation.

[0020] Specifically, based on the minimum still water speed and the representative ship type dimensional parameters, the method for determining the standardized effective power of the representative ship type for use in waterway improvement design through normative regression includes the following steps:

[0021] The legal minimum speed in still water The speed V used in the normalized regression calculation is used to calculate the Froude number. And ship length and displacement parameters ;

[0022] According to Fu Rude The horizontal axis represents the ship's length and displacement parameters. For curve parameters, in the basic coefficients Find the fundamental coefficients in the graph. ;

[0023] Based on the number of propellers Calculate and determine the critical square coefficient ;

[0024] Based on the square coefficient and critical square coefficient Calculate parameter t;

[0025] Based on square coefficient and critical square coefficient Relationship, calculation parameters ;

[0026] According to parameters Sum of coefficients Calculate coefficients ;

[0027] Calculation coefficient based on wide draft ratio ;

[0028] Based on coefficients Sum of coefficients Calculate the correction factor ;

[0029] Based on the length between perpendiculars and waterline length Calculate coefficients ;

[0030] Based on coefficients Calculate the statutory minimum still water speed according to the branch of the water system. Standardized effective power .

[0031] In an optional embodiment of this application, after determining the standardized effective power of the representative ship type, the rationality of the main engine power of the standardized effective power of the representative ship type is checked.

[0032] Specifically, the method for verifying the rationality of the main engine power of the standardized effective power of the representative ship type includes the following steps:

[0033] Select the overall propulsion factor within the range recommended by test and design data or specifications for similar ship types. ;

[0034] Based on standardized effective power and total propulsion coefficient Computer host rated power ;

[0035] Collect data on the rated power of main engines of newly built vessels of the same tonnage in recent years in the local area or similar navigation sections of the same waterway, compare them with the calculated data, and verify their rationality.

[0036] In an optional embodiment of this application, after determining the standardized effective power of the representative ship type, the effective thrust of the design representative ship type is calculated based on the standardized effective power of the design representative ship type.

[0037] Specifically, the method for calculating the effective thrust of a representative ship type based on the standardized effective power of the representative ship type includes the following steps:

[0038] For the i-th test case of rapid flow, read the water flow velocity. and ship speed above ground Determine the ship's speed relative to the water. ;

[0039] The formula for calculating a ship's speed over water is:

[0040] The available effective thrust for the i-th operating condition The computational model is ,in, To represent the standardized effective power of the ship type, Let be the ship's speed relative to water at the i-th operating point. With kW, Timed in m / s, The numerical unit is kN.

[0041] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0042] 1. The method for determining the effective power of representative ship types in waterway improvement design provided by the present invention uses the representative ship types corresponding to the waterway grade and the statutory minimum speed as unified constraints, which reduces the sample dispersion caused by ship age, aircraft type and operating status, and makes the power of representative ship types in different projects comparable.

[0043] 2. The method for determining the effective power of representative ship types in waterway improvement design provided by this invention converts the minimum speed constraints and effective power regression methods in shipbuilding regulations into a unified power input for representative ship types in waterway improvement design, without relying on the existence of a sufficient number of actual ship samples of the same tonnage in the target waterway section.

[0044] 3. The method for determining the effective power of representative ship types in waterway improvement design provided by this invention uses regression calculation correction branches and intermediate quantities to locate whether the difference comes from ship type parameters, navigation area speed clauses, or map lookup values, thereby improving the efficiency of verification.

[0045] 4. The method for determining the effective power of representative ship types in channel regulation design provided by this invention standardizes the effective power and can be connected with different existing resistance calculation methods. The core power determination caliber will not change due to the change of resistance model for specific projects, which helps to reduce the risk of over-regulation caused by underestimating the power value. Attached Figure Description

[0046] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0047] In the attached diagram:

[0048] Figure 1 A flowchart illustrating the method for determining the effective power of a representative ship type in waterway improvement design, as provided in an embodiment of the present invention.

[0049] Figure 2 A data relationship diagram related to the method for determining the effective power of a representative ship type in waterway improvement design provided in an embodiment of the present invention;

[0050] Figure 3 The basic coefficients used in the method for determining the effective power of representative ship types in waterway improvement design provided in the embodiments of the present invention Look up the graph. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0052] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples.

[0053] Example

[0054] Combination Figure 1 This embodiment provides a method for determining the effective power of a representative ship type in waterway improvement design, including the following steps:

[0055] S10. Obtain the channel information of the target channel and determine the corresponding design representative ship type dimensional parameters.

[0056] Specifically, the waterway information includes waterway grade, waterway markings, representative vessel type, representative vessel deadweight tonnage, and navigation area / section markings; the representative vessel dimensional parameters include length between perpendiculars. Waterline length , width Design draft Square coefficient Number of propellers and drainage volume .

[0057] The representative ship type dimensional parameters are determined based on at least one of the following: waterway engineering technical standards, standard ship type main dimension series, or reviewed and confirmed project design documents. The displacement is determined based on the representative ship type's hydrostatic data or a displacement estimation model; the displacement estimation model is... In the formula, the density of fresh water is... Pick Alternatively, the actual density of the water body in the project can be obtained.

[0058] More specifically, S10 includes the following steps:

[0059] S11. Read the planned or designed channel grade, waterway system, and the representative ship type and deadweight tonnage class to be used for the target waterway. According to the China Maritime Safety Administration's "Navigation Area Division Rules (2021)," determine the navigation area and section of the target waterway. The channel grade is used to determine the representative ship type, and the waterway system and navigation area / section are used for subsequent minimum speed and regression formula branch selection.

[0060] S12. Determine the length between perpendiculars of the representative ship type according to current waterway engineering technical standards, standard ship type main dimension series, or reviewed and confirmed project design documents. Waterline length , width Design draft Square coefficient and number of propellers .

[0061] When the standard only provides a range of ship lengths, the value specified for the design ship type shall be used first; when there is no specified value, the standard value corresponding to the target tonnage shall be used, and the basis for selection shall be recorded.

[0062] S13. Determine the drainage volume If hydrostatic data for a representative ship type is available, the displacement under calculation conditions can be directly read; if hydrostatic data is unavailable, it can be estimated using the following formula: In the formula, the density of fresh water is... Pick Alternatively, the actual density of the water body in the project can be obtained.

[0063] If the square coefficient is defined using the length between perpendicular lines Therefore, the calculation of drainage volume should adopt the corresponding method. And ensure consistency with the definitions of subsequent spectra and correction formulas.

[0064] S14. Perform a consistency check on the input: the length is uniformly set to m, and the displacement is uniformly set to t; , , and It must not be empty; the squareness factor, displacement, and principal dimensions should correspond to the same loading condition.

[0065] Thus, a parameter set is formed. ,in For water system identification, This serves as the identification for flight areas / segments, and is used as input for subsequent S20 and S30.

[0066] S20. Determine the minimum still water speed of the representative ship type at maximum continuous power in accordance with current ship regulations.

[0067] Specifically, step S20 includes the following steps:

[0068] S21. In accordance with current ship regulations and based on waterway markings Flight area and segment markings Based on the ship type, determine the minimum still water speed limit for the ship under maximum continuous power conditions. That is, based on the water system identifier, navigation area / segment identifier and vessel type category in the parameter set, and in accordance with Articles 10.3.1.4 and 10.3.1.5 of the "Technical Rules for Statutory Inspection of Inland Waterway Vessels (Revised and Notified in 2023)" issued by the China Maritime Safety Administration, the minimum still water speed limit of the vessel under the maximum continuous power condition is obtained.

[0069] S22. Establish a regulatory mapping table. If the same target route is subject to multiple minimum speed clauses, select the limit with the highest requirement and the most direct scope of application. If the current legal regulations for ships provide a speed range, select the lower limit of the range as the standardized calculation speed.

[0070] Taking the applicable rules as an example, the minimum speed limits for the J1 and J2 sections of the Yangtze River system, other waterways, and the Beijing-Hangzhou Grand Canal or the Pearl River system are 20.7 km / h, 18.0 km / h, 14.8 km / h, and 12.0 km / h, respectively; for other waterways, the limits shall be determined according to the applicable rules or relevant clauses.

[0071] If the same target flight segment is subject to multiple minimum speed clauses, select the limit with the highest requirement and the most direct applicability; if the specification provides a speed range, select the lower limit of the range as the standardized calculation speed. Record the rule name, version, clause number, applicable objects, and selection results to ensure traceability of the calculation.

[0072] S23, Minimum Still Water Speed ​​Limit Convert the units to m / s to get , This is the legally mandated minimum speed for navigation in still water. That is, the limit is converted from km / h to m / s: Output the legally mandated minimum still water speed Records of legal basis.

[0073] It should be noted that here It is the power calibration speed in the subsequent step S30, and is not directly equivalent to the ground speed or relative water flow speed in the subsequent optional engineering verification.

[0074] S30. Based on the minimum still water speed and the representative ship type dimensional parameters, determine the standardized effective power of the representative ship type for use in waterway improvement design through a standardized regression method (the method is from the "Implementation Guidelines for Energy Efficiency Design Index (EEDI) of New Inland Waterway Vessels"). That is, the minimum effective power required for the design of the representative ship type with given ship type parameters to meet the statutory minimum still water speed requirement.

[0075] Specifically, step S30 includes the following steps:

[0076] S31, The legally mandated minimum still water speed The speed V used in the normalized regression calculation is used to calculate the Froude number. And ship length and displacement parameters That is, let Calculate the Froude number and the ship's length and displacement parameters: ,in .

[0077] S32, based on Fu Rude's number The horizontal axis represents the ship's length and displacement parameters. For curve parameters, in the basic coefficients Find the fundamental coefficients in the graph. (The graph is from the "Implementation Guidelines for Energy Efficiency Design Index (EEDI) of Newly Built Inland Waterway Vessels").

[0078] Specifically, with x-axis For curve parameters, in the basic coefficients Searching for in the map When the calculation point is located between adjacent curves or adjacent grids, linear interpolation is used, and adjacent nodes and interpolation results are saved; when the calculation point is outside the applicable range of the map, no unfounded extrapolation is performed, but instead a verified alternative speed-power method is suggested to be used.

[0079] S33, Based on the number of propellers Calculate and determine the critical square coefficient Specifically, single-propeller ships meet the requirements. Twin-propeller boats meet .

[0080] S34, Based on the square coefficient and critical square coefficient Calculate parameter t; based on square coefficient and critical square coefficient The relationship between the parameter t and the parameter value, and the calculation of the parameter. According to parameters Sum of coefficients Calculate coefficients .

[0081] Specifically:

[0082]

[0083] when hour, If the calculation result is less than -10, then let .

[0084] when and hour, ;

[0085] when and season .

[0086] Final calculation .

[0087] S35. Calculate the coefficient based on the wide draft ratio. ,in:

[0088] when hour, ;when hour, .

[0089] For vessels on the Beijing-Hangzhou Grand Canal or the Pearl River system, when and At that time, adopt .

[0090] S36, Based on the wide draft ratio correction coefficient Calculate the ship type correction factor That is, based on coefficients Sum of coefficients Calculate the correction factor And based on the length between perpendiculars and waterline length Calculate coefficients Specifically:

[0091] when hour, ;

[0092] when hour, ;

[0093] Then corrected according to the waterline length. .

[0094] in, Based on and combined ship type correction factors.

[0095] S37. Calculate the statutory minimum still water speed based on the hull type correction factor and according to the waterway branch. Standardized effective power under the given conditions, i.e., based on coefficients Calculate the statutory minimum still water speed according to the branch of the water system. Standardized effective power .

[0096] Specifically, vessels in the Yangtze River system adopt... Vessels on the Beijing-Hangzhou Grand Canal or the Pearl River system adopt ,in The unit is kW. The unit is t. The unit is m / s, and the speed index in this formula is 3.

[0097] Then, output the representative ship type's standardized effective power for waterway improvement design. And save intermediate values The source of its parameters is used for calculation and traceability. This completes the process of determining the effective power standardization.

[0098] Optionally, in Repeat steps S31-S37 at at least 8 nearby speed points to form an effective power curve and verify it. It increases monotonically with overall speed; when used for single-point standardization determination, at least the power point corresponding to the statutory minimum speed should be calculated.

[0099] S40. Main engine power rationality verification and propulsion capacity calculation: that is, after determining the standardized effective power of the representative ship type, the main engine power rationality verification is performed on the standardized effective power of the representative ship type, and the propulsion capacity is calculated.

[0100] Specifically, S40 includes the following steps:

[0101] S41. After determining the standardized effective power of the representative ship type, based on the overall propulsion coefficient... Range calculation host rated power By comparing the power parameters of newly built ships in recent years, the rationality of standardized effective power is analyzed.

[0102] Specifically, the method for verifying the rationality of the main engine power of the standardized effective power of the representative ship type includes the following steps:

[0103] Select the overall propulsion factor within the range recommended by test and design data or specifications for similar ship types. ;

[0104] Based on standardized effective power and total propulsion coefficient Computer host rated power Main unit power verification value The calculation model is , ;

[0105] Collect data on the rated power of main engines of newly built vessels of the same tonnage in recent years in the local area or similar navigation sections of the same waterway, compare them with the calculated data, and verify their rationality.

[0106] Therefore, the host power verification value is verified. To determine whether the calculated effective power is reasonable, we need to compare the main engine power values ​​of newly built vessels of the same tonnage in the same area or similar waterways with those of similar vessels built in recent years.

[0107] S42. After determining the standardized effective power of the representative ship type, calculate the effective thrust of the design representative ship type based on the standardized effective power of the design representative ship type.

[0108] Specifically, the method for calculating the effective thrust of a representative ship type based on the standardized effective power of the representative ship type includes the following steps:

[0109] For the i-th test case of rapid flow, read the water flow velocity. and ship speed above ground Determine the ship's speed relative to the water. .

[0110] Among them, the formula for calculating the ship's speed relative to the water flow under the upstream condition is: If the opposite direction sign convention is adopted, then the magnitude of the velocity vector difference will be used uniformly. All operating conditions should use the same symbol convention, and .

[0111] Convert the standardized effective power of the representative ship type into the available effective thrust for the i-th operating condition. .

[0112] In this embodiment, the available effective thrust for the i-th operating condition The calculation model is ,in, To adopt the representative ship type standardized effective power obtained in step S30, Let be the ship's speed relative to water at the i-th operating point. With kW, Timed in m / s, The numerical unit is kN.

[0113] To avoid an unreasonable increase in thrust due to constant power in the low-speed region, a minimum effective relative speed can be set. ,exist The verified propeller thrust upper limit is used; for upstream conditions, the solution is preferably obtained in the speed range near and above the legal minimum speed.

[0114] Based on the above steps, this embodiment provides a method for determining the hydraulic indicators for shoal reduction in a specific waterway improvement project, including the following steps:

[0115] S51. The water depth, channel dimensions, current velocity, water surface gradient, ship relative speed to the current, and representative ship dimensional parameters of the navigation section are used to select a method suitable for the target operating condition from existing methods for determining ship resistance, thereby obtaining the navigation resistance or required effective power under the corresponding operating condition. The existing methods for determining ship resistance can be calculation methods specified in waterway engineering codes, empirical or semi-empirical formulas, numerical simulation methods, model test methods, full-ship test methods, or combinations of the above methods; for example, when applicable conditions are met, the Zvankov formula recommended in the *Waterway Engineering Handbook* can be used.

[0116] S52. Establish a data interface between the standardized effective power output in step S30 and the selected existing resistance determination method.

[0117] When the selected method outputs the navigation resistance, it can be converted into the required effective power by combining the relative water flow speed, or compared with the available propulsion obtained in step S40; when the selected method directly outputs the required effective power, it is compared with the standardized effective power output in step S30. As long as the input and output dimensions are consistent, it is not limited by the resistance model.

[0118] S53. Based on the comparison results, determine the representative ship type's shoal-reduction hydraulic index or shoal-entry index under the target operating conditions, and accordingly form the velocity limit, gradient limit, velocity-gradient combination boundary, or other channel regulation design judgment results. When shallow water, narrow channels, bank walls, or safety margins need to be considered in the project, appropriate modifications should be added according to the applicable conditions of the selected existing methods.

[0119] Understandably, the sailing resistance can be decomposed into hull water resistance and additional resistance caused by water surface gradient. Existing design methods can be used to determine each resistance component separately, and then the required propulsion capacity can be compared with the standardized effective power obtained in step S30.

[0120] This embodiment uses a Class III waterway on the Jinsha River in the Yangtze River system and a representative 1000t bulk carrier as an example to illustrate the specific calculations, as follows:

[0121] First, determine the representative ship size parameters based on the waterway grade: , , , , , The waterline length is determined based on the project's vessel type data, ensuring the accuracy of subsequent calculations. Consistent with ship type information.

[0122] Secondly, since the target section belongs to the J1 category of the Yangtze River system, the minimum speed is taken as 20.7 km / h according to applicable legal rules, and the result is... And calculated based on the above records. , ; obtained from image search Among them, the twin-sprocket boat , Take from the limit ,get .Depend on, , ,get After correction for waterline length, it was obtained At the same time, the Yangtze River system formula is adopted. To obtain the effective power of representative ship types .

[0123] Then, take the overall propulsion coefficient of a similar ship type. ,but

[0124] This is close to the rated power of the main engine of a relatively new 1000t-class vessel in the area, which is 1060kW. For a given rapid current condition, according to... Calculate the relative water flow speed, and then... A usable effective thrust is obtained.

[0125] It should be noted that in engineering applications, existing ship resistance calculation methods, numerical simulation methods, model test methods, or full-scale ship test methods can be selected according to the conditions of the target navigation segment. When applicable conditions are met, the Zvankov formula recommended in the "Handbook of Waterway Engineering" can be used. The required propulsion capacity calculated by the selected method should be compared with the standardized effective power.

[0126] In addition, in the engineering application of this embodiment in a certain rapid section of the waterway, the control current speed of the rapid was increased from about 3.4 m / s corresponding to historically low-powered ships to about 4.5 m / s, indicating that the effective power of the representative ship type determined in this embodiment can reduce the excessive regulation caused by the low power of the sample ship.

[0127] In summary, the method for determining the effective power of representative vessel types in channel improvement design provided in this embodiment uses the representative vessel type corresponding to the channel grade and the statutory minimum speed as unified constraints, reducing sample dispersion caused by vessel age, aircraft type, and operational status, and making the power of representative vessel types in different projects comparable. It transforms the minimum speed constraint and effective power regression method in shipbuilding regulations into a unified power input for representative vessel types in channel improvement design, without relying on the existence of a sufficient number of actual vessel samples of the same tonnage in the target channel. By using the correction branch and intermediate quantity of regression calculation, it can locate whether the difference comes from vessel type parameters, navigation area speed clauses, or map lookup values, improving the efficiency of verification. The standardized effective power can be connected with different existing resistance calculation methods, and the core power determination caliber will not change due to the change of resistance model for specific projects, which helps to reduce the risk of over-improvement caused by underestimating the power value.

[0128] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for determining the effective power of a representative ship type in waterway improvement design, characterized in that, Includes the following steps: Obtain the waterway information of the target waterway and determine the corresponding design representative ship size parameters; The minimum still water speed for a representative ship type at maximum continuous power is determined in accordance with current ship regulations. Based on the minimum still water speed and the representative ship type dimensional parameters, the standardized effective power of the representative ship type for use in waterway improvement design is determined by a normative regression method.

2. The method for determining the effective power of representative ship types in waterway improvement design according to claim 1, characterized in that, The waterway information includes waterway grade, water system identification, representative ship type, representative ship deadweight tonnage, and navigation area / section identification.

3. The method for determining the effective power of representative ship types in waterway improvement design according to claim 2, characterized in that, The representative ship type dimensional parameters include the length between perpendiculars. Waterline length , width Design draft Square coefficient Number of propellers and drainage volume .

4. The method for determining the effective power of representative ship types in waterway improvement design according to claim 3, characterized in that, The displacement is determined based on hydrostatic data of a representative ship type or based on a displacement estimation model. The displacement estimation model is as follows: In the formula, the density of fresh water is... Pick Alternatively, the actual density of the water body in the project can be obtained.

5. The method for determining the effective power of representative ship types in waterway improvement design according to claim 2, characterized in that, The determination of the representative ship type dimensional parameters is based on at least one of the following: waterway engineering technical standards, standard ship type main dimension series, or project design documents that have been reviewed and confirmed.

6. The method for determining the effective power of representative ship types in waterway improvement design according to claim 2, characterized in that, The method for determining the minimum still water speed of a representative ship type at maximum continuous power, based on current ship regulations, includes the following steps: Based on current ship regulations and waterway markings Flight area and segment markings Based on the ship type, determine the minimum still water speed limit for the ship under maximum continuous power conditions. Unit: km / h; Establish a regulatory mapping table. If the same target route is subject to multiple minimum speed clauses, select the limit with the highest requirement and the most direct scope of application. If the current legal regulations for ships provide a speed range, select the lower limit of the range as the standardized calculation speed. Minimum still water speed limit Convert the units to m / s to get , This is the legally mandated minimum speed for still water navigation.

7. The method for determining the effective power of representative ship types in waterway improvement design according to claim 6, characterized in that, Based on the minimum still water speed and the representative ship type dimensional parameters, the method for determining the standardized effective power of the representative ship type for use in waterway improvement design through normative regression includes the following steps: The legal minimum speed in still water The speed V used in the normalized regression calculation is used to calculate the Froude number. And ship length and displacement parameters ; According to Fu Rude The horizontal axis represents the ship's length and displacement parameters. For curve parameters, in the basic coefficients Find the fundamental coefficients in the graph. ; Based on the number of propellers Calculate and determine the critical square coefficient ; Based on the square coefficient and critical square coefficient Calculate parameter t; Based on square coefficient and critical square coefficient Relationship, calculation parameters ; According to parameters Sum of coefficients Calculate coefficients ; Calculation coefficient based on wide draft ratio ; Based on coefficients Sum of coefficients Calculate the correction factor ; Based on the length between perpendiculars and waterline length Calculate coefficients ; Based on coefficients Calculate the statutory minimum still water speed according to the branch of the water system. Standardized effective power .

8. The method for determining the effective power of representative ship types in waterway improvement design according to any one of claims 1 to 7, characterized in that, After determining the standardized effective power of the representative ship type, the rationality of the main engine power of the standardized effective power of the representative ship type is checked.

9. The method for determining the effective power of representative ship types in waterway improvement design according to claim 8, characterized in that, The method for verifying the rationality of main engine power for the standardized effective power of the representative ship type includes the following steps: Select the overall propulsion factor within the range recommended by test and design data or specifications for similar ship types. ; Based on standardized effective power and total propulsion coefficient Computer host rated power ; Collect data on the rated power of main engines of newly built vessels of the same tonnage in recent years in the local area or similar navigation sections of the same waterway, compare them with the calculated data, and verify their rationality.

10. The method for determining the effective power of representative ship types in waterway improvement design according to any one of claims 1 to 7, characterized in that, After determining the standardized effective power of the representative ship type, the effective thrust of the design representative ship type is calculated based on the standardized effective power of the design representative ship type.

11. The method for determining the effective power of representative ship types in waterway improvement design according to claim 10, characterized in that, The method for calculating the effective thrust of a representative ship type based on the standardized effective power of the representative ship type includes the following steps: For the i-th test case of rapid flow, read the water flow velocity. and ship speed above ground Determine the ship's speed relative to the water. ; The formula for calculating a ship's speed over water is: ; The available effective thrust for the i-th operating condition The calculation model is ,in, To represent the standardized effective power of the ship type, Let be the ship's speed relative to water at the i-th operating point. With kW, Timed in m / s, The numerical unit is kN.

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