Method and system for analyzing sailing safety by ship wake flow in navigable tunnel

Abstract

The invention provides a method and system for analyzing navigation safety by ship wake flow in a navigation tunnel, and belongs to the technical field of navigation safety. The method comprises the following steps: firstly, acquiring basic data for ship wake flow analysis in a navigable tunnel, then calculating an initial ship wake flow wave height based on a driving speed, a ship width and a draft depth, calculating a navigable tunnel influence factor based on a section diameter and the ship width, and calculating a Kelvin wake flow item KT based on the section diameter and the ship width; and finally, based on the initial ship wake flow wave height, the navigable tunnel influence factor and the kelvin wake flow item, calculating a final ship wake flow wave height, and carrying out navigation safety analysis. When the ship wake flow wave height is calculated, the section and the ship type of the navigable tunnel are comprehensively considered, compared with the prior art, the completeness of a physical analysis model of the ship wake flow wave height in the navigable tunnel can be improved, and the accuracy of a wave height analysis result is objectively improved.

Description

Technical Field

[0001] This invention belongs to the field of shipping safety technology, and in particular relates to a method and system for analyzing the impact of ship wake on navigation safety in navigation tunnels. Background Technology

[0002] Navigation tunnels are engineering facilities used in shipping to traverse mountains or complex terrain, shortening voyages and meeting the requirements of navigation in areas with significant elevation differences. However, the high-wave wakes and bubbles generated by vessels navigating through these tunnels inevitably alter the local flow conditions, making maneuvering difficult and increasing the risk of collisions, especially in the narrow tunnels. Therefore, it is necessary to analyze vessel wakes within navigation tunnels, particularly their wake wave height, to ensure safe navigation. Existing analyses of vessel wake wave heights within navigation tunnels neglect the influence of the tunnel cross-section and vessel morphology, resulting in incomplete physical analysis models and inaccurate results. Summary of the Invention

[0003] To address the aforementioned problems in the existing technology, this invention proposes a method and system for analyzing the impact of ship wake on navigation safety in navigation tunnels, which can improve the accuracy of ship wave height analysis results in navigation tunnels.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a method for analyzing the impact of ship wake on navigation safety in a navigation tunnel, comprising the following steps: Step S1: Obtain the average water depth h and cross-sectional diameter D in the navigation tunnel; monitor in real time the ship length L, waterline length LL, width B, draft T, displacement volume CUB, and speed V in the navigation tunnel; Step S2: Calculate the initial ship wake wave height H0 based on the speed V, width B, and draft T; Step S3: Calculate the navigation tunnel influence factor TUN based on the cross-sectional diameter D and width B; Step S4: Calculate the... Kelvin wake term KT; Step S5: Calculate the final ship wake wave height based on the initial ship wake wave height H0, the navigation tunnel influence factor TUN, and the Kelvin wake term KT, and perform a navigation safety level analysis for subsequent ships based on the final ship wake wave height; In step S5, the initial ship wake wave height H0, the navigation tunnel influence factor TUN, and the Kelvin wake term KT are multiplied to obtain the final ship wake wave height; When the final ship wake wave height is greater than or equal to a preset wave height reference value, the navigation safety level of subsequent ships is determined to be high risk, and when the final ship wake wave height is less than the preset wave height reference value, the navigation safety level of subsequent ships is determined to be low risk.

[0005] Further, the calculation of the initial ship wake wave height H0 in step S2 is specifically as follows: Step S21: Calculate the ratio of the average water depth h in the navigation tunnel to the ship length L, denoted as K1; Step S22: Determine whether K1 is less than a first preset threshold. If K1 is less than the first preset threshold, calculate the initial ship wake wave height H0 using the first formula; if K1 is not less than the first preset threshold, proceed to step S23; Step S23: Determine whether K1 is less than a second preset threshold. If K1 is less than the second preset threshold, calculate the initial ship wake wave height H0 using the second formula; otherwise, calculate the initial ship wake wave height H0 using the third formula.

[0006] Furthermore, the first formula in step S22 is: ; Where H0 represents the initial wake wave height of the ship, A1 represents the first adjustment coefficient, V represents the ship's speed in the navigation tunnel, g represents the gravitational acceleration, B represents the ship's width in the navigation tunnel, T represents the ship's draft in the navigation tunnel, and ST represents the ship type correction coefficient.

[0007] The second formula in step S23 is: ; Where A2 represents the second adjustment coefficient.

[0008] The third formula in step S23 is: ; Where A3 represents the third adjustment coefficient.

[0009] Further, in step S3, the navigation tunnel impact factor is calculated as follows: ; Where TUN represents the navigation tunnel impact factor, and A4 represents the fourth adjustment coefficient.

[0010] Further, the calculation of the Kelvin wake term KT in step S4 specifically includes the following steps: Step S41: Define the hull form factor SF, calculate the ratio of the displacement volume CUB to the hull coefficient, denoted as K2; the hull coefficient is the product of the hull waterline length LL, draft T, and hull width B; Step S42: Determine whether K2 is less than a third preset threshold. If K2 is less than the third preset threshold, assign SF the first value; otherwise, proceed to step S43; Step S43: Determine whether K2 is less than a fourth preset threshold. If K2 is less than the fourth preset threshold, assign SF the second value; otherwise, assign SF the third value; Step S44: Use the linspace function to generate 1000 equally spaced angle values ​​from negative π / 2 to positive π / 2, define the angle value number as i, and for each angle value θ... i The degree value θ is calculated based on the following formula. i The corresponding integral element IG i : ; Step S45: Calculate the Kelvin wake term KT based on the integrator IGe: ; Here, trapz() represents the numerical integration function.

[0011] The present invention also provides an analysis system for the impact of ship wake on navigation safety in navigation tunnels, used to perform the above-mentioned analysis method for the impact of ship wake on navigation safety in navigation tunnels. The analysis system for the impact of ship wake on navigation safety in navigation tunnels includes a data acquisition unit, a navigation safety level analysis unit, and an analysis result output unit. The data acquisition unit is connected to the navigation safety level analysis unit, and the navigation safety level analysis unit is connected to the analysis result output unit.

[0012] The beneficial technical effects of this invention compared with the prior art are as follows: when calculating the wake wave height of a ship, the cross-section of the navigation tunnel and the ship type are comprehensively considered. Compared with the prior art, this invention can improve the completeness of the physical analysis model of the wake wave height of a ship in the navigation tunnel and objectively improve the accuracy of the wave height analysis results. Attached Figure Description

[0013] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0014] Figure 1This is a simplified flowchart of the method for analyzing the impact of ship wake on navigation safety in a navigation tunnel in this invention; Figure 2 This is a simplified flowchart of the method for calculating the initial ship wake wave height H0 in this invention; Figure 3 This is a simplified flowchart of the method for calculating the Kelvin wake term KT in this invention. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] The concepts involved in this application will first be described with reference to the accompanying drawings. It should be noted that the following descriptions of various concepts are only for the purpose of making the content of this application easier to understand and do not constitute a limitation on the scope of protection of this application; furthermore, the embodiments and features in the embodiments of this application can be combined with each other unless otherwise specified. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0017] Refer to the instruction manual. Figure 1A method for analyzing the impact of ship wake on navigation safety in a navigation tunnel includes the following steps: Step S1: Obtain the average water depth h and cross-sectional diameter D in the navigation tunnel; monitor in real time the ship length L, waterline length LL, width B, draft T, displacement volume CUB, and speed V in the navigation tunnel; the above variables are the basic data for ship wake analysis in the navigation tunnel, which can be measured in real time by sensors, or the corresponding simulation parameters can be obtained during simulated navigation in the navigation tunnel; Step S2: Calculate the initial ship wake wave height H0 based on the speed V, width B, and draft T; Step S3: Calculate the navigation tunnel influence factor TUN based on the cross-sectional diameter D and width B; Step S4: According to the ship... Calculate the Kelvin wake term KT based on the length L and the ship's width B; Step S5: Based on the initial ship wake wave height H0, the navigation tunnel influence factor TUN, and the Kelvin wake term KT, multiply H0, TUN, and KT to obtain the final ship wake wave height. Then, based on the final ship wake wave height, analyze the navigation safety level of subsequent ships. When the final ship wake wave height is greater than or equal to a preset wave height reference value, the navigation safety level of subsequent ships is determined to be high risk; when the final ship wake wave height is less than the preset wave height reference value, the navigation safety level of subsequent ships is determined to be low risk. It is understood that multiple preset wave height reference values ​​can be set, and different navigation safety levels of subsequent ships correspond to different final ship wake wave heights falling between different preset wave height reference values.

[0018] Refer to the instruction manual. Figure 2 The calculation of the initial ship wake wave height H0 in step S2 specifically includes the following sub-steps: Step S21: Calculate the ratio of the average water depth h in the navigation tunnel to the ship length L, denoted as K1, to determine the water depth conditions of the water area where a specific ship is located in the navigation tunnel; Step S22: Determine whether K1 is less than a first preset threshold (0.3 is used in the simulation code program of this invention as the determination threshold for shallow water areas). When K1 is less than the first preset threshold, the initial ship wake wave height H0 is calculated using the first formula; when K1 is not less than the first preset threshold, proceed to step S23; Step S23: Determine whether K1 is less than a second preset threshold (which can be 0.5 as the determination threshold for medium water depth areas). When K1 is less than the second preset threshold, the initial ship wake wave height H0 is calculated using the second formula; otherwise, that is, when K1 is greater than or equal to the second preset threshold (at which point it is determined to be a deep water area condition), the initial ship wake wave height H0 is calculated using the third formula.

[0019] The first formula in step S22 is: ; Where H0 represents the initial wake wave height of the ship, A1 represents the first adjustment coefficient (which can be taken as 0.28), V represents the ship's speed in the navigation tunnel, g represents the gravitational acceleration, B represents the ship's width in the navigation tunnel, T represents the ship's draft in the navigation tunnel, and ST represents the ship type correction coefficient.

[0020] The second formula in step S23 is: ; Where A2 represents the second adjustment coefficient (which can be 0.25).

[0021] The third formula in step S23 is: ; Where A3 represents the third adjustment coefficient (which can be 0.2).

[0022] By calculating the ratio of the average water depth h to the ship length L and selecting a calculation mode based on this ratio, the sinking of the ship in a navigation tunnel can be simulated more accurately, thus improving the accuracy of wake wave height calculation. The first adjustment coefficient A1, the second adjustment coefficient A2, and the third adjustment coefficient A3 mentioned above represent empirical coefficients for ship wake wave height under different water depth conditions, reflecting the degree of wave energy concentration under different water depth conditions.

[0023] The calculation of the navigation tunnel impact factor in step S3 is specifically as follows: ; Where TUN represents the navigation tunnel influence factor, and A4 represents the fourth adjustment coefficient (which can be set to 0.85). By setting the navigation tunnel influence factor, the enhancement or superposition effect of the tunnel diameter on wave height can be reflected, making the above physical model more complete. The fourth adjustment coefficient A4 is an empirical proportionality coefficient used to adjust the influence intensity of the tunnel width B to water depth D on the tunnel constraint effect.

[0024] Refer to the instruction manual. Figure 3The calculation of the Kelvin wake term KT in step S4 specifically includes the following steps: Step S41: Define the hull form factor SF, calculate the ratio of the displacement volume CUB to the hull coefficient, denoted as K2; the hull coefficient is the product of the hull waterline length LL, draft T, and hull width B; Step S42: Determine whether K2 is less than a third preset threshold (which can be 0.6). If K2 is less than the third preset threshold, assign SF the first value; otherwise, proceed to step S43; Step S43: Determine whether K2 is less than a fourth preset threshold (which can be 0.8). If K2 is less than the fourth preset threshold, assign SF the second value; otherwise, assign SF the third value; the first value is less than the second value, and the second value is less than the third value. Using the third and fourth preset thresholds, the hulls of vessels navigating the tunnel are classified into three categories: conventional, small, and large hulls, to distinguish the differences in hydrodynamic characteristics between different hull types; Step S44: The linspace function (used to generate a uniformly distributed numerical sequence within a specified interval) is used to generate 1000 equally spaced angle values ​​from -π / 2 to π / 2, and the angle value is defined as numbered i. For each angle value θ i The degree value θ is calculated based on the following formula. i The corresponding integral element IG i : ; In the above formula, the first part of the multiplication sign is used to calculate the wake attenuation caused by the inner wall of the navigation tunnel, and the second part of the multiplication sign simulates the interaction between the waves and the ship hull, and is used to analyze the wave-making interference phenomenon of ships in the navigation tunnel. It should also be noted that the above multiplication sign can represent the vector dot product operation in the simulation program code.

[0025] Step S45: Based on the integral element IG i Calculate the Kelvin wake term KT: ; Here, trapz() represents a numerical integration function. Based on the trapezoidal rule, trapz() can calculate approximate values ​​of definite integrals of discrete data.

[0026] The present invention also provides an analysis system for the impact of ship wake on navigation safety in navigation tunnels, used to perform the above-mentioned analysis method for the impact of ship wake on navigation safety in navigation tunnels. The analysis system for the impact of ship wake on navigation safety in navigation tunnels includes a data acquisition unit, a navigation safety level analysis unit, and an analysis result output unit. The data acquisition unit is connected to the navigation safety level analysis unit, and the navigation safety level analysis unit is connected to the analysis result output unit. The aforementioned data acquisition unit is used to acquire basic data for ship wake analysis within the navigation tunnel. It comprises, but is not limited to, modules such as multiple sensors, rangefinders, CCD cameras, video transmission lines, video distributors, video capture cards, rudder angle measuring instruments, and a computer equipped with a real-time ship model measurement system. The navigation safety level analysis unit is used to calculate the final ship wake wave height and perform navigation safety level analysis. The analysis result output unit outputs the analysis results to inform subsequent ship navigation and implement different ship scheduling strategies. For example, if the navigation safety level of a following ship is determined to be high-risk, the following ship should switch to radar ARPA mode to dynamically monitor its distance from the preceding ship and implement a speed gradient management strategy, issuing warnings when necessary to allow the following ship to anchor and wait. If the navigation safety level of a following ship is determined to be low-risk, a sufficient safe distance (e.g., 3 times the length of the preceding ship) should be maintained, and the speed should be reduced (at least less than 8 knots) for recording in the navigation log. Furthermore, visualization tools can be used to display the relative positions of ships, arrows can be used to mark potential collision locations and collision probabilities, and algorithms such as Dijkstra's algorithm can be used to generate possible avoidance paths for following ships.

[0027] This invention provides an analysis system for the impact of ship wake on navigation safety within navigation tunnels. This system improves navigation management efficiency, scientifically allocates navigation tunnel resources, and intelligently prevents ship collision risks to ensure navigation safety. It also provides reference data for the construction and optimization of navigation tunnels.

[0028] The embodiments and / or implementation methods described above are merely preferred embodiments and / or implementation methods for implementing the technology of the present invention, and are not intended to limit the implementation methods of the technology of the present invention in any way. Any person skilled in the art can make some modifications or alterations to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as the technology or embodiments that are substantially the same as the present invention.

[0029] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A method for analyzing the impact of ship wake on navigation safety in a navigation tunnel, characterized in that, Includes the following steps: Step S1: Obtain the average water depth h and cross-sectional diameter D in the navigation tunnel; monitor in real time the ship length L, ship waterline length LL, ship width B, draft T, displacement volume CUB and speed V in the navigation tunnel. Step S2: Calculate the initial wake wave height H0 based on the travel speed V, ship width B, and draft T; Step S3: Calculate the navigation tunnel impact factor TUN based on the cross-sectional diameter D and the ship's width B; Step S4: Calculate the Kelvin wake term KT based on the ship length L and ship width B; Step S5: Based on the initial ship wake wave height H0, the navigation tunnel influence factor TUN, and the Kelvin wake term KT, calculate the final ship wake wave height, and perform a navigation safety level analysis for subsequent ships based on the final ship wake wave height. In step S5, the initial ship wake wave height H0, the navigation tunnel influence factor TUN, and the kelvin wake term KT are multiplied together to obtain the final ship wake wave height. When the final wake wave height of the vessel is greater than or equal to the preset wave height reference value, the navigation safety level of the following vessel is determined to be high risk; when the final wake wave height of the vessel is less than the preset wave height reference value, the navigation safety level of the following vessel is determined to be low risk.

2. The method for analyzing the impact of ship wake on navigation safety in a navigation tunnel according to claim 1, characterized in that, The calculation of the initial ship wake wave height H0 in step S2 is specifically as follows: Step S21: Calculate the ratio of the average water depth h in the navigation tunnel to the ship length L, denoted as K1; Step S22: Determine whether K1 is less than the first preset threshold. When K1 is less than the first preset threshold, calculate the initial ship wake wave height H0 using the first formula. Execute step S23 when K1 is not less than the first preset threshold. Step S23: Determine whether K1 is less than the second preset threshold. When K1 is less than the second preset threshold, calculate the initial ship wake wave height H0 using the second formula. Otherwise, the initial ship wake wave height H0 is calculated using the third formula.

3. The method for analyzing the impact of ship wake on navigation safety in a navigation tunnel according to claim 2, characterized in that, The first formula in step S22 is: ； Where H0 represents the initial wake wave height of the ship, A1 represents the first adjustment coefficient, V represents the ship's speed in the navigation tunnel, g represents the gravitational acceleration, B represents the ship's width in the navigation tunnel, T represents the ship's draft in the navigation tunnel, and ST represents the ship type correction coefficient.

4. The method for analyzing the impact of ship wake on navigation safety in a navigation tunnel according to claim 3, characterized in that, The second formula in step S23 is: ； Where A2 represents the second adjustment coefficient.

5. The method for analyzing the impact of ship wake on navigation safety in a navigation tunnel according to claim 4, characterized in that, The third formula in step S23 is: ； Where A3 represents the third adjustment coefficient.

6. The method for analyzing the impact of ship wake on navigation safety in a navigation tunnel according to claim 1, characterized in that, The calculation of the navigation tunnel impact factor in step S3 is specifically as follows: ； Where TUN represents the navigation tunnel impact factor, and A4 represents the fourth adjustment coefficient.

7. The method for analyzing the impact of ship wake on navigation safety in a navigation tunnel according to claim 2, characterized in that, The calculation of the Kelvin wake term KT in step S4 specifically includes the following steps: Step S41: Define the hull form factor SF, calculate the ratio of the displacement volume CUB to the hull coefficient, and denot it as K2; the hull coefficient is the product of the hull waterline length LL, draft T, and hull width B; Step S42: Determine whether K2 is less than the third preset threshold. When K2 is less than the third preset threshold, assign SF the first value. Otherwise, proceed to step S43; Step S43: Determine whether K2 is less than the fourth preset threshold. When K2 is less than the fourth preset threshold, assign SF the second value. Otherwise, assign SF the third value; Step S44: Use the linspace function to generate 1000 equally spaced angle values ​​from negative π / 2 to positive π / 2, define the angle value number as i, and for each angle value θ i The angle value θ is calculated based on the following formula. i The corresponding integral element IG i : ； Step S45: Based on the integral element IG i Calculate the Kelvin wake term KT: ； Here, trapz() represents the numerical integration function.

8. A system for analyzing the impact of ship wake on navigation safety in a navigation tunnel, used to execute the method for analyzing the impact of ship wake on navigation safety in a navigation tunnel as described in any one of claims 1-7, characterized in that, The system for analyzing the impact of ship wake on navigation safety in the navigation tunnel includes a data acquisition unit, a navigation safety level analysis unit, and an analysis result output unit. The data acquisition unit is connected to the navigation safety level analysis unit, and the navigation safety level analysis unit is connected to the analysis result output unit.

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