A method for determining the navigation width of a deep trench channel in a shallow sea area

Abstract

The present invention belongs to the field of water transport engineering channel construction, and discloses a method for determining the navigation width of a deep trench channel in a shallow sea area. Based on the actual ship navigation observation data of ships in an existing channel, the width of the track band is statistically calculated, as shown in the attached figure; a three-dimensional mathematical model is used to simulate the three-dimensional flow field of the channel of a cargo ship under different conditions, and the theoretical value of the wind flow pressure deflection angle under each condition is determined, and the distribution of the ship drift multiple is analyzed by using the Kolmonov-Smirnov test method, so as to determine the ship drift multiple under different guarantee rates. The method also takes into account the construction conditions and requirements of the proposed channel project, determines the guarantee rate value of the ship drift multiple, and calculates the navigation width of the channel accordingly. The present invention overcomes the problem that the ship drift multiple lacks the concept of guarantee rate and the wind flow pressure deflection angle value lacks the theoretical basis of fluid mechanics in the prior art, and realizes the coordination and unification of ship navigation safety and saving investment in channel engineering.

Description

Technical Field

[0001] The invention belongs to the field of water transport engineering channel construction, and particularly relates to a method for determining the navigation width of a deep trench channel in a shallow sea area based on actual ship navigation observation and taking into account a ship drift multiple guarantee rate. Background Art

[0002] The navigation width of a waterway refers to the designed navigation width of the waterway. According to the "General Design Specifications for Seaports" (such as JTS165-2013), it refers to the designed navigation depth and the cross-sectional width of the waterway. For artificial waterways, it refers to the cross-sectional width of the trench at the designed navigation depth. The determination of the navigation width of a waterway is mainly related to factors such as the type of navigable ships, the size of navigable ships, the designed speed, natural conditions such as water flow, wind, and waves, the operating level of pilots and drivers, the layout of breakwater gates, and the density and congestion of ships.

[0003] In the 1980s, my country's water transport engineering design department carried out large-scale actual ship navigation observations, observing a total of 66 ships, including 0.2~7.4 million ton general cargo ships, bulk carriers and oil tankers. Based on the actual ship observation results, an empirical formula for the channel width was derived, and the least squares method was used to draw a relationship curve to determine the wind flow pressure deflection angle and the corresponding drift multiple under different cross-current conditions. This was used as the calculation formula and parameters for the navigation width of the channel in my country's current "General Design Code for Seaports" (such as JTS165-2013). The calculation formula is as follows:

[0004] Single-line channel W=A+2c (1)

[0005] Two-line channel W=2A+b+2c (2)

[0006] A=n(Lsinγ+B) (3)

[0007] Where: A——track width;

[0008] n——ship drift multiple, according to the cross current, according to Table 6.4.2-1 of the "General Design Specifications for Seaports" JTS165-2013, ship drift multiple n and wind and flow pressure deflection angle γ value (see Fig.10 )Sure;

[0009] L——Design Captain;

[0010] B——designed ship breadth;

[0011] b——the margin between ships (m);

[0012] γ——wind and flow pressure deflection angle, according to the cross current, according to Table 6.4.2-1 of the "General Design Code for Seaports" JTS165-2013, the ship drift multiple n and the wind and flow pressure deflection angle γ value (see Fig.10)Sure;

[0013] c – The surplus width between the ship and the bottom of the channel.

[0014] Among them, the parameters of ship drift multiple and wind and flow pressure deflection angle are only related to the size of the cross current, and do not consider the influence of factors such as navigable ship type, ship tonnage and size, design speed, operating level of pilot and driver, construction conditions of the section (breakwater mouth section, outer section or general section), ship navigation density and congestion.

[0015] The application results show that the formula and parameters are generally reasonable and applicable, but the values ​​of the ship drift multiple and wind and flow pressure deflection angles cannot fully meet the development needs of water transport engineering, which is specifically reflected in:

[0016] 1. In recent years, the ships have been significantly larger, and the corresponding ship maneuverability has been significantly improved. However, due to the lack of actual navigation data of large ships as support, the existing specifications of wind flow pressure deviation angle and ship drift multiples may not be applicable. There are many disputes in the practical application of large-scale waterway projects. The waterway department believes that the waterway is wide enough, while the navigation department believes that the waterway is not wide enough.

[0017] 2. The current method for determining the values ​​of wind flow pressure angle and ship drift multiple does not take into account the differences in design speed, pilot and driver operating levels, ship traffic density and congestion conditions, and uniformly determines the values.

[0018] 3. The water flow conditions at the breakwater entrance section are relatively complex and are quite different from those at the non-breakwater entrance section. However, the ship drift multiples of the current method do not differentiate between the breakwater entrance section.

[0019] 4. The current method only uses empirical formulas, measured data and ship model data to determine the values ​​of wind and flow pressure deflection angles, and lacks a theoretical basis in fluid mechanics.

[0020] In view of the characteristics of deep-dug channels in shallow sea areas, such as long artificial excavation sections, large excavation depths, and large amounts of infrastructure dredging projects, the navigable width of the channel has a considerable impact on the project investment. This study proposes a method for determining the navigable width of deep-dug channels in shallow sea areas, which is of great significance for accurately determining the navigable width of deep-dug channels in shallow sea areas, ensuring the safety of ship navigation, and reasonably controlling the cost of channel construction and maintenance. Summary of the invention

[0021] The present invention provides a method for determining the navigation width of a deep trench channel in a shallow sea area, which solves the problem that the current formulas and parameters lack the concept of a ship drift multiple guarantee rate and the problem that the breakwater mouth section parameters lack specificity; at the same time, from the perspective of fluid mechanics, the wind and flow pressure deflection angles under different speeds and different cross-flow conditions are systematically and quantitatively determined, which solves the problem that in the current method, the wind and flow pressure deflection angles are based only on empirical formulas, measured data and ship model data but lack a theoretical basis in fluid mechanics.

[0022] To achieve the above objectives, the technical solution provided by the present invention includes:

[0023] A method for determining the navigation width of a deep trench channel in a shallow sea area comprises the following steps:

[0024] Step 1: Collect navigation data of the designed ship type navigating in the existing waterway, including basic ship information, track coordinates, bow direction, speed, etc.;

[0025] Step 2: Select the designed ship type of the existing waterway, conduct actual ship navigation observation in the existing waterway, obtain the measured navigation trajectory positioning data, and verify the data collected in step 1;

[0026] Step 3: Establish a numerical model of tidal currents in the sea area where the existing waterway is located, and calculate the hourly cross-currents along the existing waterway for the designed ship type under different tidal ranges;

[0027] Step 4: Collect the actual tidal range and actual tidal time of the ship sample of the designed ship type during the navigation of the existing waterway, and match them with the cross-current data calculated by the numerical model in step 3 to obtain the cross-current along the route during the navigation of the ship sample;

[0028] Step 5, determining the wind flow pressure deflection angle during the navigation of the sample ship according to the cross flow along the existing waterway during the navigation of the sample ship of the design ship type;

[0029] Step 6: Statistical analysis of the measured track width is performed based on the navigation section, ship type, and different wind flow pressure deflection angles, and the measured ship drift multiple is calculated;

[0030] Step 7: Statistical analysis is performed on the measured ship drift multiples, and distribution test is performed to calculate the ship drift multiples under different guarantee rates;

[0031] Step 8: Determine the guaranteed rate of the ship drift multiple for each section and each ship type according to the construction conditions and requirements of the proposed waterway project;

[0032] Step nine: Calculate the navigation track width and navigation channel width of the proposed waterway project based on the determined ship drift multiple and wind flow pressure deflection angle.

[0033] Furthermore, the method for collecting the navigation data of the designed ship type navigating in the existing waterway in step 1 is the AIS system.

[0034] Furthermore, the actual ship navigation observation method in step 2 is a GPS positioning system or a Beidou positioning system.

[0035] Furthermore, the tidal current numerical model in step three is a three-dimensional tidal current numerical model.

[0036] Furthermore, the statistical analysis of the measured ship drift multiples described in step seven is tested using the Kolmonov-Smirnov test method.

[0037] Furthermore, the guaranteed rate value of the ship drift multiple described in step eight is determined based on the quality of the navigation conditions of the section where the proposed waterway project is located, the safety requirements of navigable ships, the density of waterway traffic, the amount of waterway infrastructure construction and other construction conditions and requirements to determine the guaranteed rate value of the ship drift multiple for each ship type and each section of the proposed waterway project.

[0038] Furthermore, the wind flow pressure deflection angle value in step 5 is obtained by any of the following methods:

[0039] a. According to the maximum value of the cross-current along the ship sample during the voyage obtained in step 4, the relationship between the cross-current specification value and the wind flow pressure deflection angle specification value in the overall design specification for seaports is used to determine the wind flow pressure deflection angle during the voyage of the ship sample.

[0040] b. Use fluid mechanics calculation software to simulate the ship stress conditions of different ship types at different speeds, cross currents and cross wind combinations with different wind flow pressure deflection angles. Based on the principle of minimizing the lateral resistance of the ship, determine the theoretical values ​​of the wind flow pressure deflection angles of different ship types at different speeds, cross currents and cross wind combinations. According to the theoretical values ​​of the wind flow pressure deflection angles of different ship types at different speeds, cross currents and cross wind combinations, compare the ship type, speed, cross wind and other data obtained in step one, and the maximum value of the cross flow along the way obtained in step four, determine the wind flow pressure deflection angle of the ship sample of the design ship type in the existing waterway during navigation.

[0041] The method for determining the navigation width of the two types of shallow and deep trench channels in the sea areas determined according to the above technical scheme is as follows:

[0042] The first method for determining the navigation width of the shallow and deep trench channel in the sea area:

[0043] Step 1: Collect navigation data of designed ships (ships whose types and grades meet the design standards of existing waterways and whose fully loaded drafts) navigating in existing waterways through the AIS system, including basic ship information (ship type, tonnage, length L, ship width B, actual draft) and navigation data such as track coordinates, bow direction, speed, etc. throughout the waterway when sailing in and out of the port.

[0044] Step 2: Select the designed ship type for the existing waterway, conduct actual ship navigation in the existing waterway under typical high tide, medium tide or low tide conditions, use a positioning system (such as GPS or Beidou), conduct actual ship navigation observation, obtain the positioning data of the measured navigation trajectory, verify it with the data collected by the AIS system, analyze the distance deviation and speed deviation along the measured navigation trajectory of the positioning system and the AIS navigation trajectory, and verify the reliability of the AIS system data. The positioning system observation can be recorded throughout the process by the local pilot carrying a positioning instrument; it is advisable to use the ADCP navigation method to simultaneously conduct observations of flow velocity and direction in the waterway, and obtain waterway flow velocity and direction data synchronized with the actual ship navigation observation.

[0045] Step three, establish a three-dimensional tidal numerical model for the sea area where the existing waterway is located, and use the measured tide level, flow velocity and flow direction data of the sea area where the existing waterway is located to verify the three-dimensional tidal numerical model; simulate and calculate the hourly (such as 5 minutes time interval) stratified flow velocity and flow direction within the full load draft range of the ship type designed in step one in the existing waterway under different graded tidal ranges (such as tidal ranges of 5.0m, 4.5m, 4.0m, 3.5m, 3.0m, 2.5m, 2.0m, 1.5m, 1.0m, and the maximum and minimum tidal ranges must cover the astronomical high tides, astronomical medium tides, and astronomical low tides of previous years), and then obtain the corresponding cross currents.

[0046] Step 4: Collect the actual tidal range and actual tidal time (referring to the time before high and low tide) of each ship sample of the designed ship type in the existing waterway during the voyage. According to the actual tidal range (such as 4.75m) and the actual tidal time (such as 2 hours before high and low tide), match them with the cross-flow data of the corresponding adjacent graded tidal range and tidal time (such as 2 hours before high and low tide) calculated by the numerical model in step 3 (such as interpolating the cross-flow data 2 hours before high and low tide with a tidal range of 5.0m and the cross-flow data 2 hours before high and low tide with a tidal range of 4.5m), and obtain the hourly cross-flow along the route during the voyage of the ship sample.

[0047] Step 5: According to the maximum value of the cross-flow along the ship sample during the navigation of the design ship type in the existing waterway, the wind flow pressure deviation angle γ during the navigation of the ship sample is determined according to the "General Design Specifications for Seaports" (such as the wind flow pressure deviation angle corresponding to different cross-flows in Table 6.4.2.1 of JTS165-2013). g .

[0048] Step 6: Calculate the measured track width A by dividing the navigation section (breakwater entrance section, outer section or general section), ship type (bulk carrier, oil tanker, container ship, general cargo ship, chemical tanker, etc.), and different wind flow pressure deflection angles. s , according to the formula (3) converted to the formula (4), according to the wind flow pressure deflection angle γ g And the measured track width A s, calculate the measured ship drift multiple n for different ship types, different sections, and different wind flow pressure deflection angles s .

[0049]

[0050] Where: n s is the measured ship drift multiple, A s is the measured track width, L is the actual ship length in the basic information of AIS ship, B is the actual ship width in the basic information of AIS ship, γ g It is the wind flow pressure deflection angle in the "General Design Code for Seaports" (such as JTS165-2013).

[0051] Step seven, obtain the statistical results of the measured ship drift multiples of different ship types, different sections, and different wind flow pressure deflection angles, including mean, standard deviation, maximum value, minimum value, etc.; use the Kolmonov-Smirnov test method (i.e., KS test, which can infer whether the sample population obeys a certain theoretical distribution. It is a goodness of fit test method. The distributions that can be tested include normal distribution, GAMMA distribution, Poisson distribution, and exponential distribution. The test steps include: 1) Assume that the data set to be tested obeys a specific theoretical distribution; 2) Calculate the cumulative distribution function of the theoretical distribution; 3) Compare the empirical cumulative distribution function and the theoretical cumulative distribution function of the data set to be tested; 4) Compare the KS statistic with the critical value to determine whether it obeys the assumed theoretical distribution). s Perform distribution test to determine which probability density statistical function distribution (normal distribution / GAMMA distribution / Poisson distribution, etc.) the measured ship drift multiple obeys; according to the best fitting distribution function, calculate the ship drift multiple n value corresponding to the guarantee rate of 95%, 99%, 99.7%, 99.9%, etc. under different ship types, different sections, and different wind flow pressure deflection conditions.

[0052] Step 8: According to the construction conditions and requirements such as the navigation conditions of the proposed waterway project, the safety requirements of navigable ships, the density of waterway traffic, and the amount of waterway infrastructure, determine the guaranteed rate of ship drift multiples for each ship type and each section of the proposed waterway project, and then determine the value of ship drift multiples for each section and different wind flow pressure deflection conditions. If the navigation conditions of the section are good (such as a straight section), the safety requirements of navigable ships are low (such as bulk carriers), the waterway navigation density is small, and the waterway infrastructure construction is large, the guaranteed rate of ship drift multiples is 95~99% in principle; if the navigation conditions of the section are poor (such as the breakwater entrance section), the safety requirements of navigable ships are high (such as oil tankers), the waterway navigation density is large, and the waterway infrastructure construction is small, the guaranteed rate of ship drift multiples is 99.7%~99.9% in principle.

[0053] Step nine: Based on the value of the ship drift multiple determined in step eight and the value of the wind flow pressure angle in the Code for General Design of Seaports (such as JTS165-2013), use formula (3) to calculate the track width for each ship type, each section and each design cross-current condition of the proposed waterway project, and then use formulas (1) and (2) to calculate the navigation width of the waterway.

[0054] Compared with the existing technology, the first method for determining the navigation width of a deep trench channel in a shallow sea area has the following beneficial effects:

[0055] 1. The core content of the present invention is "to calculate the track width, the value of the ship drift multiple and its guarantee rate based on the actual ship navigation observation data of the existing waterway; to use the three-dimensional tidal numerical model to calculate the hourly crossflow within the full load draft depth range during the navigation period under the graded tidal range, and to match it with the actual tidal range and tidal time to determine the crossflow within the ship draft depth; to determine the ship drift multiple guarantee rate and the ship drift multiple value according to the construction conditions and requirements of the proposed waterway, and then determine the navigation width of the proposed shallow shoal deep trench waterway", which provides a scientific basis for reasonably determining the navigation width of the waterway of the shallow shoal deep trench waterway in the sea area, and realizes the coordination and unity of ship navigation safety and saving waterway engineering investment:

[0056] 1) The present invention adopts the ship AIS data containing the length, width, sailing time, tide level, sailing track coordinates and other information of actual sailing ships of different sections (breakwater mouth section, outer section or general section) and different ship types (bulk carrier, oil tanker, container ship, general cargo ship, chemical tanker, etc.), and obtains the ship drift multiple n value under different guarantee rates through statistical analysis. It not only adapts to the development trend of large-scale ships and improved ship maneuverability, but also solves the problem that the ship drift multiple in the current formula lacks the concept of guarantee rate.

[0057] 2) The drift multiples n of different ship types can be obtained, which makes up for the defect of no classification of ship types in the current method.

[0058] 3) The value of the ship drift multiple n suitable for the breakwater entrance section can be obtained, which solves the problem that the ship drift multiple in the current formula lacks specificity for the breakwater entrance section.

[0059] 4) A three-dimensional tidal numerical model is used to calculate the hourly cross-current within the full-load draft depth during the navigation period under graded tidal range, and the cross-current within the ship's draft depth is determined by matching it with the actual tidal range and tidal time. This significantly improves the cross-current accuracy, especially the cross-current accuracy under complex flow conditions, thereby significantly improving the statistical accuracy of the drift multiple of actual ships and their guarantee rate.

[0060] 5) It is proposed that "the guaranteed rate value of the ship drift multiples for each ship type and each section of the proposed waterway project shall be determined according to the construction conditions and requirements such as the quality of the navigation conditions of the section where the proposed waterway project is located, the safety requirements of the navigable ships, the density of navigation in the waterway, and the amount of waterway infrastructure projects", which solves the drawback of the current formula of "parameter values ​​​​do not consider the differences in construction conditions and requirements and are one-size-fits-all", and realizes the coordination and unity of ship navigation safety and saving investment in waterway projects.

[0061] The second method for determining the navigation width of the shallow and deep trench channel in the sea area:

[0062] Step 1 is the same as step 1 of the method for determining the navigable width of a deep trench channel in a shallow shoal in the first sea area.

[0063] Step 2 is the same as step 2 of the method for determining the navigable width of a deep trench channel in shallow waters in the first type of sea area.

[0064] Step three is the same as step three of the method for determining the navigable width of a deep trench channel in shallow waters in the first type of sea area.

[0065] Step 4 is the same as step 4 of the method for determining the navigable width of a deep trench channel in shallow waters in the first type of sea area.

[0066] Step 5: From the perspective of fluid mechanics, the following sub-steps are used to determine the wind flow pressure deflection angle of the ship sample of the design ship type during navigation in the existing waterway:

[0067] Step 5-1: Use fluid mechanics calculation software such as Fluent-3D, Flow-3D, etc. to establish a three-dimensional air-water flow mathematical model of the designed ship type, use the Realizable k-ε turbulence model to solve the turbulent viscosity coefficient, and use the VOF method to solve the phase interface of the air-water two-phase flow; to ensure the accuracy of the flow field simulation, the inlet boundary of the calculation domain is 5 ship lengths away from the bow, the outlet boundary is 10 ship lengths away from the stern, and the two side boundaries are 5 ship lengths away from the hull;

[0068] Step 5-2: Under different ship types, different speeds, cross currents and cross wind combinations, numerically simulate the three-dimensional air and water flow field of the ship when the wind flow pressure deflection angle is 1°, 2°, 3°, 4°...14° by enumeration method, and analyze the ship's navigation resistance, such as viscous resistance, wave resistance and air resistance, and the ship's lateral navigation resistance;

[0069] Step 5-3: Based on the principle of minimum lateral resistance of ship navigation, quantitatively determine the theoretical value of wind flow pressure deflection angle γ for different ship types under different speed, cross flow and cross wind combination conditions l ;

[0070] Step 5-4: Based on the theoretical values ​​of wind flow pressure deviation angles of different ship types under different combinations of speeds, cross currents and cross winds, and by comparing the ship type, speed, cross wind and other data obtained in step 1, as well as the maximum value of the cross current along the way obtained in step 4, determine the wind flow pressure deviation angle of the ship sample of the design ship type in the existing waterway during navigation.

[0071] Step 6: Calculate the measured track width A by dividing the navigation section (breakwater entrance section, outer section or general section), ship type (bulk carrier, oil tanker, container ship, general cargo ship, chemical tanker, etc.), and different wind flow pressure deflection angles. s , according to the formula (5) converted from the standard formula (3), according to the theoretical value of the wind flow pressure deflection angle γ l And the measured track width A s , calculate the ship drift multiple n for different ship types, different sections, and different wind flow pressure deflection angles s .

[0072]

[0073] Where: n s is the measured ship drift multiple, A s is the measured track width, L is the actual ship length in the basic information of AIS ship, B is the actual ship width in the basic information of AIS ship, γ l is the theoretical value of the wind flow pressure deflection angle.

[0074] Step seven is the same as step seven of the method for determining the navigable width of a deep trench channel in shallow waters in the first type of sea area.

[0075] Step eight is the same as step eight of the method for determining the navigable width of a deep trench channel in shallow waters in the first type of sea area.

[0076] Step 9: Take the value of the ship drift multiple determined in step 8 and the theoretical value of the wind flow pressure deflection angle γ l , Formula (3) is used to calculate the track width of the proposed waterway project for each ship type, each section and each design cross-current condition, and then Formulas (1) and (2) are used to calculate the navigation width of the waterway.

[0077] Compared with the existing technology, the second method for determining the navigation width of the deep trench channel in the shallow sea area has the following beneficial effects:

[0078] 1. The method for determining the navigation width of a deep trench channel in a shallow shoal is the same as that in the first type of sea area.

[0079] 2. The present invention proposes "using fluid mechanics calculation software (i.e., CFD software) to quantitatively study the forces on ships of different types at different speeds, cross currents and cross wind combinations with different wind flow pressure deflection angles, and based on the principle of minimizing the lateral resistance of the ship, determine the theoretical values ​​of wind flow pressure deflection angles of different ship types at different speeds, cross currents and cross wind combinations". From the perspective of fluid mechanics, the theoretical values ​​of wind flow pressure deflection angles of different ship types at different speeds, cross currents and cross wind combinations are quantitatively determined, which solves the problem that the wind flow pressure deflection angle in the current method is based only on empirical formulas, measured data and ship model data but lacks a theoretical basis in fluid mechanics, and also overcomes the problem that the current formula does not consider the influence of speed on wind and flow pressure deflection angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] Figure 1 It is a schematic diagram of the ship's navigation trajectory.

[0081] Figure 2 It is a schematic diagram of the cross-current distribution at a certain moment along the waterway obtained by tidal numerical simulation.

[0082] Figure 3 The measured ship drift multiple n of the breakwater entrance and outer sections of a 250,000-ton bulk carrier s Value statistics chart (extraoral segment-γ g =5°).

[0083] Figure 4 The measured ship drift multiple n of the breakwater entrance and outer sections of a 250,000-ton bulk carrier s Value statistics chart (breakwater entrance section -γ g =7°).

[0084] Figure 5a is the ship drift multiple n s Distribution test chart (extraoral segment-γ g =5°).

[0085] Figure 5b is the probability distribution diagram of different guarantee rates (extraoral segment-γ g =5°).

[0086] Figure 6a is the ship drift multiple n s Distribution test chart (extraoral segment-γ g =7°).

[0087] Figure 6b is the probability distribution diagram of different guarantee rates (extraoral segment-γ g =7°).

[0088] Figure 7a This is the ship surface velocity distribution diagram simulated by the FLUENT-3D three-dimensional model.

[0089] Figure 7b This is the mid-layer flow velocity distribution diagram of the ship simulated by the FLUENT-3D three-dimensional model.

[0090] Figure 7c This is the velocity distribution diagram of the bottom layer of the ship simulated by the FLUENT-3D three-dimensional model.

[0091] Figure 8 It is a schematic diagram of the local three-dimensional streamlines and turbulent energy distribution of a ship simulated by the FLUENT-3D three-dimensional model.

[0092] Fig. 9 It is the changing trend of the lateral resistance of ships under different cross currents and different combinations of wind flow pressure angles (cross wind level 7, speed 8kn).

[0093] Fig.10 It is the ship drift multiple n and wind and flow pressure deflection angle γ value in Table 6.4.2-1 of the "General Design Code for Seaports" JTS165-2013. DETAILED DESCRIPTION

[0094] The present invention is further described below in conjunction with embodiments and drawings.

[0095] Embodiment 1: Method for determining the navigation width of a deep trench channel in a shallow sea area

[0096] Project conditions: A 300,000-ton bulk carrier channel is required in a coastal area of ​​my country. There is an existing 250,000-ton bulk carrier channel, which is about 52km long, with a designed navigation width of 270m and a bottom elevation of -19.8m, which can meet the one-way navigation of 250,000-ton bulk carriers at high tide, with a designed speed of 8kn.

[0097] Step 1: Through the AIS system, the actual navigation data of 181 250,000-ton bulk carriers in the existing 250,000-ton bulk carrier channel are collected (data time limit 2013-2019), as shown in Table 1 Ship trajectory table.

[0098] Table 1 Ship trajectory table

[0099]

[0100] Step 2: Select a 250,000-ton bulk carrier to conduct three GPS ship observations in the existing 250,000-ton bulk carrier channel. The local pilot will carry a locator and record the entire process. Verify with the data collected by the AIS system. The maximum deviation between the GPS measured navigation track and the AIS navigation track does not exceed 10m. Relative to the navigation width of the channel, the deviation is very small, that is, the accuracy of the ship navigation data obtained by the AIS system can meet the calculation requirements. At the same time, the ADCP navigation method is used to synchronously carry out flow velocity and direction observations in the channel to obtain channel flow velocity and direction data synchronized with the actual ship navigation observation.

[0101] Step 3: Establish a three-dimensional tidal numerical model for the sea area where the existing 250,000-ton bulk carrier channel is located, and use the measured tide level, flow velocity, and flow direction data for verification and calibration, with the accuracy meeting the regulatory requirements. Simulate and calculate the hourly (e.g., 5-minute interval) tide level, stratified flow velocity, and flow direction of the designed ship type in step 1 under different tidal ranges (as shown in Table 2, 5 to 6 hours after high tide under a tidal range of 5 m) in the existing channel, and calculate the hourly crossflow within the full-load draft range of the designed ship type along the channel. The typical mid-tide crossflow is shown in Tables 2 and Figure 2 .

[0102] Table 2 Cross current at a certain point in the channel at each hour (time interval is 5 minutes)

[0103]

[0104] Step 4: Collect the actual tidal range and actual tidal time (the time from high tide) during the voyage of each ship sample. Match the actual tidal range (2.5m) and actual tidal time (e.g. 6 hours after high tide) with the cross-flow data of tidal range 2.5m and tidal time (e.g. 6 hours after high tide) calculated by numerical model in step 3 to obtain the hourly cross-flow along the route during the voyage of the ship sample. Table 3 shows the cross-flow calculation results along the route of a certain sample.

[0105] Table 3 Cross-current calculation along a real ship sample

[0106]

[0107] Step 5: According to the maximum value of the cross flow along the ship sample during the voyage, the relationship between the cross flow standard value and the wind flow pressure angle standard value in the "General Design Code for Seaports" JTS165-2013 is checked in the table (see Fig.10 ), determine the wind flow pressure deflection angle γ during the voyage of the ship sample g , as shown in Table 4, the values ​​of wind and flow pressure deflection angle γ.

[0108] Table 4 Values ​​of wind and flow pressure deflection angle γ

[0109]

[0110] Step 6: Calculate the measured track width A by dividing the route into sections (breakwater entrance section, outer section) and different wind flow pressure deflection angles s . Outer section of the channel entrance γ g =5°, the total number of track width samples is 489, and the data interval is [66.7, 160.2]; the outer segment γ g =7 °, the total number of track width samples is 43, the data interval is [73.5, 148.0]; breakwater mouth section γ g=7°, the total number of track width samples is 45, and the data interval is [81.8, 181.6].

[0111] According to the specification, the wind flow pressure deflection angle γ g And the measured track width A s , using formula (4), the measured ship drift multiple n is calculated s . After calculation, the extraoral segment γ g =5°, measured ship drift multiple n s Data interval [0.78, 1.84]; extraoral segment γ g =7°, measured ship drift multiple n s Data interval [0.76, 1.57]; entrance segment γ g =7°, measured ship drift multiple n s Data interval [0.84, 1.83], see Figure 3 , Figure 4 .

[0112] Step 7: Count the measured ship drift multiples at different sections and different wind flow pressure deflection angles, as shown in Table 5. s The values ​​are shown in the statistical table.

[0113] Table 5 Measured ship drift multiple n s Value statistics table

[0114]

[0115] The Kolmonov-Smirnov test method is used to test the measured ship drift multiple n. s The distribution test is carried out, and the GAMMA distribution is followed. The ship drift multiple n values ​​corresponding to the guarantee rates of 95%, 99%, 99.7%, etc. are calculated, as shown in Table 6. s The distribution fitting results are shown in Figure 5a , Figure 5b Extraoral segment-γ g =5° when the ship drift multiple is n s Distribution test and probability distribution diagrams of different assurance rates, Figure 6a , Figure 6b Breakwater Entrance Section-γ g =7° when the ship drift multiple is n s Distribution test and probability distribution plots for different assurance rates.

[0116] Table 6 Measured ship drift multiple n s Distribution fitting results

[0117]

[0118] Step eight, according to the engineering characteristics and requirements such as the quality of navigation conditions in the section where the proposed 300,000-ton bulk carrier channel project is located, the safety requirements of navigable ships, the density of navigation in the channel, the amount of channel infrastructure engineering, etc., determine the guaranteed rate value of the ship drift multiple in each section of the 300,000-ton bulk carrier channel project, and then determine the ship drift multiple value in each section and under different wind flow pressure deflection conditions, as shown in Table 7.

[0119] Table 7 Guaranteed rate of ship drift multiple and value of ship drift multiple

[0120]

[0121] Step 9. Based on the value of the ship drift multiple determined in step 8 and the standard value of the wind flow pressure deflection angle, use formula (3) to calculate the track width of each section and each design cross-current condition of the proposed 300,000-ton bulk carrier channel project. Then use formulas (1) and (2) to calculate the navigation width of the 300,000-ton bulk carrier channel project, as shown in Table 8.

[0122] Table 8 Calculation table of navigation width of waterway

[0123]

[0124] Embodiment 2: Method for determining navigation width of second type of shallow shoal deep trench channel

[0125] Project conditions: A 300,000-ton bulk carrier channel is required in a coastal area of ​​my country. There is an existing 250,000-ton bulk carrier channel, which is about 52km long, with a designed navigation width of 270m and a bottom elevation of -19.8m, which can meet the one-way navigation of 250,000-ton bulk carriers at high tide, with a designed speed of 8kn.

[0126] Step 1: The method for determining the navigation width of a deep trench channel in shallow waters is the same as that in the first type of sea area.

[0127] Step 2: The method for determining the navigable width of a deep trench channel in shallow waters is the same as that in the first type of sea area.

[0128] Step three, the method for determining the navigable width of the deep trench channel in the shallow sea area is the same as the first method.

[0129] Step 4: The method for determining the navigable width of the deep trench channel in the shallow sea area is the same as the first method.

[0130] Step 5: Use Fluent-3D three-dimensional mathematical model to simulate the three-dimensional flow field of a 250,000-ton bulk carrier under different speeds, typical cross currents and cross wind combinations, such as Figure 7a , Figure 7b , Figure 7c , Figure 8As shown in the figure, the longitudinal and transverse resistances of the ship are calculated successively by enumeration method when the wind flow pressure deflection angle is 3°, 4°...14°; based on the principle of minimum transverse resistance of the ship, the theoretical value of wind flow pressure deflection angle γ under different speed, cross flow and cross wind combination conditions is determined l Among them, under the conditions of level 7 crosswind, speed 8kn, and cross current 1.0m / s, the lateral resistance of the hull is the smallest when the wind flow pressure angle is 14.0°. Fig. 9 As shown in Table 9, the theoretical values ​​of the ship wind flow pressure deflection angle under different cross flow and cross wind combinations are shown.

[0131] Table 9 Theoretical values ​​of wind flow pressure deflection angle of ships under different cross flow and cross wind combination conditions (speed 8kn)

[0132]

[0133] According to the theoretical values ​​of the wind flow pressure deviation angle under different combinations of speeds, cross currents and cross winds, and by comparing the ship type, speed, cross wind and other data obtained in step one, as well as the maximum value of the cross current along the way obtained in step four, the wind flow pressure deviation angle of the ship sample of the design ship type in the existing waterway during navigation is determined.

[0134] Step 6: Under the conditions of crosswind level 7 and speed of 8kn, the track width is counted at different wind flow pressure angles. For the outer section of the channel, γ1=4°, the total number of track width samples is 489, and the data interval is [66.7, 160.2]; for the outer section, γ1=7.5°, the total number of track width samples is 43, and the data interval is [73.5, 148.0]; for the breakwater entrance section, γ1=7.5°, the total number of track width samples is 45, and the data interval is [81.8, 181.6].

[0135] According to the theoretical value of wind flow pressure angle γ1 and the measured track width A s , using formula (5), the measured ship drift multiple n is calculated s After calculation, the outer section γ1 = 4°, the measured ship drift multiple n s Data interval [0.84, 1.97]; Outer section γ1 = 7.5°, measured ship drift multiple n s Data interval [0.74, 1.53]; breakwater entrance section γ1 = 7.5°, measured ship drift multiple n s Data range [0.82, 1.78].

[0136] Step 7: Count the measured ship drift multiples at different sections and different wind flow pressure deflection angles, as shown in Table 10. s Value statistics table.

[0137] Table 10 Measured ship drift multiple n s Value statistics table

[0138]

[0139] The Kolmonov-Smirnov test method is used to test the measured ship drift multiple n. s The distribution test is carried out and it obeys the GAMMA distribution. The ship drift multiples corresponding to the guarantee rates of 95%, 99%, 99.7%, etc. are calculated, as shown in Table 11. The measured ship drift multiples n s The distribution fitting results are shown in Figure 2.

[0140] Table 11 Measured ship drift multiple n s Distribution fitting results

[0141]

[0142] Step eight, according to the engineering characteristics and requirements such as the quality of navigation conditions in the section where the proposed 300,000-ton bulk carrier channel project is located, the safety requirements of navigable ships, the density of navigation in the channel, the amount of channel infrastructure engineering, etc., determine the guaranteed rate value of the ship drift multiple in each section of the 300,000-ton bulk carrier channel project, and then determine the ship drift multiple value in each section and under different wind flow pressure deflection conditions, as shown in Table 12.

[0143] Table 12 Ship drift multiple guarantee rate and ship drift multiple n value

[0144]

[0145] Step 9. Based on the value of the ship drift multiple determined in step 8 and the theoretical value of the wind flow pressure angle, the width of the navigation track of each section of the proposed 300,000-ton bulk carrier channel project under each design cross-current condition is calculated using formula (3). Then, the navigation width of the 300,000-ton bulk carrier channel project is calculated using formulas (1) and (2), as shown in Table 13.

[0146] Table 13 Calculation table of navigation width of waterway

[0147]

[0148] The above-mentioned related explanations and descriptions of the embodiments are for the convenience of those skilled in the art to understand and apply the present invention. It is obvious that those familiar with the art can easily make various modifications to these contents and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above-mentioned related explanations and descriptions of the embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A method for determining the navigation width of a deep trench channel in a shallow sea area, characterized in that: The following steps are involved: Step 1: collecting navigation data of the designed ship type navigating in the existing waterway, wherein the navigation data includes basic information of the ship, track coordinates, heading, and speed; Step 2: Select the designed ship type of the existing waterway, conduct actual ship navigation observation in the existing waterway, obtain the measured navigation trajectory positioning data, and verify the data collected in step 1; Step 3: Establish a numerical model of tidal currents in the sea area where the existing waterway is located, and calculate the hourly cross-currents along the existing waterway for the designed ship type under different tidal ranges; Step 4: Collect the actual tidal range and actual tidal time of the ship sample of the designed ship type during the navigation of the existing waterway, and match them with the cross-current data calculated by the numerical model in step 3 to obtain the cross-current along the route during the navigation of the ship sample; Step 5: According to the cross flow along the existing waterway during the navigation of the ship sample of the design ship type, the wind flow pressure deflection angle during the navigation of the ship sample is determined by any of the following methods: a. According to the maximum value of the cross flow along the ship sample during the voyage obtained in step 4, the relationship between the cross flow standard value and the wind flow pressure deflection angle standard value in the general design code for seaports is used to determine the wind flow pressure deflection angle during the voyage of the ship sample; b. Use fluid mechanics calculation software to simulate the ship stress conditions of different ship types at different speeds, cross currents and cross wind combinations with different wind flow pressure deflection angles. Based on the principle of minimum lateral resistance of the ship, determine the theoretical values ​​of wind flow pressure deflection angles of different ship types at different speeds, cross currents and cross wind combinations. According to the theoretical values ​​of wind flow pressure deflection angles of different ship types at different speeds, cross currents and cross wind combinations, compare the data including ship type, speed, cross wind obtained in step one, and the maximum value of the cross flow along the way obtained in step four, determine the wind flow pressure deflection angle of the ship sample of the design ship type in the existing waterway during navigation. Step 6: Statistical analysis of the measured track width is performed based on the navigation section, ship type, and different wind flow pressure deflection angles, and the measured ship drift multiple is calculated; Step 7: Statistical analysis is performed on the measured ship drift multiples, and distribution test is performed to calculate the ship drift multiples under different guarantee rates; Step 8: Determine the guaranteed rate of the ship drift multiple for each section and each ship type according to the construction conditions and requirements of the proposed waterway project; Step nine: Calculate the navigation track width and navigation channel width of the proposed waterway project based on the determined ship drift multiple and wind flow pressure deflection angle.

2. The method according to claim 1, characterized in that The method for collecting the navigation data of the designed ship type navigating in the existing waterway in step 1 is the AIS system.

3. The method according to claim 2, characterized in that The actual ship navigation observation method described in step 2 is the GPS positioning system or the Beidou positioning system.

4. The method according to claim 3, characterized in that The tidal current numerical model described in step three is a three-dimensional tidal current numerical model.

5. The method according to claim 4, characterized in that The statistical analysis of the measured ship drift multiples described in step 7 is tested using the Kolmonov-Smirnov test method.

6. The method according to claim 5, characterized in that The guaranteed rate value of the ship drift multiple described in step eight is determined according to the construction conditions and requirements for each ship type and each section of the proposed waterway project; the construction conditions and requirements include the quality of the navigation conditions of the section where the proposed waterway project is located, the safety requirements of navigable ships, the density of waterway navigation, and the amount of waterway infrastructure construction.

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