Ship type for ship body molded line of inland river ro-ro passenger ship and molded line design method

Abstract

According to the hull molded line ship type for the inland river ro-ro passenger ship and the design method, the molded line of the ship type adopts a super-baseline three-tail large-outer-floating cross section molded line, the ship type can be well used for the inland river ro-ro passenger ship, propellers are arranged at the tail ends of the three tails, the front three tails of the propellers adopt the super-baseline molded line, and therefore the height of the center line of a shaft system can be reduced, and the ship type can be used for the inland river ro-ro passenger ship. And the cross section molded line of the ship body adopts a large outer drift, so that a large-area deck area is obtained by using a small displacement, and a huge vehicle carrying area is obtained. The large longitudinal flow head molded line can obtain excellent rapid performance, the ship body molded line is subjected to multi-round optimization and repeated calculation, a ship model test method is finally adopted, the test is subjected to CCS field verification, and the result shows that the test can reach the current standard: the inland river ro-ro passenger ship green III level; and the rapidity and safety of the ship are effectively improved, energy conservation and emission reduction of the ship are achieved, the transportation cost of the ship is effectively reduced, and economic benefits are remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the field of ro-ro ships, and particularly relates to a hull form and a form line design method for an inland river passenger ro-ro ship. Background Art

[0002] In recent years, especially at the present stage, the development of inland river ship hull forms in China has been rapid and diverse. Currently, common stern forms include twin-screw stern, twin bulbous stern, twin yawed stern, nozzle stern, single-screw stern, twin skegs, etc., and bow forms include pointed bow, bulbous bow, vertical bow, V-shaped bow, U-shaped bow, flat bow, full-form coefficient obese bow, etc. These hull forms have their own advantages and disadvantages. Among them, the advantages and disadvantages of the hull form have a great impact on the safety and economy of the ship, especially in the period of high oil prices, low freight rates and high labor costs.

[0003] As the main ship for inland river transportation, the hull form design of inland river passenger ro-ro ships directly affects the energy conservation and emission reduction performance of the ships. Therefore, how to design the hull form of inland river passenger ro-ro ships to improve the ship's speed, safety, achieve ship energy conservation and low carbon, and obtain significant economic and social benefits is an important development direction for the inland river ro-ro ship industry.

[0004] The existing inland river passenger ro-ro ships mainly adopt the "Chuanjiang 60-car cargo vehicle ro-ro ship". The total length of the hull of this ship form is 113.8 m, the waterline length is 111.6 m, the length between perpendiculars is 110.0 m, the overall width is 25.40 m, the molded width is 23.10 m, the molded depth is 4.40 m, the designed draft is 2.80 m, the station spacing is 5.5 m, the frame spacing is 0.50 m, and the sheer is 0.20 m. The shape of the stern body of this ship form adopts a design that does not exceed the baseline, and the disadvantages of the stern body being short and obese in the height direction and unable to form a slender streamline shape, resulting in a relatively small deck width and limited loading capacity. If the deck width is simply increased, a large midship cross-sectional area needs to be adopted, which will lead to an increase in the full load waterline width. Summary of the Invention

[0005] The object of the present invention is to provide a hull form and hull line design method for inland river ro-ro passenger ships. The hull line of this hull form adopts a three-tail type with a super baseline and a large outward drift cross-sectional line, which can be well used for inland river ro-ro passenger ships. By arranging a propeller at the end of the three-tail, and the first three-tail of the propeller adopts a super baseline line, the height of the shafting center line can be reduced, so as to be suitable for designing a large-diameter propeller. The hull cross-sectional line adopts a large outward drift, so as to obtain a large deck area with a small displacement and obtain a large vehicle-carrying area. The large longitudinal flow bow line can obtain excellent speed performance. The hull line of the present invention has been optimized in multiple rounds and calculated repeatedly. Finally, the method of ship model test is adopted, and its test has been verified on-site by CCS. The results show that it can meet the current standard: Green Class III for inland river ro-ro passenger ships; and effectively improve the speed and safety of the ship, realize energy conservation and emission reduction of the ship, effectively reduce the transportation cost of the ship, and significantly improve the economic benefits.

[0006] In order to achieve the above technical features, the object of the present invention is achieved as follows: A hull form for an inland river ro-ro passenger ship, the hull form adopts a three-tail line with a super baseline. A propeller is provided at the end of the three-tail. The super baseline three-tail forms a slender and smooth water droplet-shaped cross-sectional line in the height direction, so that the oncoming flow in front of the propeller is sufficient; the super baseline three-tail is used to reduce the height of the propeller shafting center line, so that the radius from the propeller to the ship bottom plate increases, so as to adopt a large-diameter propeller to improve the propeller propulsion efficiency; at the same time, the super baseline three-tail makes each individual tail fin form a slender water droplet-shaped cross-sectional line, making it slender and smooth in the height direction.

[0007] Preferably, the super baseline three-tail extends forward to the engine room section. The tops of the two tunnels between the left and right tails and the middle tail are designed as large arc cross-sections convex downward, and through repeated optimization and iterative CFD simulation calculations, the tunnel top line is obtained, so as to make the water flow smooth and the pressure distribution uniform.

[0008] Preferably, at the position where each single tail installs a gearbox or a motor in the engine room section, based on the characteristic of the reduction of the propeller shafting center line, the lower half of the gearbox or the motor can be installed downward beyond the baseline, so as to reduce the center of gravity of the ship and realize the optimal layout of the engine room equipment in the height direction.

[0009] Preferably, both sides of the top of each single tail are designed as vortex-like tails with shallow vortex grooves, so as to maximize the height of the cross-sectional line of each single tail and make the oncoming flow in front of the propeller more abundant.

[0010] Preferably, the cross-sectional lines on both sides adopt large outward drift cross-sectional lines, so as to obtain a sufficient deck area with a small displacement.

[0011] Preferably, the large longitudinal flow bow adopts a longitudinal mid-section line with a small inflow angle and a downward convex U-shaped arc cross-sectional line. Through CDF simulation calculations, the pressure distribution at the bow is uniform and the resistance is reduced.

[0012] Preferably, the ship shape is further optimized based on the "60-berth cargo roll-on / roll-off ship on the Sichuan section of the Yangtze River", which is the main ship type in the existing roll-on / roll-off market on the Sichuan section of the Yangtze River.

[0013] Preferably, on the other hand, the present invention provides a method for designing the hull lines of an inland river passenger roll-on / roll-off ship. Determine the main dimensions of the ship, and use CAD drawing software to draw the grid lines of the longitudinal section and the transverse section of the waterline. Specifically, it includes the following steps: S1. Draw the three-view contour lines of the ship length, ship width, and molded depth. Combine with the general arrangement plan to draw the position lines of each cabin. S2. According to the requirements of the marine engineering specialty, draw the center line of the rudder system, the half-width, height, and propeller installation position of the shafting center line on the drawing. S3. Determine the longitudinal position where the gearbox or motor is located according to the engine room layout. After determining the position, proceed with the hull line design and drawing according to S4.

[0014] Preferably, S4 includes the following steps: S4.1. Obtain the diameter of the tail shaft and tail pipe of the marine engineering specialty at the outlet of the three-shaft system at the tail end, and give it on the transverse section, longitudinal section, and waterline; obtain the installation dimensions of the gearbox from the marine engineering specialty, and sketch the width on the shafting center line of the transverse section. This width is determined by the gearbox width + the width of the engine room solid floor + a suitable gap. Based on this width, give the half-width points of each waterline one by one, and connect the points to form a smooth water droplet-shaped transverse section line. S4.2. After the transverse section line at the gearbox position is drawn, draw the sketches of the three-tail transverse section lines of each station backward and forward. First, perform preliminary fairing from the water surface according to the sketches, and wait for the next step after completion. S4.3. Refer to the transverse section line of the reference ship hull line. According to the main dimension width of the new ship, comprehensively consider the midship section area to draw the midship section line of the new ship with large outer drift and large round bilge. Draw the transverse section line of the bow closure plate at the bow and the plate line of the stern closure plate at the stern. After completion, according to the trend of the bow, midship section, and three-tail sketches, give the transverse section lines of each station one by one. S4.4. After the sketches of each station are drawn, continue to supplement and draw the large arc tunnel top line that protrudes downward from the top of the three-tail intermediate tunnel at each station. On both sides of the top of each single tail of the three-tail, draw the vortex-like tail hull line with shallow vortex grooves according to experience and referring to the reference ship, and at the same time, smoothly connect it with the side and each single tail of the three-tail to obtain a preliminary complete three-tail hull line above the baseline. S4.5. Refer to the bow hull line of the reference ship and optimize and transform it in combination with the width and molded depth of the new ship. The drawing principle is a large longitudinal flow bow and a downward convex large arc V-shaped transverse section bow hull line. S4.6. After the completion of the above sketches, conduct preliminary fairing on AutoCAD software, and copy the lines of the inland river ro-ro passenger ship with three transom sterns above the baseline, large outward flotation, and large longitudinal flow to the HD-SHM hull line system software for fine fairing. Thus, a preliminary lines plan is obtained. S4.7. Conduct hydrostatic and performance calculations, and make appropriate optimizations based on the hydrostatic calculation results until the design requirements are met. S4.8. Conduct CFD simulation calculations, further optimize, and perform iterative calculations repeatedly until all the target indicators of the design task are met. S4.9. After the CFD simulation calculations meet the requirements, conduct model tests. The ship model tests should apply for on-site verification by the China Classification Society, aiming to meet the standards of Green Ship Class III for ro-ro passenger ships.

[0015] Preferably, the appropriate optimization in S4.7 includes the optimization of the longitudinal position of the center of buoyancy and displacement.

[0016] The present invention has the following beneficial effects: 1. Each single piece of the present invention can form a slender streamlined profile. Such a profile enables this lines plan to form a three-sided fairing streamlined line in the waterplane, longitudinal section, and transverse section. The three transom sterns above the baseline are suitable for installing large-diameter propellers, which can lower the centerline of the shafting, increase the distance between the centerline of the shafting and the ship bottom plate at this location, and thus install large-diameter propellers. In this way, the three transom sterns above the baseline can obtain a three-sided fairing and slender three-transom stern lines plan, and can install the optimal large-diameter propellers, thereby increasing the thrust.

[0017] 2. The three transom sterns above the baseline of the present invention extend longitudinally forward to the front end of the engine room, and the middle section of each single transom stern is located at the position of the gearbox or motor. Determine the width at this location according to the installation dimensions of the gearbox or motor + the width of the engine room solid floor + a suitable gap; the width of the main engine position (except for electric propulsion ships) before the gearbox or motor is generally smaller than that of the gearbox position. Coupled with the fact that the formation of the ship lines plan is wider closer to the midsection, the passage between the two sides of the machinery space can meet the usage requirements.

[0018] 3. For the three transom sterns above the baseline of the present invention, due to the lowering of the centerline of the shafting, the gearbox (or motor) can be centered on the centerline of the shafting and install its lower half body inside the single piece of each unit, realizing the lowering of the ship's center of gravity, which is beneficial to increasing the stability margin and optimizing the space in the direction of the engine room height.

[0019] 4. The lines plan of the three transom sterns above the baseline of the present invention is designed with a large downward convex arc at the top of the tunnel between the left and right middle transoms. After multiple iterative optimizations and CFD simulation calculations, the final lines plan of the downward convex large arc tunnel top between the three transoms is obtained.

[0020] 5. On both sides of the top of each single tail fin of the three tails of the present invention, a profile line with shallow vortex grooves is designed. Such a profile line increases the height of each single tail fin body. At the same time, since the vortex grooves can induce the pre-whirl of the counter-rotating propeller, the rotating wake is thus changed into a tendency of a direct current jetting backward, thereby reducing the large amount of energy carried away by the rotation of the propeller wake helix. The vortex can recover the rotational energy loss in the propeller wake.

[0021] 6. Since the cargo capacity required for the ship of the present invention is small, but the demand for the deck area is large, the hull of the present invention adopts a transverse profile line with large flare and large round bilge. Further optimization is carried out with the main ship type "Chuanjiang 60-car cargo vehicle ro-ro ship" in the existing Chuanjiang ro-ro market as the parent ship type. The maximum deck width is obtained with a smaller midship transverse sectional area. Such a transverse profile line with large flare and large round bilge realizes a smaller full load waterline width. In this way, the deck with a large width can also make the full load waterline designed into a waterplane profile line with a smaller bow inflow angle, making its streamline smoother. Compared with the same type of conventional profile line ships with the same main dimensions, it has significant speed advantages.

[0022] 7. For the ship type line of the present invention with a three-tail above the baseline, large flare, and large longitudinal flow at the bow, the large longitudinal flow at the bow adopts a longitudinal midsection profile line with a small inflow angle and a large downward convex U-shaped large arc transverse section line to obtain the maximum area of the whole ship's deck. The width of the main deck designed at the bow is the same as the width at the longitudinal middle part of the ship, forming a larger flare than the midship transverse profile line. Therefore, special consideration should be given to the structural design at the bow. Description of the Drawings

[0023] The present invention will be further described below in conjunction with the drawings and embodiments.

[0024] Figure 1 It is a drawing of a 121m passenger ro-ro ship in the Chuanjiang River.

[0025] Figure 2 (a) and (b) are the free surface waveform diagrams of the 121m passenger ro-ro ship in the Chuanjiang River calculated by CFD simulation Figure 1 in the Chuanjiang River.

[0026] Figure 3 It is the distribution diagram of the surface pressure coefficient at the stern of the 121m passenger ro-ro ship in the Chuanjiang River calculated by CFD simulation.

[0027] Figure 4 It is the longitudinal section profile line drawing of the 121m passenger ro-ro ship designed by the present invention.

[0028] Figure 5 The waterplane profile line drawing of the 121m passenger ro-ro ship in the Chuanjiang River.

[0029] Figure 6 The transverse section profile line drawing of the 121m passenger ro-ro ship in the Chuanjiang River.

[0030] Figure 7Drag tank test of 121m passenger and ro-ro ship model in the Chuanjiang River. Forecast curve of speed with D = 3m.

[0031] Figure 8 Side view of 121m truck ro-ro ship in the Chuanjiang River.

[0032] Figure 9 Main deck plan of 121m truck ro-ro ship in the Chuanjiang River after loading.

[0033] Figure 10 Main deck plan of 121m truck ro-ro ship in the Chuanjiang River.

[0034] Figure 11 Upper deck plan of 121m truck ro-ro ship in the Chuanjiang River.

[0035] Figure 12 Boat deck of 121m truck ro-ro ship in the Chuanjiang River.

[0036] Figure 13 Bridge deck plan of 121m truck ro-ro ship in the Chuanjiang River.

[0037] Figure 14 Canopy deck plan of 121m truck ro-ro ship in the Chuanjiang River.

[0038] Figure 15 Front view of 121m truck ro-ro ship in the Chuanjiang River below the upper deck.

[0039] Figure 16 For Figure 15 A - A view of 121m truck ro-ro ship in the Chuanjiang River.

[0040] Figure 17 Bilge plan of 121m truck ro-ro ship in the Chuanjiang River.

[0041] Figure 18 Longitudinal section line drawing of 130m passenger and ro-ro ship in the Chuanjiang River.

[0042] Figure 19 Waterplane section line drawing of 130m passenger and ro-ro ship in the Chuanjiang River.

[0043] Figure 20 Transverse section line drawing of 130m passenger and ro-ro ship in the Chuanjiang River.

[0044] Figure 21 Longitudinal section line drawing of 60 - berth passenger and ro-ro ship in the Chuanjiang River, proving that the three - tail of the parent ship does not exceed the baseline.

[0045] Figure 22 Waterplane section line drawing of 60 - berth passenger and ro-ro ship in the Chuanjiang River, proving that the tunnel between the three - tails is concave upward.

[0046] Figure 23 Transverse section line drawing of 60 - berth passenger and ro-ro ship in the Chuanjiang River, proving that the three - tail does not exceed the baseline. Detailed Implementation Modes

[0047] The following further describes the implementation modes of the present invention with reference to the accompanying drawings.

[0048] Embodiment 1: Refer to Figure 1-23 , a hull form for an inland river passenger and roll-on / roll-off ship. The hull form adopts a three-tail form beyond the baseline. A propeller is provided at the tail end of the three-tail. The three-tail beyond the baseline forms a slender and smooth water-drop-shaped cross-sectional line in the height direction, enabling sufficient oncoming flow in front of the propeller; the three-tail beyond the baseline is used to reduce the height of the center line of the propeller shafting, increasing the radius from the propeller to the ship bottom plate, so as to adopt a large-diameter propeller to improve the propeller propulsion efficiency; at the same time, the three-tail beyond the baseline makes each individual tail fin form a slender water-drop-shaped cross-sectional line, making it slender and smooth in the height direction.

[0049] Preferably, the three-tail beyond the baseline extends to the engine room section at the bow. The tops of the two tunnels between the left and right tails and the middle tail are designed as downwardly convex large-arc cross-sections, and through repeated optimization and iteration for CFD simulation calculations, the tunnel top profile line is obtained, thereby enabling smooth water flow and uniform pressure distribution.

[0050] Preferably, at the position where each single tail fin installs a gearbox or an electric motor in the engine room section, based on the characteristic of the reduction of the center line of the propeller shafting, the lower half of the gearbox or the electric motor is installed downward beyond the baseline to reduce the ship's center of gravity and achieve an optimized layout of the engine room equipment space in the height direction.

[0051] Preferably, both sides of the top of each single tail fin are designed as vortex-like tails with shallow vortex grooves, maximizing the height of the cross-sectional line of each single tail fin and achieving more abundant oncoming flow in front of the propeller.

[0052] Preferably, the two sides of the ship adopt a cross-sectional line with a large outward flare to obtain sufficient deck area with a small displacement.

[0053] Preferably, the large longitudinal flow bow at the bow adopts a longitudinal mid-section profile line with a small inflow angle and a downwardly convex U-shaped arc cross-sectional line. Through CDF simulation calculations, the pressure distribution at the bow is uniform and the resistance is reduced.

[0054] Preferably, the hull form is further optimized and designed with the existing main hull form "Chuanjiang 60-car cargo roll-on / roll-off ship" in the Chuanjiang roll-on / roll-off market as the parent hull form.

[0055] Preferably, on the other hand, the present invention provides a method for designing the hull form of a hull form for an inland river passenger and roll-on / roll-off ship. Determine the main dimensions of the ship and use CAD drawing software to draw the grid lines of the longitudinal section and the waterline cross-section; Specifically, it includes the following steps: S1, draw the three-view contour lines of the ship length, ship width, and molded depth, and combine with the general arrangement plan to draw the position lines of each cabin; S2, according to the marine engineering specialty, draw the rudder system centerline, shaft system centerline half width, height, and propeller installation position in the diagram; S3, determine the longitudinal position of the gearbox or motor according to the cabin layout. After the position is determined, draw the line design according to S4.

[0056] Preferably, S4 comprises the following steps: S4.1, obtain the diameter of the tail tube of the tail shaft at the tail end of the three-tail shaft system from the turbine professional, and give it on the cross-section, longitudinal section and waterline; obtain the gearbox installation size from the turbine professional, sketch the width on the center line of the shaft system in the cross-section, and this width is determined by the gearbox width + the width of the cabin solid rib plate + the appropriate gap. Based on this width, give each waterline half-width point one by one, and connect the points into a line to make the cross-section line a smooth teardrop shape; S4.2, after the cross-section line of the gearbox position is drawn, the three-tail cross-section sketches of each station are drawn backward and forward. According to the sketch, the initial smoothing is first performed from the water surface, and the continuation is continued after completion; S4.3, the transverse section of the reference ship type line, according to the main dimension width of the new ship, comprehensively consider the midship transverse section area to draw the new ship midship transverse section line with large outer drift and large round bilge, draw the bow closure transverse section line at the bow, and draw the stern closure plate line at the stern. After completion, according to the bow and midship transverse sections and the three stern sketch trends, give the transverse section lines of each station one by one; S4.4, after the sketch of each station is completed, continue to draw the downward convex large arc tunnel top line of the tunnel top between the three tails of each station, and draw the imitation vortex tail line with shallow vortex grooves on both sides of the top of each single tail body according to experience and reference to the model ship, and connect it with each single tail of the side and three tails to obtain the preliminary complete super-baseline three tail line; S4.5, the bow lines of the reference ship are drawn in combination with the width and depth of the new ship for optimization and transformation. The drawing principle is a large longitudinal bow and a large arc V-shaped cross-section bow line that is convex downward; S4.6, after the above sketches are completed, preliminary smoothing is performed on the AutoCAD software, and the lines of the three-tail super-baseline, large external drift, and large longitudinal bow inland passenger and vehicle ship are copied to the HD-SHM hull line system software for fine smoothing, so that the preliminary line drawing is obtained; S4.7, perform statics and performance calculations, and make appropriate optimizations based on the statics calculation results until the design requirements are met; S4.8, perform CFD simulation calculations, further optimize, and iterate the calculations until the requirements of various design indicators are met; S4.9, after CFD simulation calculations meet the requirements, model tests shall be carried out. Ship model tests shall apply for on-site verification by China Classification Society, with the goal of obtaining the green ship class III standard for ro-ro passenger ships.

[0057] Preferably, the appropriate optimization in S4.7 includes the optimization of the longitudinal position of the center of buoyancy and displacement.

[0058] Embodiment 2: See Figure 1 It is a diagram of a 121m passenger and ro-ro ship in the Chuanjiang River. Figure 2 Figures (a) and (b) are the free surface wave diagrams of the 121m passenger and ro-ro ship in the Chuanjiang River obtained by CFD simulation calculation, from which the direction of hull form optimization can be obtained. Figure 1

[0059] From Figure 2 Figures (a) and (b) show the free surface waves at two ship speeds. It can be seen from the figures that when Vs = 23 km / h, the free surface wave-making is relatively obvious. And the wave crest at the bow is relatively high, having a certain optimization space.

[0060] Figure 3 See It is the distribution diagram of the surface pressure coefficient at the stern of the 121m passenger and ro-ro ship in the Chuanjiang River obtained by CFD simulation calculation, from which the detailed optimization position direction can be obtained.

[0061] Figure 3 See The distribution of the hull surface pressure coefficient at the stern at two ship speeds is given. It can be seen that the pressure coefficient distributions are very similar and in line with the physical reality. It can be seen from the 23 km / h stern oblique view that after the tail shaft is pressed down, the transition with the hull is not smooth enough, and pressure non-uniform areas are generated at the end of the flat bottom (the red circle in the figure) and in front of the area where the shaft is pressed down (the blue circle in the figure). The transition between the two can be made smoother to make the pressure distribution more uniform, thereby improving the speed performance.

[0062] Figure 4 See It is the longitudinal section hull form diagram of the 121m passenger and ro-ro ship designed by the present invention.

[0063] Figure 5 See The waterplane hull form diagram of the 121m passenger and ro-ro ship in the Chuanjiang River.

[0064] Figure 6 See The transverse section hull form diagram of the 121m passenger and ro-ro ship in the Chuanjiang River.

[0065] Figure 7 In order to verify the performance of the above-mentioned 121m passenger and ro-ro ship in the Chuanjiang River, a corresponding ship model towing tank test was carried out on it. For the specific test results, see The speed prediction curve diagram of the 121m passenger and ro-ro ship model towing tank test with D = 3m.

[0066] At the same time, Table 1 is obtained, which is the prediction results of the self-propulsion factor and efficiency components of the actual ship when D = 3.3m.

[0067] Table 1 Prediction results of the self-propulsion factor and efficiency components of the actual ship when D = 3.3m ​

[0068] See Table 2 for the offsets table for CCS plan review after optimization.

[0069] Table 2 Offsets Table of the 121m Passenger-RoRo Ship on the Chuanjiang River after Optimization

[0070] See Figure 8 - Figure 17 General arrangement plan of the 121m truck roll-on / roll-off ship on the Chuanjiang River.

[0071] Figure 8 Side view of the 121m truck roll-on / roll-off ship on the Chuanjiang River; Figure 9 Main deck plan of the 121m truck roll-on / roll-off ship on the Chuanjiang River after loading; Figure 10 Main deck plan of the 121m truck roll-on / roll-off ship on the Chuanjiang River; Figure 11 Upper deck plan of the 121m truck roll-on / roll-off ship on the Chuanjiang River; Figure 12 Boat deck of the 121m truck roll-on / roll-off ship on the Chuanjiang River; Figure 13 Bridge deck plan of the 121m truck roll-on / roll-off ship on the Chuanjiang River; Figure 14 Canopy deck plan of the 121m truck roll-on / roll-off ship on the Chuanjiang River; Figure 15 Front view below the upper deck of the 121m truck roll-on / roll-off ship on the Chuanjiang River; Figure 16 For Figure 15 A-A view of the 121m truck roll-on / roll-off ship on the Chuanjiang River; Figure 17 Bilge plan of the 121m truck roll-on / roll-off ship on the Chuanjiang River.

[0072] Example 3: In this example, a 130m passenger-roll-on / roll-off ship on the Chuanjiang River is provided.

[0073] See Figure 18 Longitudinal section lines plan of the 130m passenger-roll-on / roll-off ship on the Chuanjiang River; Figure 19 Waterplane lines plan of the 130m passenger-roll-on / roll-off ship on the Chuanjiang River; Figure 20 Transverse section lines plan of the 130m passenger-roll-on / roll-off ship on the Chuanjiang River.

[0074] Example 4: For the parent ship "Lines Plan of the 60-Car Passenger-RoRo Ship on the Chuanjiang River" to prove that the present invention is an innovative invention based on the parent ship. Figure 21 Longitudinal section lines plan of the 60-car passenger-roll-on / roll-off ship on the Chuanjiang River, proving that the three tails of the parent ship do not exceed the baseline.

[0075] Figure 22 Waterplane lines plan of the 60-car passenger-roll-on / roll-off ship on the Chuanjiang River, proving that the tunnel between the three tails is concave upward.

[0076] Figure 23 Transverse section lines plan of the 60-car passenger-roll-on / roll-off ship on the Chuanjiang River, proving that the three tails do not exceed the baseline.

Claims

1. A hull form for an inland river ro-ro passenger ship, characterized in that, The hull form adopts a three-tail form line beyond the baseline. A propeller is provided at the end of the three tails. The three tails beyond the baseline form a slender and smooth water-drop-shaped cross-sectional line in the height direction, enabling sufficient oncoming flow in front of the propeller. The three tails beyond the baseline are used to reduce the height of the propeller shafting centerline, increasing the radius from the propeller to the ship bottom plate, so as to adopt a large-diameter propeller to improve the propeller propulsion efficiency. At the same time, the three tails beyond the baseline make each individual tail fin form a slender water-drop-shaped cross-sectional line, making it slender and smooth in the height direction.

2. The hull form of an inland river ro-ro passenger ship according to claim 1, characterized in that: The three tails beyond the baseline extend forward to the engine room section. The tops of the two tunnels between the left and right tails and the middle tail are designed as downward-convex large-arc cross-sections, and through repeated optimization and iterative CFD simulation calculations, the tunnel top form line is obtained, thereby making the water flow smooth and the pressure distribution uniform.

3. The hull form of an inland river ro-ro passenger ship according to claim 1, characterized in that: At the position where each single tail fin installs a gearbox or an electric motor in the engine room section, based on the characteristic of the reduction of the propeller shafting centerline, the lower half of the gearbox or the electric motor is installed downward beyond the baseline to reduce the ship's center of gravity and achieve an optimized layout of the engine room equipment space in the height direction.

4. The hull form of an inland river ro-ro passenger ship according to claim 1, characterized in that: Both sides of the top of each single tail are designed as vortex-like tails with shallow vortex grooves, maximizing the height of the cross-sectional line of each single tail and achieving a more abundant oncoming flow in front of the propeller.

5. The ship form of the hull line for an inland river passenger and ro-ro ship according to claim 1, characterized in that: The two sides adopt a cross-sectional line with a large outward flare to obtain sufficient deck area with a small displacement.

6. The hull form of an inland river ro-ro passenger ship according to claim 1, characterized in that: The large longitudinal flow bow adopts a longitudinal mid-section line with a small inflow angle and a downward-convex U-shaped arc cross-section line. Through CDF simulation calculations, the pressure distribution at the bow is uniform and the resistance is reduced.

7. The hull form of an inland river ro-ro passenger ship according to claim 1, characterized in that: The hull form is further optimized and designed with the existing main hull form in the Chuanjiang ro-ro market, the "Chuanjiang 60-car cargo vehicle ro-ro ship", as the parent hull form.

8. The hull line design method for the hull line of an inland river ro-ro passenger ship according to any one of claims 1-7, characterized in that, Determine the main dimensions of the ship and use CAD drawing software to draw the grid lines of the longitudinal section and the waterline cross-section; Specifically, it includes the following steps: S1. Draw the three-view contour lines of the ship length, ship width, and molded depth, and combine with the general arrangement plan to draw the position lines of each cabin; S2. According to the marine engineering specialty, draw the rudder system centerline, the half-width, height, and propeller installation position of the shafting centerline on the drawing; S3. Determine the longitudinal position where the gearbox or the electric motor is located according to the engine room layout. After determining the position, proceed with the form line design and drawing according to S4.

9. The hull line design method for the hull line of an inland river ro-ro passenger ship according to claim 8, characterized in that, S4 includes the following steps: S4.

1. Obtain the diameter of the tail shaft and tail pipe of the marine engineering specialty at the outlet of the three-tail shafting at the end, and give it on the cross-sectional view, longitudinal section, and waterline; Obtain the gearbox installation dimensions from the marine engineering specialty and sketch the width on the shafting centerline of the cross-sectional view. This width is determined by the gearbox width + the width of the engine room solid floor + a suitable gap. Based on this width, give each waterline half-width point one by one, and connect the points to form a smooth water-drop-shaped cross-sectional line; S4.

2. After the cross-sectional line of the gearbox position is drawn, then draw the sketches of the three-tail cross-sectional lines of each station backward and forward. According to the sketches, first perform primary fairing from the water surface, and wait for the continuation after completion; S4.

3. With reference to the cross-section line of the reference hull form, considering the main dimension width of the new ship, a new ship midship cross-section line with large flare and large round bilge is drawn by comprehensively considering the midship cross-sectional area. The forward end plate cross-section line is drawn at the bow, and the aft end plate line is drawn at the stern. After completion, according to the trends of the bow, midship cross-section and three-screw draft sketches, the cross-section lines of each station are successively given; S4.

4. After the sketches of each station are completed, continue to supplement and draw the large arc tunnel top line that bulges downward from the top of the three-screw tunnel between each station. On both sides of the top of each single-screw blade, according to experience and referring to the reference hull form, a vortex-like stern line with a shallow vortex groove is drawn, and at the same time, it is smoothly connected to the side and each single-screw of the three-screw to obtain a preliminary complete three-screw type line above the baseline; S4.

5. The bow hull form of the reference hull form is combined with the width and depth of the new ship for optimization and transformation. The drawing principle is a large longitudinal flow bow and a downward convex large arc V-shaped cross-section bow hull form; S4.

6. After the above sketches are completed, preliminary fairing is carried out on the AutoCAD software. The three-screw above the baseline, large flare, and large longitudinal flow bow inland ro-ro passenger ship hull form are copied to the HD-SHM hull line system software for fine fairing. Thus, a preliminary hull form drawing is obtained; S4.

7. Perform hydrostatic and performance calculations, and make appropriate optimizations according to the hydrostatic calculation results until the design requirements are met; S4.

8. Perform CFD simulation calculations, further optimize, and perform iterative calculations repeatedly until all the target indicators of the design task are met; S4.

9. After the CFD simulation calculations meet the requirements, a model test is carried out. The ship model test should apply for on-site verification by the China Classification Society, aiming to obtain the standard of a green ship class III for ro-ro passenger ships.

10. The hull line design method for the hull line of an inland river ro-ro passenger ship according to claim 9, characterized in that, The appropriate optimization in S4.7 includes the optimization of the longitudinal position of the center of buoyancy and displacement.

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