JP2005088627A - Shape of bow of single hull type sea navigation vessel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fresh and original shape of a bow in a single hull type high speed vessel, the hull being capable of plunging into waves. <P>SOLUTION: The tip end (13) of the bow is provided at the position near the waterline (30) in the vertical direction compared to a deck (15). The upper portion of the bow is composed of top surfaces (11) longitudinally elongating from the tip end (13) of the bow up to the height of the deck located in back of the tip end (13). The top surfaces are tilted downward from a vertical plane passing the center line of the hull in the lateral direction of the hull. At least half of the area of the top surfaces is configured such that any longitudinal tangents of the top surface at any points on the area have an inclination angle within the range from 0° to 30° with respect to the horizontal direction, and any lateral tangents of the top surface at any points on the lateral cross section of the area have an inclination angle within the range from 0° to 30° with respect to the horizontal direction, and the projected area of the top surfaces on the horizontal plane is at least 5% of the projected area of the vessel on the horizontal plane. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a bow shape of a single-hull type marine navigation ship, and in particular, instead of the traditional traditional bow deck shape, it has a plurality of inclined top surfaces and does not advance the wave on the hull, but rather the hull. It is related to a novel and novel bow shape in a single-bore type high-speed ship that can be pushed into the waves.

  When a ship navigates in waves (high waves), vertical acceleration acting on the ship (hereinafter simply referred to as “up / down acceleration” or simply “acceleration”) cannot be avoided. In traditional traditional bows, the longitudinal cross-sectional shape is the widest on the deck, but the bow of such a cross-sectional shape is lifted because of its large volume when passing the wave front (wave top), and then the wave It tends to move to fall in the valley.

  Such movement is generally referred to as pitching and is greatly amplified under certain conditions, causing vertical acceleration. In extreme cases, when certain conditions such as ship speed, hull length, and wave height are combined, the hull may move up from the surface of the water and move into the water in response.

  The laws and regulations governing the structural design of the ship require a sufficiently high-strength structure that supports the hull outer shell, and therefore a heavy structure, in order to prevent damage to the hull due to the above-described movement. The requirement for structural strength can be relaxed under the hull structure regulations only if the overall load due to acceleration and the local load due to slamming can be reduced. In other words, these loads can only be reduced by reducing the adverse effects on the hull caused by waves.

  The benefits associated with lighter hull structures are enormous. First, the materials required for purchase and assembly are reduced, and the construction cost of the ship can be reduced. Secondly, a lighter ship can get the required speed with a small engine output, the engine to be purchased needs a small output, and less fuel is consumed while the engine is running. The cost of building and operating such a ship can also be reduced. Lastly, when the vertical acceleration acting on the ship is reduced, the damage to the cargo is reduced, passengers' seasickness is reduced, and the incidence of severe seasickness is reduced. This will directly and significantly increase the potential for ship profits. In addition, certain vessels, such as passenger ferries and crew carriers for transfers to offshore oil rigs, are often restricted by weather, but these benefits are even more pronounced for such vessels. .

  Also, under stormy weather, the ship is reduced in speed and forced to change course, increasing the operating cost of the ship. In some cases, ship operations may not be permitted due to current or anticipated sea conditions.

  In response to the above-mentioned problems, various ships have been proposed that are designed to reduce the adverse effects on the hull, particularly due to the movement of waves, and to reduce vertical pitch and decrease vertical acceleration. Known solutions fall into two main categories: passive navigation control and active navigation control.

The former method is based on the shape of a hull, generally a multi-hull type hull (see Patent Document 1, Patent Document 2, etc.). The latter method is an attempt to minimize the vertical movement of the hull by means of a mechanically actuated and computer-controlled movable surface, generally a hydrofoil (fin) (Patent Document 3, Patent Document 4, Patent). Reference 5, Patent Document 6, etc.). However, both are expensive to purchase and use.
US Pat. No. 5,184,561 US Pat. No. 5,263,433 US Pat. No. 6,116,180 UK Patent Application No. 2150890 JP-A-4-169393 JP 7-132875 A

  More specifically, in a multi-hull type ship, two hulls are connected by a heavy deck, so the ratio of the loaded weight to the total hull weight is the lowest. This multi-hulled ship is a catamaran ship with a twin-hull, a trimaran ship with two stability hulls on both sides of the main hull, or a large torpedo that is completely submerged with relatively thin vertical hydrofoil. It is one of the SWATH (Small Waterplane Area Twin Hull) based on the hull where the hull of the mold is connected to the deck, and these are pushed by the relatively small volume of seawater when passing through the crest of the wave, The effect of waves on ship behavior is minimized.

  A multi-hull type ship is actually effective, but its effectiveness is up to a certain wave height. At higher wave heights, the two elongate hulls hardly function to damp up and down movements, so waves begin to hit the deck that extends between the hulls, often having a worse impact than normal monohulls. In addition, this multihull type ship always incurs high costs for a sufficiently obvious reason. In other words, when building a complex multihull type ship with a heavy connecting deck that needs to accommodate all loads, when building a wide monohull that can accommodate loads in the hull. Compared to the high cost.

  Although an active navigation control device is effective, there is not only an increase in purchase costs but also a problem of increased risks. In other words, in order for a movable hydrofoil to operate properly, the hydrofoil needs to be completely submerged in water, exposing it to the risk of colliding with other objects, including ice blocks and large fish and mammals. Will be. There are reports that movable hydrofoil was damaged or made unusable by a slight collision without affecting the hull itself. In many cases, the ship is designed to be inoperable without the active navigation control device described above, which may make the ship inoperable and require assistance.

  In addition, since the water flow is necessary to make the movable hydrofoil function in the navigation control device, for example, when the ship is moving slowly or stopped, as is often the case when maneuvering around a quay or offshore facilities. If this is the case, the movable hydrofoil tends to lose its effect and has its limitations.

  As a result, it can be said that the most cost-effective offshore navigation structure remains a single hull, ie a single hull. To date, attempts to reduce ship movement in the waves have been documented by an elongated monohull hull or a well-known wave penetrating bow (a wave penetrating bow). It is designed by a single hull. The former adheres to the principle that the adverse effects of waves can be mitigated by making the hull much longer than the length of the waves, which is clearly expensive to build. The length of the hull not only increases costs, but among many other factors, it is a factor particularly related to structural strength, and a long hull is much heavier than a short hull.

  The latter has a bow shaped like a substantially circular needle, is limited to a very elongated hull and is designed to be completely unaffected by waves.

  In view of the above-mentioned conventional problems, the present invention is novel in a single-body high-speed ship having one or more inclined top surfaces and capable of thrusting the hull into the waves rather than on the waves. It is an object to provide a novel bow shape.

  Therefore, the bow shape of the single-hull type marine navigation ship according to the present invention is such that the bow tip is provided at a position closer to the draft line than the deck in the vertical direction, and the upper part of the bow extends in the front-rear direction from the bow tip to the rear deck height. The top surface is inclined with a downward inclination in a direction transverse to the both sides of the hull from a vertical plane passing through the center line of the hull, and at least half of the area of the top surface is above the region. The tangent line in the front-rear direction at any of the above points forms an angle within the range of 0 degrees or more and 30 degrees or less with respect to the horizontal direction, and the tangent line in the width direction at any point on the widthwise longitudinal section of the above region However, the projected area of the top surface on the horizontal plane is 5% or more of the projected area of the ship on the horizontal plane.

  The present invention seeks to eliminate or mitigate the adverse effects of waves on the hull by a completely different approach than conventional methods. The basic idea of the present invention is clearly different from the bow shape of other existing ships, and by generating a dynamic drag that suppresses the force that causes the pitching motion in the waves, The bow shape which reduces the pitching motion of the hull of the ship which is navigating at high speed is provided.

  The pitching of the ship can be reduced by a new bow shape that allows the wave to deliberately break through the wave rather than proceeding over the wave. In general, the movement of the ship is not the center of the cross-sectional shape of the bow in the normal sailing state, but the center of the cross-sectional shape of the bow is not located higher than the water surface like the bow of a traditional ship. Is realized by the bow formed so as to be located near the water surface.

  The wave penetrating bow itself is not new. Wave penetrating bows have been the subject of extensive research worldwide in recent years, but should not be confused with the early impingement bows attached to warships and colliding with enemy ships. The early wave penetration type bow is attached to a multihull type ship (basically a catamaran ship or a catamaran ship) that is still frequently operated, but it is larger than the traditional bow waterline. It is designed based on the idea of suppressing the pitching motion by reducing the volume, and is sized optimally.

  There is a record of sporadic research on the wave-passing bow on monohulls, but none has been put into practical use at the time of filing this application. The main reason for the impediment to practical use is that it is difficult to maintain the restoration performance of a monohull with a wave penetration type bow in the waves. Simply put, the volume above the waterline has the desirable effect of preventing the hull from being submerged below the surface of the water, but at the same time it also causes the bow to be lifted high above the waves, often resulting in This leads to an undesirable phenomenon of crashing into the waves.

  Research to date on monohull wave penetration bows reduces not only the undesirable phenomena described above but also the desired effects by reducing the volume of the bow on the waterline. Such a hull will not be lifted or collide with the waves, but will easily be submerged. In the case of a catamaran vessel, the above problem can be solved by providing a third bow between the two main wave penetration hulls. In the case of a monohull, such a third bow cannot be provided.

  The present invention not only simply reduces the volume of the bow that causes the pitching motion, but also attempts to solve the above-mentioned problems by taking the step further and devising its shape. In other words, by balancing the lift and drag (downward lift) generated by the interaction between the hull and the waves, the movement of the hull can be dynamically controlled and the pitching motion can be reduced. A new shape and volume allocation are proposed.

  In the present invention, the main feature of improving the hydrodynamic performance is that, in the navigation direction of the ship, the top surface constituting the upper part of the bow as viewed from above forms a general wedge shape facing forward. It is in the way of combination. This top surface is inclined further downward in the longitudinal section in a direction transverse to the bow in the width direction, and forms a shallow inverted V shape (for example, “Λ” shape). At their rear tops, the top surface is further curved outward so that the water and splashes on the deck and wheelhouse are repelled sideways.

  A further advantage of the present invention is that it can reduce the resistance at high speeds on calm water, and thus the engine power, compared to a normal forward tilted bow. The tip of the wave penetration type bow of the present invention is located close to the waterline, and as a result, the waterline length (hull length at the water surface) is the waterline length of the same length hull with a standard bow. Longer than Hydrodynamically, a long hull with the same amount of drainage will surely require less engine power to travel on calm water at the same speed.

  The above-mentioned effects can be said for all the wave penetration type bows. However, wave penetrating bows developed so far tend to be very long and thin, and as a result, the total length of the hull becomes long, which increases the cost of ship construction. The idea of the present invention attempts to produce the required hydrodynamic effects without increasing the overall length. In fact, in order to construct a bow top surface that generates drag, the new bow of the present invention must be formed relatively wide, so that the hull has a useful space inside and a narrow bow. More than the traditional high-speed navigation ship type.

  In addition, the fact that the load of the hull acceleration and wave collision can be reduced means that the designer can instruct to reduce the internal structure by installing the new wave penetrating bow of the present invention when building the ship. Means. Weight is one of the most important factors affecting cargo ship economics. Simply put, if the ship is lighter in design, more cargo can be transported by the same ship, and economic profits can be increased. Regarding structural strength and safety measures, there are the minimum structural strength required for ships to navigate the ocean, and the minimum safety measures required by accredited agencies by respecting the laws and regulations. The classification society confirms and approves the design before the ship is built.

  The high-speed ship, which is an application of the new wave penetration type bow of the present invention, has a structure inside the hull according to a standard called High Speed Craft (HSC) high-speed boat standard. Under HSC standards, structural dimensions (thickness of hull skin and stiffener dimensions) depend mainly on the acceleration of the ship and the load at impact. In other words, these values are measured for high speed ships and are based on empirically determined maximum loads, which inevitably require a heavy structure.

  Lightweight construction is permitted only if the load on the hull proves to be smaller by model testing. Lightweight construction not only leads to lower construction costs, but also means lower engine power for the same speed and load conditions. This difference in hull weight can be replaced by more cargo and economic benefits. This weight reduction is a basic effect of the present invention.

  The inventor has been involved in a comprehensive research and development program that includes the design of lightweight structures and model comparison tests between a wave-piercing bow and a standard bow in the same hull. In this basic research and development, the effect of the present invention was fully confirmed.

  The ship's bow shape described above creates a uniqueness and an improved mindset. This bow makes good use of the waves to stabilize the hull during high-speed navigation, resulting in reduced hull acceleration, lighter structure, lower required output, reduced investment and operating costs, This will increase the amount of cargo that can be mounted and high profits.

  At least half of the area of the top surface constituting the upper part of the bow is such that the tangent line in the front-rear direction at any point on the region forms an angle within the range of 0 degrees to 30 degrees with respect to the horizontal direction. It is important that the tangent line in the width direction at any point on the vertical cross section in the width direction forms an angle in the range of 0 degrees to 30 degrees with respect to the horizontal direction. This is because when the angle formed by the tangent line with respect to the horizontal direction exceeds 30 degrees, it is difficult to obtain a drag force that balances the lift due to the waves, and it is difficult to ensure the restoration performance of the ship in the waves. When the area of the area that satisfies the above angle condition is less than half the area of the top surface that constitutes the upper part of the bow, in order to obtain a drag that balances the lift due to the wave, and the stability of the ship in the wave This is because it is necessary to form a large top surface that constitutes the upper portion of the bow.

  Also, if the top surface constituting the upper part of the bow is too small, a drag that balances the lift cannot be obtained. The magnitude of the drag generated on the top surface depends on the navigation speed of the ship, and it is necessary to reduce the top surface in the case of a high-speed navigation vessel, while it is necessary to increase the top surface in the case of a low-speed navigation vessel. There is. According to the experiments of the present inventors, the projected area on the horizontal plane of the top surface needs to be 5% or more of the projected area on the horizontal plane of the ship, and in the case of a normal ship, an area of about 10% is preferable. It was confirmed.

  The tip of the bow only needs to be set at a position closer to the water line than the height of the deck. For example, in the case of a ship having a total length of 20 m to 50 m, it can be set to a height of about 0 m to 1.5 m when viewed from the water line.

  Even if the top surface of the upper part of the bow is shaped differently on the port and starboard, it is also possible to ensure the right and left balance of the ship by setting the tangential angle in the front and rear direction or the width direction well on the port and starboard However, from the viewpoint of hull design, it is preferable to secure the left and right balance of the ship by making the top surface constituting the upper portion of the bow symmetrical on the port and starboard.

  Although the top surface which comprises the upper part of a bow may be comprised with one panel, you may be comprised with the some panel divided by the ridgeline.

  Moreover, the center in the width direction of the top surface constituting the upper part of the bow may be a ridge line defining the panel, and a flat or curved panel is further provided in the center in the width direction of the top surface so as to extend in the front-rear direction. Even if it does, there exists an above-mentioned effect of this invention.

  Even if the top surface constituting the upper part of the bow is entirely or partially formed into a conical curved surface shape, a planar shape, or a curved surface shape, the above-described effects of the present invention can be obtained.

  Furthermore, one or a plurality of step portions may be formed on the top surface constituting the bow upper portion so as to extend in the width direction or the front-rear direction of the ship. However, if the step becomes high, it becomes resistance to the flow of water and splashes that have moved along the top surface, and there is a risk that the desired drag may not be obtained, so the height of each step is the total length of the top surface. The size should be less than 10%. In addition, if the inclination of the vertical surface of the step portion with respect to the vertical direction increases, the drag generated at that portion increases and adversely affects the original drag generated at the top surface. Is preferably an angle within a range not exceeding 45 degrees from the vertical plane.

  Further, instead of the stepped portion, one or a plurality of concave grooves may be formed on the top surface constituting the bow upper portion so as to extend in the width direction or the front-rear direction of the ship. However, if the width of the groove is increased, resistance to the flow of water and splashes that have moved along the top surface and a desired drag may not be obtained. Therefore, the width of the groove is 10% of the total length of the top surface. Desirably, the dimension is less than%.

  One or more recesses may be provided in the top surface that constitutes the upper portion of the bow to accommodate mooring fixtures and other hardware and / or fittings.

  Hereinafter, the present invention will be described in detail based on specific examples shown in the drawings. 1 to 5 show a preferred embodiment of a single trunk type marine navigation ship according to the present invention. In addition, this invention is not limited to the example shown by a figure, A various change and improvement are possible.

  In the figure, the tip 13 of the bow of the hull 10 is set at a position closer to the water line 30 than the deck 15 in the vertical direction, for example, a position of 0 m to 1.5 m when viewed from the water line 30, and the upper part of the bow is the tip of the bow. 13 is composed of a top surface 11 extending with an inclination so as to increase rearward, and a rear portion of the top surface 11 is curved concavely below the deck 15 and extends to the height of the rear deck 15, and the top surface. 11 is formed so that the projected area on the horizontal plane is approximately 10% of the projected area on the horizontal plane of the entire ship.

  At least half of the area of the top surface 11 is such that the longitudinal tangent line at any point on the region has an angle in the range of 0 degrees or more and 30 degrees or less with respect to the horizontal direction, or on the longitudinal cross section of the region. The tangent line in the width direction at any point forms an angle within the range of 0 degrees or more and 30 degrees or less with respect to the horizontal direction, and the upward lift generated when water is pushed away by the volume below the draft line 30 by rushing the hull into waves It is a drag generation surface that generates a drag that balances with.

  Also, the portion curved below the deck 15 behind the top surface 11 is a splash reflecting portion 12 that repels the water or the flow of splashed water moving along the top surface 11 toward the side away from the hull. It has become.

  Further, the top surface 11 of the bow is composed of two panels defined by ridge lines and has a symmetrical shape on the port side and starboard side, and the top surface 11 extends from the vertical plane passing through the center line of the hull to the side of the hull. (See the dotted line 16 in FIG. 5), and as a result, the bow top surface 11 has a substantially inverted V-shaped wedge shape as viewed from above.

  In the above example, most of the top surface 11 of the bow has a flat shape, but all or a part of the top surface 11 may be formed in a conical curved surface shape whose diameter increases from the tip toward the rear. Further, all or part of the top surface 11 constituting the upper part of the bow can be formed in a planar shape or a curved surface shape. Moreover, the top surface 11 can be provided with one or a plurality of recesses to accommodate mooring tools and other metal fittings and fittings.

  An important and innovative feature that has not been used in the design of single-hulls that navigate the ocean at high speeds is the force generated by the drag generating surface 11, that is, a plurality of panels, that drains the lower volume of the bow waterline 30. (The force that typically causes pitching by lifting the bow over the wave when the bow enters the wave) It is the top surface 11 of the new wave penetration type bow of this invention.

  FIGS. 1 to 5 show the schematic shape of the top surface 11. The top surface 11 is selected in accordance with the size, shape and angle of the ship according to the size of the ship and the design speed. The force generated by the drainage is canceled when pushing through, minimizing the pitching motion.

  In addition, by adopting the opposite top surface 11, the force causing the pitching motion is offset, and the load affecting the pitching motion and the structural weight required by law is reduced. Significant improvements in the technical field will be obtained.

  As a result of the bow tip 13 being lowered to a position closer to the draft line 30 compared to the normal bow tip 21, the draft length L2 is the same overall length shown in FIG. 2 (a) as shown in FIG. 2 (b). Therefore, it becomes longer than the draft line length L1 of a ship having a normal bow. The resistance of the ship's hull and the output required to navigate the hull at the required speed are in principle an inverse function of the length of the draft line.For example, in the case of the same hull and the same amount of drainage, the draft line length is long. The resistance and output become smaller. The increased length of the waterline is a unique feature of the present invention and suggests a very large improvement in the field of ship design.

  It must be admitted that the effects of the present invention can be offset with respect to the adverse effects of water and droplets carried on the bow of sailing while navigating in the waves rather than overcoming the waves. As expected in earlier experiments, the total amount of water and splashes drained by the wave-piercing hull bow is less than that of the hull with a normal bow, but the normal hull thrusts into the waves. Water and splashes are drained away from the hull, whereas in wave-wound bows, water and splashes jump over the bow and fall to the rear deck where loads and machinery can be mounted. It was confirmed. This undesired phenomenon can be suppressed by the curved splash reflecting portion 12 behind the reverse top surface 11, and the splash reflecting portion 12 separates water that has slid up the top surface 11 away from the hull center line. It is designed to bounce to the side as you go. The above undesirable phenomenon can be further suppressed by the ship operator reducing the navigation speed of the ship, especially when severe sea conditions are encountered.

It is a schematic perspective view which shows preferable embodiment of the single trunk type marine navigation ship provided with the wave conventional type bow which concerns on this invention. It is a side view which compares and shows the bow (b) in the said embodiment, and the conventional bow (a). It is a principal part side view which shows the shape of the bow in the said embodiment. It is a principal part top view which shows the shape of the bow in the said embodiment. It is a principal part front view which shows the shape of the bow in the said embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Hull 11 Top surface 12 Splash reflection part 13 Bow tip 14 Hull superstructure 15 Deck 16 Typical vertical cross-sectional shape of a bow 20 Normal ship deck 21 Normal ship bow tip 30 Waterline

Claims (10)

The bow tip is positioned closer to the draft line than the deck in the vertical direction. Inclined with a downward slope in a direction crossing from the surface to both sides of the hull,
At least half of the area of the top surface is such that the tangent line in the front-rear direction at any point on the region forms an angle in the range of 0 degrees or more and 30 degrees or less with respect to the horizontal direction, and the widthwise longitudinal section of the region While the tangent line in the width direction at any of the above points forms an angle within the range of 0 degrees or more and 30 degrees or less with respect to the horizontal direction,
A bow shape of a single-body marine navigation ship, wherein a projected area of the top surface on a horizontal plane is 5% or more of a projected area of the ship on a horizontal plane. 2. The bow shape of a single-hull marine navigation ship according to claim 1, wherein the top surface constituting the upper portion of the bow has a symmetrical shape on the port and starboard. 3. The bow shape of a single trunk type marine navigation ship according to claim 1 or 2, wherein a top surface constituting the bow upper part is composed of a plurality of panels defined by ridge lines. 4. A single-hull marine navigation according to claim 1, further comprising a flat or curved panel extending in the front-rear direction at the center in the width direction of the top surface constituting the bow upper part. Ship bow shape. The bow shape of a single trunk type marine navigation ship according to any one of claims 1 to 4, wherein all or part of the top surface constituting the bow upper part is formed in a conical curved surface shape. 5. The bow shape of a single trunk marine navigation ship according to any one of claims 1 to 4, wherein all or part of a top surface constituting the bow upper portion is formed in a planar shape or a curved shape. A step is formed on the top surface constituting the bow upper portion, the height of the step is less than 10% of the total length of the top surface, and the angle of the vertical surface of the step with respect to the vertical direction. The bow shape of a single trunk type marine navigation ship according to any one of claims 1 to 6, wherein is an angle within a range not exceeding 45 degrees from a vertical plane. A single-drum type according to any one of claims 1 to 6, wherein a concave groove is formed on a top surface constituting the bow upper portion, and the width of the concave groove is less than 10% of the total length of the top surface. The bow shape of a marine vessel. The rear end portion of the top surface constituting the upper portion of the bow is further curved in a concave shape below the deck, so that the flow of water and splashes moving along the top surface is laterally moved away from the hull. The bow shape of the single-hull type marine navigation ship according to any one of claims 1 to 8, wherein the bow is rebounded. 10. A single-hull type ocean according to any one of claims 1 to 9, wherein a top surface constituting the bow upper part is provided with one or a plurality of recesses for receiving a mooring tool and other metal fittings and / or fittings. The bow shape of sailing vessels.

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