JPH0745419Y2 - The lower hull of a composite support type super high speed ship - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] This invention relates to an ultra-high-speed ship that travels at a speed of 40 to 50 knots or more, and more specifically, relates to the lift of a hydrofoil and the lower hull (lower hull or lower hull). Also referred to as submerged body) relates to the shape of the lower hull of a composite-supported ultra-high-speed ship of the type supported by both buoyancy.

[Conventional technology]

In recent years, as needs for speeding up various means of transportation by land, sea, and air have increased, passenger ship routes such as inland seas and remote islands have not been overlooked.
A major period of change is approaching with the aim of improving services that emphasize comfort and speed. Recently, even in Japan, an ultra-high-speed passenger ship, which supports the entire weight of the hull at high speeds and travels at ultra-high speeds by water jet propulsion, has appeared to meet the needs of the passenger sector.

In the field of freight-only transportation, the need for ultra-high-speed processing is also increasing significantly in order to deliver large amounts of perishable food products (vegetables, seafood, etc.) and electronic components to demand areas on the same day (the same day). There is. Conventionally, such perishable products are often treated as air cargo mainly in the case of mass transportation in order to prevent deterioration of freshness, but even with an airplane dedicated to freight, the transportation weight is at most about tens of tons, It is not able to cope with the recent trend of mass cargo movement.

On the other hand, in recent years, precision equipment parts such as electronic parts are produced in countries such as Southeast Asia and Taiwan, which have low labor costs, and are relatively close to Japan. It has become to. In this case, in order to reduce the amount of the inventory as much as possible for the convenience of management, there is a strong demand for timely acquisition of the required amount of the parts required for the production of such electronic device parts at that time.

However, conventional high-speed freight (container) vessels cannot handle the above-mentioned demands for large-volume and ultra-high-speed transportation because it takes too many days to transport them, and when they are transported by air, there are weight restrictions and transportation costs. However, the cost is high and the production cost is affected.

Even if an ultra-high-speed cargo ship of the same type as the above-mentioned ultra-high-speed passenger ship is adopted, the type in which the weight of the hull is entirely supported by the lift of the hydrofoil will naturally limit the amount of load. For example, if a freighter with a loading capacity of several hundred tons is designed with this type of ship, huge hydrofoils will be required, and it is said that this is not feasible.

Therefore, conventionally, as shown in FIG. 10 (a) side view and FIG. 10 (b) front view, the hull is composed of an upper hull 1 and a lower hull 2, and struts 3 are fixed between the front and rear of the hull. A multi-support type ship in which hydrofoils 4 are provided on both sides of the lower hull 2 is proposed (for example, Japanese Patent Laid-Open No. 61-5).
4382 gazette, see U.S.A. 55-102693 gazette). here,
The composite support type is a type of ship that supports the weight of the hull by both the buoyancy of the lower hull 2 and the lift of the hydrofoil 4 when traveling at ultra-high speed. That, in this composite support type super high speed craft, FIG. 10 (a), the low speed as shown in (b) run Wataru in Kissui of d ₂ where the lower the upper hull 1 is submerged in the water (hereinafter,
This coastal run state) called "boat run", it emerged by lift hydrofoil 4 becomes ultrafast, run Wataru in Kissui of d ₁ (the coastal run state hereinafter referred to as "Tsubasahashi") to.

By the way, the shape of the lower hull 2 is generally considered to be an axisymmetric body as a whole (Japanese Patent Laid-Open Nos. 61-54382 and 61-54382).
61-46785, JP-A-61-46787).

[Problems to be solved by the device]

However, when the lower hull 2 is formed of an axisymmetric body, the head side tends to sink downward as the speed increases when sailing at an ultra-high speed as intended by the present invention. (The tendency to head down) becomes remarkable. If this tendency is not so great, it is not impossible to control (correct) using a control mechanism such as the hydrofoil 4, but essentially, the shape of the lower hull 2 is improved and the It is preferable to eliminate or reduce the tendency.

That is, as described above, when the lower hull 2 basically has the above-described shape, the control using the control mechanism such as the hydrofoil 4 must be a control in which its characteristics are taken into consideration. However, in general, a very complicated control corresponding to the characteristic of the above tendency that changes with speed must be performed. In particular, when winging in waves that significantly change due to the weather at that time, the above tendency also changes due to the influence of various waves, etc., and it is extremely complicated control to automatically respond to this change. You will be forced.

In view of the above tendency of the lower hull when wing-running at an ultra-high speed as described above, the present invention keeps the hull resistance value generated in the lower hull along with the wing running below a predetermined value and maintains the buoyancy above a predetermined value.
An object of the present invention is to provide a lower hull of an ultra-high-speed ship that does not cause the bow of the lower hull to sink downward as described above even at an extremely high speed.

[Means for Solving the Problems]

In order to achieve the above purpose, the hull consists of an upper hull and a lower hull, and the entire hull is submerged during ultra-high speed navigation.The upper hull is supported by both the buoyancy of the lower hull and the lift of the hydrofoil. In a multi-support type ultra-high-speed ship that supports on the surface of water, the upper hull and the lower hull are connected to each other by a plurality of columnar struts with wing-shaped cross-sections at separate positions, and the entire lower hull is submerged. The bottom surface side of the bow portion of the bow is compared to the downward warp of the top surface side of the bow portion with respect to the center line of the hull (refers to the line formed by connecting the centers of the sections. And a large upward warp (including a warp or a part of which is formed in a planar shape; the same in this specification), and a rounded corner portion of the upper surface of the lower hull. It is characterized by having done.

[Action]

By configuring as described above, the pressure distribution on the bottom side of the bow of the lower hull during ultra-high speed navigation is
Since it is higher than that of the above-mentioned axisymmetric body (see FIGS. 10 (a) and 10 (b)), an upward force acts and the downward moment around the midship generated from the bow (also referred to as the head-down moment) The tendency of the bow to sink downward when the lower hull is submerged in a submerged state can be significantly reduced or eliminated. The moment around the midship is a value obtained by multiplying the pressure acting on each part by the distance from the part to the midship.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a composite support type ultra high-speed ship equipped with a lower hull according to the present invention as seen from the bottom direction, FIG. 2 is a perspective view of the same from above, and FIG. 3 is a bow portion of the lower hull. FIG. 4 is a partial side view showing a water line, and FIG. 4 is a partial plan view of the bow portion of the lower hull.

In FIG. 1, 1 is an upper hull, 2 is a lower hull that is submerged during navigation, 3 is a strut that connects the upper hull 1 and the lower hull 2, and 4 is an underwater attached to a side portion of the lower hull 2. Wings, 4A is a flap attached to the hydrofoil 4, and 5 is a water jet jet for propulsion.

As shown in FIG. 1, the composite-support type hull is mainly connected to an upper hull 1, struts 3 having wing-shaped cross-sections arranged at the center of the bottom of the hull, and lower ends of the struts 3 at the front and rear. It comprises a lower hull 2 having a length substantially the same as that of the upper hull 1, and hydrofoils 4 projecting substantially horizontally on both sides at the strut position of the lower hull 2. The hydrofoil 4 has a plurality of flaps 4A for controlling the attitude of the hull and the like.
Are attached respectively. While the boat is running, water is sucked from a suction port (not shown) provided near the lower end of the rear strut 3 and a water jet jet port 5 provided at the stern end.
It is designed to jet at a higher speed and the hull will obtain forward thrust.

Then, in the multi-support type ultra-high-speed ship having the above-mentioned configuration, when the super-high speed ship is sailing, the buoyancy of the lower hull 2 and the lift of the hydrofoil 4 in which the upper hull 1 is submerged. It floats above the surface of the water and runs (wings).

The lower hull 2 which is the subject of the present invention is, as shown in FIG. 3, FIG. 1, or FIG.
The side 2a is formed so as to have a large upward warp with respect to the centerline O (see FIG. 3) of the hull, as compared with the downward warp on the upper surface 2b side of the bow 2A. That is, in the case of this embodiment, the upper surface 2b of the bow 2A is substantially horizontal, and the bottom surface 2a
Is designed to warp upward with a large curvature.
Therefore, in the bow portion 2A of the lower hull 2, the center line O (see FIG. 3) is eccentric upward.

In the case of the present embodiment, the upward warp of the bottom surface 2a generally begins near the front edge of the front strut 3.

In the above embodiment, the warped surface is formed by a line having a large curvature, but it may be formed by a flat surface. In that case, the connection portion with another surface is curved (R-shaped). It is desirable to process so that Further, in the present embodiment, the stern 2B portion of the lower hull 2 is formed in a fin-like shape composed of a vertical plane as if it were a fin of a fish, for the purpose of improving straightness in a horizontal plane. Further, as shown in FIG. 5 (c), the upper surface of the lower hull 2 is formed so that the corners of the upper surface are round (the corners are so-called "rounded").

Thus, in this manner, the bottom 2a of the bow 2A of the lower hull 2 with respect to the center line O of the hull is the upper surface 2b of the bow 2A.
The pressure distribution on the bottom side of the bow of the lower hull 2 at the bottom side of the lower hull 2 during ultra-high speed traveling is larger than that of the lower side of the lower hull 2 as shown in FIG. It becomes higher than that of the axisymmetric body shown in (d) (or FIGS. 10 (a) and (b)), and as a result,
Due to a decrease in the downward moment around the midship of the lower hull 2 (referred to as a head-down moment) generated from the bow, an upward moment around the midship of the lower hull 2 is generated from the bow 2A. .
As a result, the tendency of the bow of the lower hull to sink downward can be significantly reduced even when the lower hull travels at an ultrahigh speed in a submerged state.

In order to confirm the above-mentioned effects, the present inventor has confirmed that a lower hull model (see FIGS. 5 (a) to (d)) having a bow portion similar to the lower hull shown in FIGS. , A model of a lower hull consisting of an axisymmetric body (see FIGS. 6 (a) to (d)), and conversely, downward bow of the upper surface side with respect to the center line of the hull at the bow portion is higher than the bottom surface side. An aquarium experiment was conducted using a model of the lower hull that was larger than the warp (Figs. 7 (a) to (d)).

In the above model, FIG. 7 (a) shown as a reference example.
Except for the model shown in (d), the stern side is not formed like fins.

Further, each of the above models is formed so that the entire volume (volume) of the lower hull becomes equal.

Furthermore, this experiment is a dimensionless value obtained by dividing the distance f from the center line O of the lower hull 2 to the water surface L by the thickness D of the lower hull, as shown in FIG. In order to clarify the relationship of), the submersion depth is compared as a parameter as shown in FIG.

That is, in the case of the bow shape according to the present invention, the trim angle of the lower hull is set to "0" as shown in FIG. 9 in which the moment coefficient of the lower hull submerged on the vertical axis is taken. When run, the value of "head down moment""C _M1 " (9th
(Refer to the figure) is about “0.05 × 10 ⁻³ ”, which is close to “0”, whereas in the case of the axisymmetric bodies shown in FIGS. Moment value "C _M2 " (9th
(Refer to the figure) is about 0.2 x 10 ^-3, which is quite large. Further, conversely, in the case of the models shown in FIGS. 7 (a) to 7 (d), the value of "head-down moment""C _M3 " (9th
(See the figure) is even larger, about 0.25 × 0.30 × 10 ^-3 . From this, it is understood that eccentricity of the center line of the bow portion of the lower hull upward is very effective for "eliminating the head-down moment".

By further shifting the point of eccentricity of the center line of the bow portion of the lower hull upward to the stern side, the above "head-down moment" is further reduced as compared with the model of the lower hull used in this experiment ("0 It turned out that it can be done.

By the way, the moment coefficient around the midship of the lower hull Is Is represented by. With this formula, Is the moment around the midship, ρ is the density of the traveling liquid, L is the length of the lower hull, and V is the traveling speed.

In FIG. 9, the moment coefficient when the trim angle is inclined up and down by 2 degrees is also described. When the trim angle is inclined up by 2 degrees, the bow is lowered downward.
Some moments (moment coefficient) approach "0" or become larger than "0". However, when the trim angle is added in this way, the hull resistance value increases compared to when the trim angle is not added. It is not an advantageous solution.

Further, when the submersion depth is made smaller, the influence from the water surface becomes larger, and the above “head-down” moment tends to become larger than when the submersion depth is large. Therefore, it is understood that the submergence depth above a certain level is necessary.

[Effect of device]

As described above, according to the present invention, since the bow shape of the lower hull is configured as described above in the composite support type ultra-high speed ship, the lower hull tends to sink downward even when traveling at ultra high speed. Can be eliminated or significantly reduced.

As a result, the control of the composite-supported ultra-high-speed ship during sailing is greatly reduced. As a result, the control is simplified and the reliability regarding the traveling stability is improved. Further, similarly, by simplifying the control, the control relationship having a large weight in terms of price becomes cheap, and the implementation of the ultra-high speed ship can be promoted.

Therefore, the present invention greatly contributes to the realization of a large-scale ultra-high-speed ship, which has been difficult in the past.

[Brief description of drawings]

FIG. 1 is a perspective view of a composite-supported ultra-high-speed ship according to the present invention as seen from the bottom of the ship, FIG. 2 is a perspective view of the same from above the lower hull, and FIG. 3 is also a bow of the lower hull. FIG. 4 is a plan view showing the shape of a model of the lower hull according to the present invention. FIG. 5 (a) is a plan view showing the shape of the lower hull according to the present invention. FIG. 5B is a side view showing the shape of the model with a water line and a line indicating a section, and FIG. 5C is the right side of the section in the line showing each section shown in FIG. 5B. FIG. 5 (d) is a sectional view taken along each water line shown in FIG. 5 (b), and FIG. 6 (a)-
(D) and FIGS. 7 (a) to 7 (d) show the above-mentioned FIG. 5 (a) to FIG. 5 (a) in a model in which the lower hull has an axisymmetric body and in a model in which the upper surface of the bow has a greater warp than the bottom.
Similar to (d), FIG. 8 is a diagram for explaining the submersion depth, showing the thickness (depth) of the lower hull and the relationship between the lower hull and the water surface, and FIG. 9 is the performance of the lower hull according to the present invention. FIG. 10 (a) and FIG. 10 (b) are explanatory diagrams of a conventional composite-support type ship, in which FIG. 10 is a moment diagram showing a comparison with a lower hull having a bow of another shape. 1 ... Upper hull, 2 ... Lower hull, 2A ... Bow, 2a ...
… Bottom of the bow, 2b …… Top of the bow, O …… Center line of the lower hull.

Claims (1)

[Scope of utility model registration request] 1. A hull composed of an upper hull and a lower hull, which is entirely submerged during ultra-high speed traveling. The upper hull is brought above the water surface by both the buoyancy of the lower hull and the lift of the hydrofoil. In a composite support type ultra-high-speed ship that is supported by the above, the upper hull and the lower hull are connected by a plurality of columnar struts with wing-shaped cross-sections at separate locations, and the bow of the lower hull in which the entire body is submerged. The bottom side of the hull is formed to have a large upward warp with respect to the centerline of the hull as compared to the downward warp of the upper side of the bow, and the corners of the upper surface of the lower hull are rounded. The lower hull of a composite support type ultra-high speed ship, characterized in that