JPS625109B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a catamaran, and more particularly to a catamaran for high-speed navigation.

Conventional catamarans include those shown in Figures 1 to 8. Figures 1 and 4 are hull side views, Figures 2 and 4 are hull side views,
Figure 5 is a front view of the hull, Figures 3 and 6 are shape diagrams showing cross sections at various positions on the starboard side of the hull, and Figures 7 and 8 are line diagrams showing the distribution of the cross-sectional area of the hull below the water surface in the longitudinal direction of the hull. It is.

Reference numeral 1 in Figures 1 to 8 indicates the upper hull, 2a, 2b
3a, 3b are the lower hull, 4a is the propeller, 5a is the rudder, 6 is the baseline, 7 is the planned waterline, 8 is the front perpendicular, 9 is the rear perpendicular, 10 is the hull superstructure, 11a, 11b are the 12a is the engine room, 12a is the engine, 13a is the shaft, 14 is the distribution curve of the cross-sectional area of the lower hull, 15 is the distribution curve of the cross-sectional area of the underwater part of the strut, and 16 is the distribution curve of the cross-sectional area of the underwater part of the hull. It shows. The suffix a indicates a member on the starboard side, and the subscript b indicates a member on the port side.

The boat shown in Figures 1 to 3 is called a semi-submerged catamaran, in which the width of the struts 2a and 2b is narrower than that of the lower hull 3a and 3b, and the width (or diameter) of the lower hull is usually smaller than that of the lower hull. It is 1/2 or less.

The front and rear ends of the lower hulls 3a, 3b are constricted into a streamlined shape, and a propeller 4a is provided at the rear end (not only on the starboard side but also on the port side, although not shown).

The front end of the strut is also constricted in a streamlined shape, and the rear end extends beyond the propeller to the rear, and the rudder 5a is attached to the lower surface (not only on the starboard side but also on the port side (not shown)). also).

Fig. 3 a, b, and c are respectively a- of Fig. 1.
A, bb and cc cross-sectional shapes are shown.

By reducing the water line area of the struts 2a and 2b that penetrate the water line 7 in this way, it is possible to reduce the wave forcing force applied to the ship's hull when the ship navigates in waves. It has the characteristic that the movement in waves becomes smaller.

However, since the width of the struts of semi-submerged catamarans is very narrow, it is difficult to mount the engine on the lower hull and struts. Engine rooms 11a and 11b are provided, and an engine 12a is installed therein (not only on the starboard side, but also on the port side, although not shown), and a shaft 13a runs from this to the propeller 4a (not only on the starboard side, but also on the port side). Although not shown, the port side is also connected.

Therefore, not only does the structure of the shaft system that connects the engine and propeller become extremely complicated, but also because the engine rooms 11a and 11b are arranged on the upper hull 1,
There are various other problems, such as the difficulty in utilizing the large deck area that characterizes catamarans, and the noise and vibrations from the engine room affecting the adjacent superstructure of the hull.

Figures 4 to 6 are intended to solve the above-mentioned problems with the semi-submerged ship, by widening the width of the struts 2a and 2b near the center of the ship until they are equal to the width of the lower hull 3a and 3b. An engine 12a is housed in a lower hull 3a and a strut 2a. Although not shown, the same applies to the port side.

As a result, the waterline area near the center of the hull increases, but by appropriately thinning the waterline shape of the front and rear struts 2a and 2b, the semi-submerged catamaran shown in Figs. It is known that it can be made into a catamaran with almost the same performance in waves.

FIG. 6 shows changes in this cross-sectional shape (starboard side) in the longitudinal direction. However, a, b, c, d, e in Fig. 6 are respectively a-a, bb, c-c, d- in Fig. 4.
d, shows the cross-sectional shape of ee.

In this way, this hull type (hereinafter referred to as a modified semi-submerged catamaran) solves the problems of the semi-submerged catamaran mentioned above, and allows for effective use of a large deck area. Since the hull superstructure 10 is sufficiently far away from the engine 12a, it is not affected by engine noise and vibration, the shaft 13a can be easily arranged, and the hull structure itself can be simplified, among other advantages. I have it.

As mentioned above, the modified semi-submerged catamaran has excellent features, but compared to a normal semi-submerged catamaran,
The disadvantage is that the hull resistance increases in the Froude number range of 0.4 to 0.6 and at high speeds exceeding this range.

This is thought to be due to the fact that the water line shape of the struts 2a, 2b of the half-submerged catamaran greatly changes in the longitudinal direction of the ship.

Now, if we calculate the longitudinal distribution of the hull cross-sectional area below the planned waterline of 7 for a semi-submerged catamaran and a modified half-submerged catamaran, the results will be as shown in Figures 7 and 8, respectively. Here, line 14 shows the distribution of the cross-sectional area of the lower hulls 3a and 3b, line 15 shows the distribution of the cross-sectional area of the struts 2a and 2b below the designed waterline 7, and line 16 is the sum of the two, showing the distribution of the cross-sectional area of the lower hulls 3a and 3b below the designed waterline 7. Shows the distribution of the total cross-sectional area of the hull.

In addition, in Figure 8, lines 14 and 15 are at the center of the ship.
The reason why they match is that the cross-sectional areas of the lower hulls 3a, 3b at the center of the hull and the struts 2a, 2b happen to match in the examples shown in FIGS.

As is clear from comparing line 16 in Figures 7 and 8, there is a large change in the cross-sectional area of the half-submerged catamaran in Figure 8, which causes complex wave-making interference in the high-speed range. It can be seen that this causes an increase in resistance.

The present invention takes advantage of the characteristics of a half-submerged catamaran that allows the engine to be mounted on the strut and lower hull, while reducing resistance in the high-speed range (Froude number 0.4 to 0.6 or higher). The aim is to provide a catamaran with improved performance.

Therefore, the high-speed catamaran of the present invention is a catamaran in which a pair of left and right lower hulls below the water surface and an upper hull above the water surface are connected by a pair of left and right struts penetrating the water surface. In order to house the engine inside the strut and the lower hull, the strut includes:
The cross-sectional area of the engine accommodating part is formed to be larger than the cross-sectional area of the engine accommodating part before and after the engine accommodating part, and the distribution of the total cross-sectional area of the above-mentioned struts and the lower hull below the waterline in the longitudinal direction is It is characterized by being set almost flat over the front and back of the section.

That is, the present invention changes the hull cross-sectional area distribution of the half-submerged catamaran by changing the cross-sectional shape of the lower hulls 3a and 3b. It was designed to be close to .

Although they are collectively referred to as high-speed catamarans here,
The present invention is applied to multihulls having two or more lower hulls and used in high speed ranges (Froude number 0.4 to 0.6 or higher).

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 9 to 12 show the first embodiment of the invention, FIGS. 13, 15, and 16 show the second embodiment of the invention, and FIGS. , 17 and 18 show a third embodiment of the present invention.

Figure 9 is a diagram showing the distribution of the cross-sectional area in the longitudinal direction of the hull, Figures 10, 13, and 14 are side views of the hull, Figures 11, 15, and 17 are front views of the hull, and Figures 1
Figures 2, 16, and 18 are sectional views showing the cross-sectional shape at each position on the ship's starboard side;
Figures a, b, c, d, and e in Figures 16 and 18 are those in Figures 10, 13, and 14, respectively.
XIIa-XIIa, XIIb-XIIb, XIIc-XIIc, XIId-X
II
d, XIIe-XIIe and a-a, b-
b, c-c, dd, e
-e, a-a, bb,
c-c, d-d, e-
The shape of the cross section at point e is shown.

The symbols in Figures 9 to 18 are almost the same as those shown in the explanation of the conventional technology mentioned above, and the newly added numbers are 3Ma and 3Mb for the central part of the lower hull, and 3Fa and 3Fb for the lower part. Forward part of the hull (part with a larger cross-sectional area than the central part of the hull, 3 Ma, 3 Mb)
3Aa and 3Ab indicate the rear part of the lower hull (portion with a larger cross-sectional area than the central part of the hull 3Ma and 3Mb), but the reference numeral 3Ab is omitted from illustration.

First, regarding the first embodiment of the present invention,
0, 11, and 12, in this catamaran, the struts 2a, 2b are located at the center of the hull so that the hull propulsion engines 12a, 12b can be accommodated inside the struts 2a, 2b and the lower hulls 3a, 3b. The cross-sectional area of the engine accommodating portion is larger than the cross-sectional area of the front and rear portions of the engine accommodating portion.
(See line 15 in Fig. 9) In addition, in this catamaran, the cross-sectional area of the lower hulls 3a and 3b is compared with the center part of the hull where the engine housing section is located, as shown by line 14 in Fig. 9. It is increased in the forward and aft parts, and as a result, the distribution in the longitudinal direction of the total cross-sectional area of the struts 2a, 2b and the lower hulls 3a, 3b below the waterline is
As shown by line 16 in FIG. 9, it is set as flat as possible except for the front and rear ends.

In this first embodiment, the cross-sectional area of the lower hull is allowed to increase uniformly in the front and rear portions in the circumferential direction, and FIGS. 10 to 12 show a side view, a front view, and a sectional view, respectively. As a result of uniformly increasing the cross-sectional area of the lower hull in the circumferential direction, the front and rear [3
Fa, 3Fb and 3Aa, 3Ab], the hull hangs down below the baseline 6, respectively.

Generally, the increase in cross-sectional area at the front and rear of the lower hull is only about 20 to 30% of that at the center of the hull.
Therefore, if the lower hull cross section is circular, the increase in radius will be about 10 to 15% of the midship area.

The shape of the water line of the struts 2a and 2b is lens-like with a thin front and rear shape, which reduces the water line area to keep vibration during waves to a minimum, and increases the width of the strut in the central engine housing part. While making it possible to accommodate the engine below,
By setting the distribution of the total cross-sectional area (cross-sectional area of the hull below the water surface) in the longitudinal direction to be flat across the engine housing area and a considerable range before and behind it, it is possible to reduce the hull resistance in the high-speed range. There is.

Next, regarding the second embodiment of the present invention, the ninth and first
3, 15, and 16, in the first embodiment, the cross-sectional area of the lower hulls 3a and 3b was uniformly increased in the circumferential direction, whereas in the second embodiment, the cross-sectional area of the lower hulls 3a and 3b was expanded only in the lateral direction. , the shape is not changed in the vertical direction.

Although the effects are almost the same as in the first embodiment, this embodiment has the advantage that the hull does not sag below the baseline 6.

Furthermore, regarding the third embodiment of the present invention, the ninth,
14, 17, and 18, the first and second
In the embodiment, the width of the lower hull 3Ma, 3Mb and the width of the struts 2a, 2b are the same at the center of the hull, but in this embodiment, the width of the struts 2a, 2b is
The lower hull is 3 Ma, as long as it can accommodate a.
The width is narrower than 3Mb.

In other respects, the structure is the same as that of the first embodiment, and substantially the same effects as those of the first embodiment can be obtained.

As detailed above, according to the high-speed catamaran of the present invention, a pair of left and right lower hulls below the water surface and an upper hull above the water surface are connected by a pair of left and right struts penetrating the water surface. In the hull ship, in order to accommodate the hull propulsion engine inside the above-mentioned support and the lower hull, the above-mentioned support is formed such that the cross-sectional area of the engine-accommodating portion thereof is larger than the cross-sectional area of the engine-accommodating portion before and after the engine-accommodating portion. The engine can be housed in the lower part of the hull with a simple structure in which the distribution of the total cross-sectional area of the above-mentioned struts and the lower hull below the waterline in the longitudinal direction is set to be almost flat across the above-mentioned engine accommodation area and its front and back. As,
This has the advantage of reducing hull resistance at high speeds while reducing the impact of engine noise and vibration on the hull superstructure.

[Brief explanation of the drawing]

Figures 1 to 3 show conventional catamarans.
The figure is a side view, Figure 2 is a front view, Figure 3 a, b, and c are a-a, b of Figure 1, respectively.
-b and c-c are starboard side sectional views, and Figs. 4 to 6 show other conventional catamarans, Fig. 4 is its side view, Fig. 5 is its front view,
Figure 6 a, b, c, d, e are a-a, bb, c-c, dd of Figure 4, respectively.
and a starboard side sectional view at ee,
Figure 7 is a graph showing the longitudinal distribution of the hull cross-sectional area below the planned waterline of the catamarans shown in Figures 1 to 3;
Figure 8 is a graph showing the longitudinal distribution of the hull cross-sectional area below the planned waterline of the catamarans shown in Figures 4 to 6;
FIG. 9 is a graph showing the longitudinal distribution of the hull cross-sectional area below the planned waterline of the catamaran according to the present invention;
10 to 12 show a high-speed catamaran as a first embodiment of the present invention, and FIG. 10 is a side view thereof;
Figure 11 is its front view, Figure 12 a, b, c,
d and e are XIIa-XIIa and XIIb- in Figure 10, respectively.
XIIb, XIIc-XIIc, XIId-XIId and XIIe-XII
e
FIG. 13 is a side view of a high-speed catamaran as a second embodiment of the present invention, and FIG.
Figure 4 is a side view of a high-speed catamaran as a third embodiment of the present invention, Figure 15 is a front view of the high-speed catamaran of Figure 13, and Figures 16 a, b, c, d, and e. are a-a, bb-b, respectively in Fig. 13.
c-c, dd and e-
Fig. 17 is a front view of the high-speed catamaran in Fig. 14, Fig. 18 a,
b, c, d, e are a-a in Fig. 14,
b-b, c-c, d-
d and ee are starboard side cross-sectional views. 1... Upper hull, 2a, 2b... Support, 3a,
3b...lower hull, 4a...starboard side propeller,
5a... Starboard side rudder, 3Aa... Rear part of lower hull, 3Fa, 3Fb... Forward part of lower hull, 3
Ma, 3Mb...Middle part of lower hull, 6...Baseline, 7...Planned waterline, 8...Fore perpendicular,
9... Rear perpendicular line, 10... Hull superstructure, 11
a, 11b...engine room, 12a...engine on starboard side, 13a...(propeller) shaft on starboard side, 14
... Distribution curve of the cross-sectional area of the lower hull, 15 ... Distribution curve of the cross-sectional area of the underwater part of the strut, 16 ...
Distribution curve of the cross-sectional area of the underwater part of the hull.

Claims (1)

[Claims] 1. In a catamaran consisting of a pair of left and right lower hulls below the water surface and an upper hull above the water surface, connected by a pair of left and right struts penetrating the water surface, the hull propulsion engine is connected to the interior of the struts and the lower hull. In order to house the engine, the strut is formed so that the cross-sectional area of the engine housing portion thereof is larger than the cross-sectional area of the front and rear of the engine housing portion, and the total cross-sectional area of the strut and the lower hull below the waterline is larger in the longitudinal direction. A high-speed catamaran, characterized in that the distribution of the engine accommodating portion is substantially flat in the engine accommodating portion and before and after the engine accommodating portion.