JPS59195494A - Semi-submerged catamaran - Google Patents

Abstract

PURPOSE:To make the distribution of wake uniform for providing a steering force sufficient to steer a ship and as well to reduce underwater noise due to propeller sunds, by providing a retractable rudder device in the bottom of a submerged body carrying a propeller, and as well by positioning the rear end of the submerged body, being sufficiently apart from the rear end of a strut. CONSTITUTION:A semi-submerged catamaran has a submerged body 3 disposed below a strut 2 and formed in an axially symetrical long and narrow topede- like shape whose rear end part carrying a propeller projects by a distance E from the rear end of the strut 2. With this arrangement, the propeller 4 is positioned being sufficiently apart from the rear end of the strut 2. A rudder device 5 which is positioned forward of the rear end of the strut 2, may project from the bottom of the submerged body 3, and may also retract into the latter.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semi-submersible catamaran that can make the flow 4J as uniform as possible and reduce underwater noise caused by propellers.

Conventionally, in a general semi-submersible catamaran, as shown in Fig. 1, the rudder device 1 is installed immediately after the propeller 4 installed at the rear end of the submerged body B installed at the bottom of the strut 2. By using the wake of the propeller, the direct rudder pressure increases, which is effective in terms of maneuverability.

However, in order to minimize the noise caused by underwater propeller noise, which is required in recent years for ships and the like, it is necessary to minimize the non-uniformity of the wake on the propeller disk surface caused by the wake of struts and the like. For this reason, it is necessary to keep the rear end of the strand 2 sufficiently far away from the propeller 4 to make the wake more uniform. If the wake distribution in the case of the conventional semi-submerged catamaran shown in Fig. 1 is shown in Fig. 2-A, the semi-submerged body 6 By protruding into an elongated, axisymmetric valve shape, it is possible to achieve a uniform wake distribution in the radial direction of the propeller, as shown in Fig. 2-B. Under such a good wake distribution, the wake of the propeller 4 is almost constant over the entire circumference on the same radius, so the propeller S
・：(As the / is rotated, there is little change in the operating condition.
Fluctuations in lift force, etc. are also sufficiently small, cavitation is less likely to occur than in the case of the wake distribution shown in Fig. 2-A, and therefore propeller vibration and noise are also reduced.

However, in this case, as described above, although the wake distribution is improved, there is a problem in that the arrangement of the rudder device 1 shown in FIG. 1 becomes difficult. Therefore, it is realistic to place the rudder in front of the propeller, but in this case, as with the strut, the rudder must be placed sufficiently away from the propeller disk surface so as not to impair the uniformity of the wake. It won't happen.

However, if the rudder is placed below the submerged body, the maximum swamp will further increase in semi-submersible catamarans, which tend to have deep swamps, which is undesirable from the viewpoint of the water depth of the port.

Therefore, the present invention aims to provide sufficient rudder force and low underwater noise performance for maneuvering the vessel during high-speed cruising by arranging the υ1 type rudder device in a position that does not impair the uniform wake distribution as described above. The purpose of this design was to provide a semi-submersible catamaran that was equipped with both sides of the ship. A major feature of semi-submersible catamarans is that they can be maneuvered well, so there are no problems with maneuvering when entering port.

That is, the semi-submersible catamaran of the present invention is a semi-submersible catamaran equipped with a propeller at the rear end of a submerged body provided at the bottom of a strut, in which the rear end of the strut and the propeller are connected. The rear end of the submerged body is formed to protrude from the rear section 61 of the strut into an elongated, axisymmetric valve shape, and the submerged body is positioned sufficiently forward of the rear end of the strut. It is constructed by providing a rudder device that can protrude from the bottom of the submerged body and that can be retracted into the submerged body.

An embodiment of the present invention will be described below with reference to the drawings. FIG. This is a 3° plan cross-sectional view of the main part of the submerged body of this semi-submerged catamaran. First, this semi-submerged catamaran is equipped with a propeller 4 at the rear end of the submerged body 3 provided at the bottom of the strut 2.
The rear end of the submerged body A is connected to the rear end of the strut 2 by a distance of 1
The shape of the valve is slender and axially symmetrical, such as a torpedo shape with a protruding shape, and the I part and the propeller 4 are positioned at the rear of the cyst jet 2 and sufficiently in front of the propeller 4.

Note that it is effective to make the distance IE as long as possible in order to form the ideal uniform wake distribution shown in Fig. 2-13, but the length of the semi-submersible catamaran, It is very important to take into account major points such as sluggish water, the speed of the ship to be used, 1/) construction problems, and other factors when making decisions.

Next, in this semi-submersible catamaran, the rudder device and l-5 are placed in a position forward of the rear end of the strut 2, as shown in Figures 3 and 4. i3J protruding from the bottom
It is arranged so that it can be inserted into the submerged body 3. .

This rudder device 5 is provided in the middle of a transmission shaft 7 that connects two main engines 6 and a propeller 4 in a submerged body 6 shown in FIG.
It can be stored in the storage space 8, which has the same function as the fin stabilizer that has been widely used in the past. Furthermore, any type of retracting and protruding method of the A'e device 5 may be used. In a semi-submersible catamaran, the rudder device 5 is provided in front of the rear end of the strut 2.
If this rudder device 5 is placed between the rear 1"la portion of the strut 2 and the propeller 4 and above the submerged object,
In this case, the wake of the strut 2 may cause poor steering, and noise may be caused by vortices and bubbles generated on the free surface during steering.
It is also known that vibrations occur and are not convenient.

In addition, when navigating at low speed and in places with shallow water lines such as in ports,
By retracting the rudder device 5, the ship can be sufficiently maneuvered by the thrust difference between the left and right propellers 4 of the twin hull without using the rudder, and the rudder device 5 can be used only in sufficiently deep places.

Therefore, in the semi-submersible catamaran of the present invention, the rear end of the submerged body equipped with a propeller is located sufficiently far from the rear end of the strut, so that the wake distribution can be made uniform. Can you do it, Popera? It is possible to reduce the underwater mist caused by the spear, and also to reduce the occurrence of cavitation.Furthermore, as described above, it is possible to provide a rudder device having a sufficient rudder area for maneuvering the ship while making the wake distribution uniform.

[Brief explanation of the drawing]

Figure 1 is a side view of the main parts of a conventional semi-submersible catamaran, Figure 2-A
The figure is in Figure 1, -! 1! Wake distribution diagram in a submersible catamaran, Figure 2-B is an improved wake distribution diagram, and Figure 3 is a side view of essential parts of a semi-submersible catamaran in an embodiment of the present invention. , FIG. 4 is a plan cross-sectional view of the main part of the submerged body in FIG. 3. 2... Strut, 6... Submerged body, 4 river propeller,
5... Rudder device. Agent: Patent Attorney Makoto Ogawa − Patent Attorney: Ken Noguchi Patent Attorney: Kazuhiko Saishita

Claims (1)

[Claims] In a semi-submersible catamaran equipped with a propeller at the rear end of a submerged body provided at the bottom of a strut, the rear end of the submerged body A1 is installed so that the rear end of the strut and the propeller are pre-separated from each other. , is formed to protrude from the rear end of the strut in an elongated, axis-symmetrical valve shape, and is capable of protruding from the bottom of the submerged body at the front force position of the rear end of the strut, and is capable of protruding from the bottom of the submerged body. A semi-submersible catamaran characterized by being equipped with a rudder device that can be retracted into the body of water.