JPS6061389A - Vessel having reduced wave making resistance - Google Patents

Abstract

PURPOSE:To reduce the wave making resistance at the bow by forming a water guide path from the bow to the stern while providing a propeller in said path and guiding the wave from the bow to the stern. CONSTITUTION:A water guide path 10 is formed under the hull from the bow 11 to the stern 12. While a propeller 3 coupled with a drive mechanism 4 is arranged in said path 10. With such arrangement, wave is led to the stern thus to prevent disturbed flow at the stern and to reduce the wave making resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a boat having a boat shape that can avoid the generation of wave-making resistance.

When an object floating on the water surface moves, waves are generally generated on the water surface, unless the moving speed is extremely slow. This is because the energy used to move an object is released in the form of waves, and this phenomenon is unavoidable in the propulsion of conventional boat-shaped vessels.

This is called wave-making resistance, and the present invention has devised a ship shape that does not generate it at all.

The mechanism of wave-making resistance generated by ships can be explained as shown in Figures 1 and 2.

When the hull floating on the water moves in the direction of the arrow, the water on the front side in the direction of travel is forcibly moved to both sides by the hull ■, and the water on the rear side fills the space left behind by the hull ■. Because of this, a large amount of water flows into both sides and the rear of the ship.

If the ship is moving very slowly, the water flowing in front of and behind the ship's hull will be able to flow without much disturbance, but if it moves quickly, the water in front will not have time to move to both sides, so the
As shown in the figure, a mass of water is formed on the water surface in front of the ship's hull. Then, due to the action of gravity, it splits into two sides of the ship,
It generates waves.

On the other hand, on the rear side of the ship, water from the surrounding area is not flowing in enough time to fill the space after the hull has moved, so a hollow space is created on the water surface. Naturally, water flows into this space with great force from the surrounding area, creating strong turbulence.

In this way, the bulge in the water surface that occurs at the front of the hull (1) and the depression in the water surface that occurs at the rear of the ship act as a force that strongly resists the propulsion force of the ship.

In order to suppress the occurrence of this resistance, the following method is used. That is, the method is to eliminate the bulge of water that occurs at the front of the ship in FIG. 2 by creating a depression in the water surface that occurs at the rear of the ship.

The shape of the high lead is shown in Figure 3.

The hull (■) has a waterway in the middle, and a propulsion propeller (■) driven by the prime mover (■) is installed in the middle of the waterway. In Figure 3 (
A) is a plan view, (b) is an A-A sectional view, and (c) is the first entrance from B.

Now, with the hull ■ fixed, rotate the propeller ■,
Considering the case where water flows in the direction of the arrow, water flows into the entrance side waterway ■ as if being sucked in from the front of the hull ■,
It is thought that the water will flow out to the rear of the ship as if being discharged from the exit channel.

At that time, as shown in the cross-sectional view of (B), the water level in the inlet side channel becomes lower than the outside water level ■, and on the contrary, the water level in the outlet side is higher than the external water surface ■.

Therefore, if the hull ■ moves forward in the direction of the arrow ■ due to the thrust received by the propeller ■, even if the water in front of the hull ■ enters the waterway ■, the water surface will not rise. , the water surface on the rear side of the hull ■ will not be dented by water discharged from the waterway. In other words, this ship shape does not have any elements that generate waves.

This principle is the same for the structure shown in FIG.

FIG. 4(a) shows a cross section taken along line DD of (Io), and FIG. 4(b) shows the first opening seen from the front side C of (a).

When the hull ■ moves in the direction of the arrow (ヰ) due to the thrust generated by the propeller ■, the swelling of the water surface that should have occurred at the front is absorbed by the suction side waterway ■, and the water surface that should have formed on the rear side disappears. The depression will be solved by the water discharged from the outlet waterway.

Therefore, even in the hull shape shown in Figure 4, there is no element that generates waves. However, what is important here is that in the case of Figure 3, also in the case of Figure 4.
In the case of the figure, the shape of the ship is the same on the water inlet side (for example, in the case of Figure 4, the shaded part (B)) is the same as the shape on the outlet side, and in which cross section of the hull must be the same. In other words, there must be no change in the cross-section of the hull, taken along a plane perpendicular to the water flow, in the part of the hull that goes below the water surface.

This is because the cross-sectional area increases in the middle as shown in Figure 5 (a), or the I
This is because if there is a reduced part like P), an element that generates wave-making resistance will be created in that part.

The present invention has significant advantages in the following two respects.

(1) The energy saving effect is extremely large.

The two major resistances associated with ship navigation are wave-making resistance and frictional resistance between water and air, and since one of the wave-making resistances can theoretically be reduced to almost nothing, it is possible to reduce the ship's resistance accordingly. The energy used for propulsion can be saved, resulting in a large energy saving effect.

(2) It becomes possible to design a ship with stable navigation.

In conventional ship shape theory, a streamlined shape is inevitable, so in a single hull design, it was impossible to increase speed by making the width relatively large compared to the length. For this reason, high-speed ships have a narrow hull shape, and in order to maintain the stability of the ship, it is necessary to design a ship that limits the amount of cargo or rigging equipment. By designing a ship with a double-row waterway as shown in the figure, the relationship between ship speed and hull width can be made irrelevant, the amount of cargo to be loaded can be dramatically increased, and the limitations of rigging equipment can be reduced. Even if it is relaxed, a hull can be created that allows stable navigation against rolling, etc.

[Brief explanation of the drawing]

Figure 1 shows the movement of the ship and the state of water flow Figure 2 shows the state of the water surface as the ship moves Figure 3 (A)
Cross-sectional view on plane A-A of plan view (b) (a) (c) Cross-section on plane D-D of (a) (b) Figure (b) @
(a) Diagram of the hull where the cross-sectional area increases midway (b)
Figure 6: A diagram of the hull where the cross-sectional area decreases midway.(A) Plan view (B) First time seen from point E in (A) ■Hull ■Hull ■Propulsion propeller ■Motor for propeller drive ■Inlet side waterway ■Exit side Waterway ■Water surface ■Arrows indicating the ship's direction ■Patent applicant Mitsuo Okamoto

Claims (1)

[Claims] A ship shape that guides the water that rises on the water surface in front of a sailing ship to the rear of the ship through a channel installed in the hull, suppresses the turbulent flow of water that occurs on the rear side, and prevents wave-making resistance from occurring during navigation. ship of