JPS625115B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ship (including a marine structure) whose hull resistance can be reduced by reducing wave collapse.

2. Description of the Related Art Waves such as those shown in FIGS. 1 and 2 are commonly generated in conventional ships, especially large ships and ships traveling at relatively high speeds.

At that time, the front shoulder wave collapse 3 is located near the front shoulder 1 of the hull.
However, a stern wave collapse 4 occurs near the stern 2, and a bow wave collapse 5 occurs near the bow.

In addition, wave collapse at the rear shoulder may occur near the rear shoulder of the hull.

Among these wave collapses, the bow wave collapse 5 can be reduced to some extent by adopting a spherical bow 6, etc., but there is no easy way to reduce other wave collapses, which causes energy loss. There is a problem in that it increases the hull resistance.

The present invention aims to solve these problems, and is a phenomenon in which wave breakage causes shear flow in the fluid in the thin surface water along the water surface, causing separation of the flow along the water surface. Focusing on this, the present invention aims to provide a ship equipped with a device that accelerates the above-mentioned thin surface water to reduce the occurrence of wave collapse.

For this reason, a ship equipped with the wave collapse mitigation device of the present invention can be installed on the ship's side near the water surface in at least one of the ship body parts where wave collapse is likely to occur, such as near the front and rear shoulders of the hull and near the stern. The nozzle is characterized in that a nozzle that sucks the flowing surface water in the direction of accelerating it is provided so that its suction port extends above and below the water surface in the vicinity of the surface water.

Embodiments of the present invention will be described below with reference to the drawings. Figures 3 to 5 show a ship equipped with a wave collapse mitigation device as an embodiment of the present invention.
The figure is a plan view, FIG. 4 is a side view, and FIG. 5 is a detailed view of the nozzle.

As shown in these figures, this ship is provided with water suction nozzles 7 near the front shoulder 1 and stern 2 of the ship, each having a suction port extending above and below the water surface 10 near the surface water. It is being

Each nozzle 7 is connected to a pump (not shown) inside the ship, and is installed along the ship's side shell 11 so as not to disturb the flow along the ship's side, as shown in FIG.

The suction flow B from each nozzle 7 accelerates the surface water in the flow A along the ship's side toward the downstream.

By accelerating the flow of surface water and giving momentum to the flow in this way, the occurrence of wave collapse as a separation phenomenon of the flow along the water surface 10 is reduced, thereby reducing water head loss. It is.

In addition, since the suction port of the nozzle 7 is formed so as to extend above and below the water surface 10 near the surface water,
Even if the draft changes during this action, the occurrence of wave collapse can continue to be reduced.

FIG. 6 is a graph showing the experimental results of the hull resistance of a ship equipped with the wave collapse mitigation device according to the present invention in comparison with a conventional case, and shows the results of experiments on the hull resistance of a ship equipped with the water suction nozzle 7 according to the present invention. The hull resistance has been significantly reduced.

Even when the nozzle 7 is provided only on the front shoulder portion 1 of the hull or only on the stern portion 2, a considerable reduction in hull resistance can be achieved.

In addition, in a boat type where wave breakage is likely to occur in the rear shoulder of the hull, the nozzle 7 is also installed near the water surface near the rear shoulder.

As detailed above, according to the ship equipped with the wave collapse mitigation device of the present invention, focusing on the fact that wave collapse is a separation phenomenon of the flow along the water surface, A nozzle that sucks the surface water flowing along the ship side in a direction that accelerates the surface water flowing along the ship side is placed on at least one of the ship's sides near the water surface among the parts of the ship body where wave collapse is likely to occur. It has an extremely simple structure that extends above and below the waves, effectively reducing wave collapse.
This has the advantage of reducing hull resistance.

[Brief explanation of the drawing]

Figures 1 and 2 show the shape of waves around a conventional ship, Figure 1 is its top view, Figure 2 is its side view, and Figures 3 to 5 are one embodiment of the present invention. This indicates a ship equipped with a wave collapse mitigation device.
Figure 3 is its plan view, Figure 4 is its side view, and Figure 5 is its top view.
The figure is a detailed view of the nozzle, and FIG. 6 is a graph showing the resistance characteristics of the ship according to the present invention in comparison with the conventional case. 1...Forward shoulder of the hull, 2...Stern, 7...Nozzle, 1
0...Water surface, 11...Ship side shell, A...Flow along the ship's side, B...Suction flow.

Claims (1)

[Claims] 1. A nozzle is installed on the ship's side near the water surface in at least one of the parts of the ship where wave collapse is likely to occur, such as near the front and rear shoulders and near the stern, which sucks in the direction of accelerating the surface water flowing along the ship's side. A ship equipped with a wave break mitigation device, characterized in that the suction port is provided near the surface water so as to extend above and below the water surface.