JPH0452152Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a sea chest structure for taking in seawater provided at the bottom of a ship.

BACKGROUND OF THE INVENTION A typical ship is provided with a seawater intake chamber, or a sea chest, for cooling the main engine and other auxiliary equipment. Recently, some ships have been designed to emit air bubbles from the bow of the ship in order to block the noise generated by the ship itself. By the way, if a sea est is simply installed on the bottom of a ship like this, air bubbles will get into the sea est, so in order to prevent this, the sea thest structure shown in Figures 5 and 6 was adopted. . This sea chest structure is
The first sea crest 22 formed on the bottom 21 of the ship
A rectifying plate (air water) 25 having a streamline shape in plan view is protrudingly provided on the hull outer plate 24 corresponding to the water intake 23, and a large number of rectifying plates 25 are provided at positions corresponding to the first water intake 23 of the rectifying plate 25. A second intake port 26 having a slit 26a is formed and the second intake port 26 has a slit 26a.
The intake port 26 and the first water intake port 23 are communicated with each other through a cylindrical body 27 . Incidentally, 28 is a water suction pipe connected to the sea chest 22.

Problems to be Solved by the Invention According to the above configuration, as shown in FIG. A is generated, and this vortex b collides with the inner rear wall surface 27a of the cylindrical body 27, causing a water pressure fluctuation due to vortex excitation within the seat est 22, which causes a resonance phenomenon with the structural system. . FIG. 8 shows the state of pressure fluctuation within the seat est. from now,
It can be clearly seen that the pressure fluctuations inside the sea chest are extremely large, and the fluctuations (vibrations) become larger in proportion to the increase in ship speed (flow speed). In addition, in FIG. 7, b indicates the velocity distribution of the ocean current.

Therefore, an object of the present invention is to provide a seat top structure that can solve the above problems.

Means for Solving the Problem In order to solve the above problem, the sea trest structure of the present invention has a rectifier plate protrudingly arranged on the hull outer plate corresponding to the first water intake of the sea trest formed at the bottom of the ship, and the rectifier is A second water intake is formed at a position rearward of the first water intake of the plate, and both of these water intakes are communicated through a cylindrical body, and the inner rear wall surface of the cylindrical body is inclined rearward. be.

Effect In the above configuration, the ocean current flowing along the front surface of the current plate separates at the front end of the second water intake, generates a vortex, and then flows backward and collides with the rear wall inside the cylindrical body. Since this rear wall surface is inclined rearward, the vortex flows smoothly onto the rear surface of the current plate, and almost no pressure fluctuation occurs within the cylindrical body, that is, the seat est.

Embodiment Hereinafter, an embodiment of the present invention will be described based on FIGS. 1 to 4. In FIGS. 1 and 2, reference numeral 1 designates a sea chest installed at a proper location on the bottom 2 of the ship, and a first water intake port 4 is formed in the hull outer plate 3, and a water intake pipe 5 is connected thereto. Reference numeral 6 denotes a rectifying plate (air water) which is arranged parallel to and protruding from the hull outer plate 3 at a position corresponding to the first water intake 4, and has a streamlined shape in plan view, that is, it is widened at the front and extends toward the rear. It is shaped like an oval with a narrowed edge. A second water intake 7 having a large number of slits 7a is formed at a position rearward of the first water intake 4 of the baffle plate 6, and the first and second water intakes 4, 7 communicate with each other through a cylindrical body 8. At the rear of the cylindrical body 8, a wall plate 9 that slopes backward is attached. Note that the baffle plate 6 is fixed to the hull outer plate 3 by a cylindrical body 8 and a mounting member 10. Reference numeral 11 indicates a plurality of seawater guide plates disposed within the cylindrical body 8;
Reference numeral 2 indicates an inspection opening formed at the front of the rectifying plate 6, that is, at a position corresponding to the first water intake port 4, and 13 indicates a lid thereof.

According to the above configuration, as shown in FIG. 3, the ocean current flowing along the front surface of the current plate 6 is
A vortex A is generated as it separates at the front end of the water intake 7, and then flows backward and collides with the wall plate 9 in the cylindrical body 8. However, since this wall plate 9 is tilted backward, the vortex rectifies smoothly. It flows on the rear surface of the plate 6 and causes almost no vibrations in the cylinder 8 due to pressure fluctuations.
In addition, since the fluid flows smoothly, the number of vortices generated is small and reduced. In addition, in FIG. 3, B indicates the velocity distribution of the ocean current. Figure 4 shows the state of pressure fluctuations, and it is clear that even if the ocean current becomes faster, there is almost no vibration due to pressure fluctuations. In addition, seawater is taken into the sea chest 1 through the second water intake 7, the cylindrical body 8, and the first water intake 4, as shown by arrow C in FIG.

Effects of the invention According to the above-mentioned configuration of the present invention, the second water intake formed in the current plate is shifted rearward with respect to the first water intake, and the rear wall surface inside the cylindrical body is tilted rearward. Since the vortex generated at the front edge of the second water intake flows smoothly outward on the rear wall surface, almost no vibrations due to pressure fluctuations occur inside the cylindrical body, that is, inside the sea chest.

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment of the present invention, where Figure 1 is a cross-sectional view, Figure 2 is a view taken in the direction of the − arrow in Figure 1, and Figure 3 is a cross-sectional view showing the flow state of ocean currents. Figures 4 and 4 are graphs showing pressure fluctuations, Figures 5 to 8 show conventional examples, Figure 5 is a sectional view, Figure 6 is a view taken along the - arrow in Figure 5, and Figure 7 is a graph showing pressure fluctuations. is a cross-sectional view showing the flow state of the ocean current, and FIG. 8 is a graph showing pressure fluctuations. 1...Sea chest, 2...Bottom, 3...Hull outer plate, 4...1st water intake, 6...Brighter plate, 7...
...Second water intake, 8...Cylindrical body, 9...Wall plate.

Claims (1)

[Scope of utility model registration request] A rectifier plate is protrudingly arranged on the hull outer plate corresponding to the first water intake of the Sea Chest formed at the bottom of the ship, and a second water intake is formed at a position rearward of the first water intake of the rectifier plate, and both of these A sea chest structure characterized in that a water intake port is communicated through a cylindrical body, and the inner rear wall surface of the cylindrical body is inclined rearward.