KR20080092850A - Ship - Google Patents

Abstract

A ship is provided to improve fuel consumption by increasing propulsion performance of a propeller formed on a rear part thereof. A ship includes a hull(1), a propeller(2), stern pins(3), and bilge pins(4). The propeller is installed on a stern of the hull. The stern pins are installed on both sides of the hull in rear of the propeller and are sloped in opposite direction to a direction of revolution of the propeller. The bilge pins are formed on both sides of the hull around a bilge part and are sloped upward facing the stern. The profile of a front portion of the stern pins is upwardly and smoothly sloped toward the direction of the stern.

Description

Ship {SHIP}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a ship provided with a fin that improves the propeller efficiency while improving the return flow distribution on the rotating surface of the propeller to obtain the return flow gain.

In general, the cross-sectional area of the hull peaks near the midship and gradually decreases closer to the stern and bow. In low speed vessels such as tankers and bulk carriers, the hull cross-sectional shape is approximately the same as the cross-sectional shape of the midship part in the range of about 30% of the length between perpendiculars. Is selected. In addition, the part of a hull whose hull cross-sectional shape is the same as the cross-sectional shape of a hull center part is called a parallel body.

Also, the repaired liver is the horizontal distance between the after perpendicular (abbreviated as "A.P.") and the foreline (abbreviated as "F.P."). Where AP is the vertical line passing through the intersection of the load line and the center line of the rudder stock, and FP is the vertical line passing through the intersection of the load line and the front of the stem. to be.

In addition, a square station (abbreviated as "SS") is a dimensionless coordinate which makes A.P. 0 and F.P. This SS is used for indicating the position of the hull in the front-rear direction in the field of linearity. In the case of the non-linear type described above, the hull parallel portion is approximately between SS 3.5 and SS 6.5.

The cross-sectional shape of the midship part, ie the midship section, is approximately square, and the contour of the part between the ship side and the bottom of the ship forms an arc. This arc is called a bilge and its radius is called a bilge radius. In addition, the height of the upper end of the bilge, that is, the boundary between the arc and the vertical surface on the ship side is called the bilge height. In the case of a merchant ship, the bilge radius in a ship's center cross section is about 10% of the ship's depth at most.

In parallel to the hull, the bilge radius and bilge height are constant. However, as the distance from the hull parallel part increases, the bilge radius gradually increases, and the horizontal part of the ship bottom or the vertical part of the ship side disappears, and thus the entire cross-sectional shape of the hull is formed into a curve. In addition, in the vicinity of the stern, the lower part of the hull is cut to form an overhang in order to install a propeller and a key.

When such ships go straight at constant speed, the seawater around the hull parallels flows parallel along the ship side and the ship bottom. However, in the rear of the hull parallel part, since the water flow which flows parallel to the ship side in the hull parallel part faces the overhang part, a downflow occurs. In addition, upward flow occurs because the water flows flowing in parallel to the bottom of the ship toward the overhang portion. The downward flow and the upward flow cross each other and form a vortex (bilge vortex) to be separated from the hull. Therefore, a problem arises in that the pressure behind the hull decreases and the resistance of the hull increases.

In addition, the bilge vortex peeled from the hull surface may flow to the rear of the hull through the rotation surface of the propeller, and may not flow into the rotation surface of the propeller. For this reason, a wake gain cannot be obtained and the propulsion efficiency of a propeller falls also arises.

Here, one of the inventors of the present application, in Patent Document 1, is provided with a pin (hereinafter referred to as "bilge pin") on the bilge behind the hull parallel part, and guides the bilge vortex peeled off the hull surface to the rotating surface of the propeller. It is proposed to improve the backflow distribution in the rotating surface of the propeller. Hereinafter, this bilge pin will be described briefly.

6-8 is an external view of the hull rear part of the ship disclosed by patent document 1, FIG. 6 is a perspective view, FIG. 7 is a side view, and FIG. 8 is a top view.

6 to 8, the hull 11 is provided with a key 12, a propeller 13, and a bilge pin 14. The hull parallel part of the hull 11 terminates at the rear end cross section 15 of the hull parallel part, and the hull 11 gradually narrows toward the stern end. In addition, in the case of the hull 11, the end surface 15 of the parallel part of the hull parallel part is located approximately SS 3.4. In addition, 16 has shown the ship side parallel parallel part boundary line, ie, the boundary line of a ship side and a bilge (refer FIG. 7).

Since the bilge pin 14 needs to be disposed behind the generation point of the bilge vortex, the starting point (front end) 17 of the bilge pin 14 is from SS 1.5 behind the hull parallel part end face 15. Selected within the range of SS 2.5. In addition, since the bilge pin 14 needs to be disposed above the bilge vortex, the height of the starting point 17 of the bilge pin 14 is made lower than the upper end of the bilge in the hull parallel part. In addition, the end point (rear end) 18 of the bilge pin 14 is higher than the starting point 17 so that the pin 14 has an upward inclination of 3 ° to 30 ° from the bow toward the stern in the side view ( See FIG. 7).

Moreover, it is preferable that the effective length 19 of the said bilge pin 14 shall be below the bilge radius in a hull parallel part. Moreover, it is preferable that the width | variety 20 of the said bilge pin 14 shall be 20%-50% of the bilge radius in a hull parallel part (refer FIG. 8).

FIG. 9 is a view of the hull 11 viewed from the stern direction, in which the cross section (ie, the hull transverse cross section at the starting point 17 and the end point 18 at the starting point 17 and the end point 18) cut in the cross-section shown by the AA and BB lines in FIG. Pin 14 is shown. As can be seen from FIG. 9, the bilge pin 14 is mounted such that its rectifying surface (surface receiving water flow) is perpendicular to the hull shell.

10 is an explanatory diagram for explaining the action of the bilge pin 14. When the bilge pin 14 is not provided, the bilge vortex is separated from the hull near the rear end of the hull parallel portion, as indicated by the flow line 21, and the region 22 above the propeller 13 is closed. Flows toward. Therefore, the upper end of the bilge vortex does not flow into the rotation surface of the propeller (13). On the other hand, when the bilge pin 14 is provided, the flow of the bilge vortex toward the region 22 is deflected downward, so that the entire bilge vortex flows into the rotating surface of the propeller 13 as indicated by the flow line 23.

11 and 12 are countercurrent distribution diagrams on the rotating surface of the propeller 13. FIG. 11 shows a case where the bilge pin 14 is not provided, and FIG. 12 shows a case where the bilge pin 14 is provided. 11 and 12, the numerical values attached to the contour lines are dimensionless numbers called wake coefficients. When the vessel velocity is V and the velocity of the water flow flowing into the rotating surface of the propeller 13 is Va, the return coefficient is expressed as (V-Va) / V. If the return coefficient is large, the relative velocity of the water flow flowing from the propeller 13 into the rotating surface of the propeller 13 becomes small, so that the propulsion efficiency of the propeller 13 is increased.

11 and 12, it can be seen that the bilge vortex 14 peeled from the hull guides the bilge vortex peeled from the hull to the rotating surface of the propeller 13 to increase the return on the rotating surface of the propeller 13.

Patent Document 1: Japanese Utility Model Registration No. 3097653

As described above, according to the invention described in Patent Document 1, the propulsion efficiency of the propeller 13 can be increased by increasing the return in the rotating surface of the propeller 13.

However, the bilge vortex guided to the rotating surface of the propeller 13 by the bilge pin 14 is biased toward the upper semicircle of the rotating surface of the propeller 13, and the effect of the bilge pin 14 is not applied to the lower semicircle. Therefore, the return coefficient of the lower semicircle is smaller than that of the upper semicircle (see FIG. 12). That is, the improvement of the propulsion efficiency of the propeller 13 by invention of patent document 1 had the problem which is not enough.

SUMMARY OF THE INVENTION The present invention has been made to solve this problem, by inducing water flow along the lower hull surface immediately before the propeller to the lower semicircle under the rotating surface of the propeller to improve the distribution of the return in the lower semicircle, and to reverse the direction of rotation of the propeller. It aims at improving fuel consumption by generating a swirl flow in the direction to improve the propeller efficiency.

The first configuration of the ship of the present invention is a ship in which bilge pins are provided on both strings of the outer plate of the bilge portion behind the rear end of the hull parallel portion, and stern end pins are provided on both strings of the outer plate near the propeller bossing at the stern end. The profile of the bilge pin is inclined upward toward the stern direction, and the profile of the rear end of the stern end pin is inclined in a direction opposite to the rotation direction when the propeller is advanced.

Here, as a profile, the shape of the pin shown by the side view (orbital projection which saw a pin from the starboard or port side of a hull) is mentioned.

Incidentally, the inclination in the direction opposite to the rotational direction of the propeller forward means that the ship equipped with the right-side propeller (the propeller generating the forward propulsion force when rotating in the clockwise direction from the stern direction), It means that the end is inclined upward toward the stern direction, while the rear end side of the port pin is inclined downward toward the stern direction. Moreover, in the ship provided with the propeller of the left rotation, it means that it is inclined downward toward the stern direction to the rear end of a starboard pin, and inclines upward toward the stern direction to the rear end of a port pin.

According to this configuration, by providing both the stern end pin and the bilge pin on the hull, the semicircle distribution of the lower half of the propeller's rotating surface is improved by the stern end pin, and the semicircle distribution of the upper half of the propeller's rotating surface is improved by the bilge pin. Therefore, the wake flow distribution is improved in all regions of the rotating surface of the propeller, and as a result, the fuel consumption rate of the ship is improved.

Further, since the inclination in the direction opposite to the rotational direction of the propeller is given to the rear end of the stern end pin, swirl flow in the direction opposite to the rotational direction of the propeller occurs. As a result, the elevation of the blades of the propeller with respect to the water flow is increased, and the apparent pitch of the propeller is increased, so that the propeller efficiency is improved.

In addition to the first configuration, the second configuration of the ship of the present invention is characterized in that the profile of the front end portion of the stern end pin is gently inclined upward toward the stern direction.

According to this configuration, since the upward sloping slope is applied to the front end of the stern end pin toward the stern direction, the water flow of the hull surface flowing in the inclined upward direction toward the stern direction contacts the stern end pin at a small angle. Therefore, the direction of water flow can be changed efficiently, while suppressing the increase in resistance caused by the fins. Incidentally, the gentle inclination here means that the inclination is gentle compared to the rear end side of the pin.

In addition, when the profile of the front end and the rear end of the stern end pin is made into a gentle curve, since the water flow does not disturb at the boundary of the front end and the rear end, the direction of water flow can be changed more efficiently.

According to a third configuration of the ship of the present invention, in addition to the first or second configuration, the bilge pin and the stern end pin are single plate fins.

Here, as a single plate pin, the pin which consists only of the member cut out from a single board | plate material is referred to, and is a concept which opposes the build up pin which assembles a some member.

According to such a structure, since a pin can be manufactured only by cutting and bending, it can manufacture a pin cheaply.

As described above, according to the present invention, there is an effect capable of improving the propulsion performance of the ship and improving the fuel consumption rate.

Further objects, features and advantages of the present invention can be more clearly understood from the following detailed description and the accompanying drawings.

EMBODIMENT OF THE INVENTION Hereinafter, the preferable form for implementing this invention is demonstrated with reference to drawings.

1 is a side view of a ship according to an embodiment of the present invention, showing a rear portion of the hull 1 in the center of the hull (SS5). As shown in FIG. 1, the hull 1 includes a propeller 2 at the stern, a stern end pin 3 immediately before the propeller 2, and a bilge pin 4 at the bilge portion near SS 2.4. Each is provided. In addition, 5 represents a ship side parallel parallel part boundary line, 6 represents a hull parallel part rear end, and 7 represents the innermost part of an overhang part, respectively. The propeller 2 is a right-turning propeller that generates forward propulsion when rotating in the clockwise direction as viewed from the stern. Therefore, when the hull 1 advances, the wing of the propeller 2 moves from the top to the bottom on the right side (viewed from the stern) of the rotational surface of the propeller 2, and moves from the bottom to the top on the left side.

The stern end pin 3 is a rectifying plate disposed on both sides of the stern portion just before the propeller 2. The rear end of the stern end pin 3s of the starboard is inclined upward toward the stern, and the rear end of the stern end pin 3p of the port not shown in the figure is inclined downward toward the stern. Accordingly, the stern end pin 3s on the starboard side induces the water flow toward the propeller 2 upward, and the stern end pin 3p on the port side induces the water flow toward the propeller 2 downward. . In this manner, the stern end pin 3 generates a swirl flow in a direction opposite to the rotational direction of the propeller 2.

In addition, together with the left and right strings, the front end portion of the stern end pin 3 is provided with a gentle descending gradient toward the bow direction. By providing this descending gradient, the elevation angle with respect to the water flow a which flows from the boat bottom toward the overhang part of a stern can be made small. Thereby, the generation of turbulence on the surface of the stern end pin 3 can be suppressed, and the water flow a can be efficiently guide | induced to the semicircle below the rotating surface of the propeller 2.

The bilge pin 4 is a rectifying plate symmetrically disposed on the left and right strings of the hull 1. In addition, since the action and effect of the said bilge pin 4 were already demonstrated, description is abbreviate | omitted here.

FIG. 2 is a view of the hull 1 viewed from the stern direction, showing a cross-sectional shape cut in the cross-section shown by the AA line, the BB line and the CC line of FIG. will be. As can be seen from FIG. 2, the stern end pin 3 and the bilge pin 4 are mounted so that their rectifying surfaces are perpendicular to the hull shell plate. In addition, 8 represents the outer diameter of the boss of the propeller 2, P represents the direction of rotation of the propeller 2, Fs represents the direction of the water flow guided by the stern end pin 3s of the starboard, And Fp represents the direction of water flow induced by the stern end pin 3p of the port.

3 is a side view of the stern end pin 3s of the starboard. 4 is a side view of the stern end pin 3p of a port.

The stern end pin 3 is a rectifying plate which guides the water flow a (see FIG. 1) flowing from the ship bottom portion in front of the propeller 2 toward the overhang portion to the lower half circle of the rotating surface of the propeller 2. Therefore, it is preferable to approach the innermost part 7 (refer FIG. 1) as far as possible below the center of the said propeller 2 as much as possible. Here, the position of the stern end pin 3 is selected so that the last end of the stern end pin 3 may be near the lower end of the boss of the propeller 2.

The length and width of the stern end pin 3 are appropriately selected based on the diameter Dp of the propeller 2. If the stern end pin 3 is made larger than necessary, the stern end pin 3 itself becomes a cause of resistance and reduces the fuel consumption reduction effect. Accordingly, an optimal value of the length and width of the stern end pin 3 is required by experiment or calculation. Also, the optimum value of the length of the stern tip pin 3 is in the range of approximately 0.5Dp to 1.0Dp.

In addition, the front end of the stern end pin 3 is provided with a downward gradient of about 3 ° to 5 ° in the bow direction to reduce the elevation angle of the water flow flowing into the stern end pin 3. .

The rear end of the stern end pin 3s of the starboard is given an ascending gradient of 15 ° to 25 ° toward the stern direction (see Fig. 3), and the rear end of the stern end pin 3p of the starboard toward the stern direction. Give a down gradient of 15 ° to 25 ° (see FIG. 4). In addition, the angle of the rear end of the stern end pin 3 is determined by experiment.

Further, although the gradient of the stern end pin 3 is different at the front end and the rear end, this gradient can be changed continuously. This is because if there is an articulation at the front and rear edges, the flow is disturbed at that part. In the present embodiment, a profile is formed in a straight line at the front end and the rear end of the stern end pin 3, and at the same time, the front end and the rear end are connected by an arc contacting the straight line.

In addition, the stern end pin 3 is produced by cutting the rolled steel sheet and bending to form the profile shown in FIGS. 3 and 4.

5 is a side view of the bilge pin 4. As shown in Fig. 5, the front end of the bilge pin 4 is at the position of SS2.4. Moreover, the height of the front end of the bilge pin 4 measured from the baseline is about 1.3 m, and is lower than the bilge height 1.5 m in a hull parallel part. In addition, the profile of the bilge pin 4 has an upward gradient toward the stern direction.

In addition, the bilge pin 4 is produced by cutting one rolled steel sheet in the same manner as the stern end pin 3.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, modifications, and changes within the scope not departing from the technical spirit of the present invention are possible in the art. It will be evident to those who have knowledge of.

1 is a side view of a ship showing an embodiment of the present invention.

2 is a view of the ship from the stern direction;

Figure 3 is a side view of the stern end pin on the starboard side according to the embodiment of the present invention.

4 is a side view of the stern end pin on the port side according to the embodiment of the present invention.

5 is a side view of a bilge pin according to the embodiment of the present invention.

6 is a perspective view of a hull rear portion of a ship showing an example of the prior art;

7 is a side view of a vessel of an example of the prior art;

8 is a plan view of a vessel of an example of the prior art;

9 is a view of the vessel of the prior art as seen from the stern direction;

10 is an explanatory diagram for explaining the action of the bilge pin.

Fig. 11 is a wake distribution diagram on a rotating surface of a propeller when no bilge pin is provided.

Fig. 12 is a wake distribution diagram on a rotating surface of a propeller when a bilge pin is provided.

* Brief description of drawing symbols *

1: hull 2: propeller

3: stern end pin 3p: stern end pin

3s: Starboard's Stern Tip Pin 4: Bilge Pin

5: Outer side parallel part boundary 6: Rear side of side parallel part

7: innermost part of overhang part 8: outer diameter of boss of propeller

9: stern tube 11: hull

12: key 13: propeller

14: bilge pin 15: end surface parallel to the hull

16: side shell parallel boundary 17: starting point

18: End point 19: Effective length

20: width 21, 23: flow line

22: area

Claims (3)

As a ship in which the bilge pins are installed on both strings of the outer plate of the bilge part behind the hull parallel part, and the stern tip pins are installed on both strings near the stern propeller bosing. The profile of the bilge pin is inclined upward toward the stern direction, Profile of the rear end of the stern end pin is inclined in a direction opposite to the direction of rotation when the propeller is advancing Ship. The method of claim 1, Profile of the front end portion of the stern end pin is characterized in that it is inclined gently upward toward the stern direction Ship. The method according to claim 1 or 2, The bilge pin and the stern end pin is characterized in that the end plate pin Ship.

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