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Vessels with small ducts and methods of judging the application of small ducts to ships

A duct and ship technology, applied in the field of ships with small ducts, can solve the problems of large ships not being used and large interference, and achieve the effects of small frictional resistance, improved efficiency and low vibration

Active Publication Date: 2017-08-29
PORT & AIRPORT RES INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The interference between the large duct and the propeller is large, so the efficiency is improved in the actual sea area where the load is increased, but the cavitation generated between the propeller and the duct becomes a problem, and it is hardly used in large ships

Method used

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  • Vessels with small ducts and methods of judging the application of small ducts to ships
  • Vessels with small ducts and methods of judging the application of small ducts to ships
  • Vessels with small ducts and methods of judging the application of small ducts to ships

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 2

[0124] Example 2 has an increased thrust compared to Example 1, and Example 3 has an increased thrust compared to Example 2.

[0125] Such as Figure 8 As shown, the smaller the distance L between the leading edge of the propeller 10 and the rear end 22 of the duct 20, the more the thrust increases.

[0126] Figure 9 is a graph showing the relationship between the propeller load condition (Ct) and the eddy current resistance (%) in the actual sea area with respect to the hull, Figure 10 It is a diagram showing the relationship of the main items of each type of ship.

[0127] Here, the propeller load condition (Ct) means the same as the propeller load degree, and is a numerical value obtained by dividing the thrust generated by the propeller by "the dynamic pressure of the water flow x the area of ​​the propeller circular surface". In addition, the eddy current resistance is viscous resistance which is the hull resistance, and is viscous resistance caused by eddy currents ...

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Abstract

The invention provides a ship with a small duct, which is characterized in that: it comprises a propeller (10) installed at the stern of the hull (1) and a duct (20) installed in front of the propeller (10), so that the hull (1) forms For the propeller load condition in the actual sea area is more than 1.0 and the eddy current resistance is more than 10%, and the duct (20) is a small duct whose diameter is more than 20% and less than 50% of the diameter of the propeller (10). Therefore, according to the eddy current resistance and the propeller The relationship between the load conditions specifies the hull (1) that can obtain the horsepower reduction effect, and as an energy-saving device that has both the characteristics of a large duct and a medium duct, the shape of the propeller (10) is designed, and the position close to the front of the propeller (10) Arranging a small duct (20) not only suppresses cavitation in the actual sea area where the load degree increases, but also makes use of the interference with the small duct (20) to control the radial direction load distribution of the propeller (10) for efficiency optimize.

Description

technical field [0001] The present invention relates to a ship with a small duct including a propeller installed at the stern of the hull and a duct installed in front of the propeller. Background technique [0002] Among the existing ducts installed near the propeller, there are large ducts that cover the propeller and have a larger diameter than the propeller, and medium-sized ducts that are slightly smaller in diameter than the propeller and are arranged in front of the propeller. [0003] The large duct that covers the propeller type is called a ducted propeller and is used as an effective thruster when the load degree integrated with the propeller is high. The reason for this is that the propeller and the duct have a large interference, and it is reasonable to use performance that takes this interference into account as a propeller. [0004] On the other hand, the medium-sized duct in front of the propeller, which is slightly smaller in diameter than the propeller, is ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B63H5/16B63B1/32B63H5/07
CPCB63H1/18B63H5/16B63B1/08Y02T70/10
Inventor 佐佐木纪幸川岛英干藤泽纯一久米健一一之瀬康雄
Owner PORT & AIRPORT RES INST