• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.89-89
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• 2017

해양경찰 소형 경비정에 주로 장착되었던 물분사(water jet type) propeller가 중대형 경비함으로 점차 확대되고 있으며, 축 형식은 2~4축, 유동을 제어하는 bucket 유형도 DRB, CSU(SRB) 방식으로 나뉘어져 있다. 그러나, W/Jet 추진기 고유의 운동 특성이 반영된 조함법의 연구가 부족한 편이다. 여기서는 함정에 장착된 W/Jet 유형별 SHS를 통하여 직접 구현해 보고, SHS 구현이 현실적으로 어려운 함정은 해양경찰 함정장들의 면담을 통하여 습득한 것을 이론적으로 구현 제시하여, 함정 조함시 지식적인 인적오류를 최소화하여 W/jet 추진기가 장착된 함정 승조원의 조함 능력 향상 및 안전운항에 기여하고자 한다.

• Proceedings of the KWS Conference
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• v.43
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• pp.213-215
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• 2004

Water jet propulsion system has high efficiency on middle to high speed, and it provides better safety than conventional screw propeller because it has not projected propeller and rudder. So many leisure boat and high-speed ferries use this propulsion system. We developed water-jet propulsion unit for small planning boat, and launched that in the boat, after that we tested water-jet unit in the lake. As a result, we certify heat dissipation at the bearing housing and reverse duct's shape for neutral position are important at the design, and alignment water-jet unit and keel line are important at the launching, and ship's resistance performance and jet's propulsion performance also are needed to consideration.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.3 s.234
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• pp.477-483
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• 2005

A propeller has been considered as one of the most critical elements in propelling ships. However, only a little research on the marine propeller has been carried out. Furthermore, fractures of the propeller have been frequently caused by fatigue, but only tensile strength, yield strength and elongation are discussed in Register of Shipping. For the above reasons, we have evaluated strength properties of A1BC3 and HBsC1, both which have been used for the marine propeller by using air jet chisel and then, presented a method of improving the strength.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.10
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• pp.48-53
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• 2019

A water jet propeller is a key component that generates propulsion during the start of a naval vessel. When failure or breakage occurs, the vessel cannot operate. Recently, a flow analysis and structural analysis were conducted to understand the cause of damage to a bolt on a water jet. In particular, the stress and strain acting on the fastening bolt (impeller shaft and tail shaft) were examined to determine the extent of misalignment between the impeller shaft and the tail shaft of the water jet propeller. The study determined that stress and strain were concentrated on the impeller shaft and the tail shaft bolt. The alignment of the propeller impeller shaft and the tail shaft increased significantly in response to the tail shaft bolt. Failure of the tail shaft bolt fastening can lead to misalignment between the impeller shaft and the tail shaft.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.341-346
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• 2010

In this paper, viscous flow calculation of pump-jet that is used as underwater propulsor was made by using RANS equation. For the validation, calculation for DTRC4119 marine propeller was made and reasonable agreements were obtained between the present results and the experiment. An unstructured overset mesh technique is used for analysis of relative motion between rotor and stator in pump-jet propulsor. Results for pump-jet propulsor were compared with computational results of another researcher.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2003.05a
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• pp.16-20
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• 2003

Recently, The fast change of fishing boat fishery surrounding environment is connected by request of fan shape development that meet in restructuring of existing fishing boat fishery and new community, economical surrounding. In southern sea district along the coast work and district along the coast fishing bats that sail to exposed propeller fishing net, rope etc.. cold real condition that accident is increasing every year. This study is thing which analyze main performance of minuteness water jet type district along the coast fishing boat through model examination to propeller protection tunnel sticking district along the coast fishing boat that correct existing stem shape for marine accident prevention of district along the coast fishing boat in viewpoint such as ideal and examines.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.2
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• pp.149-154
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• 2004

Results of a numerical simulation of a flowing of the underwater vehicles hull with the pump-jet nozzle are presented. It was calculate velocity distributions coefficients of the lift force the longitudinal moment of the hull with the pump-jet nozzle and isolated hull for some values of angle of attack. It was shown that the area of the influence of the nozzle on the velocities distribution of the hull and character of changing of coefficients of the lift force and the longitudinal moment and their derivatives depending on angle of attack.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.5
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• pp.89-94
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• 2008

Marine propeller is one of the most important element of ship, it must be taken care of design and maintenance of it. It is inevitable that corrosion pits have occurred on the marine propeller. If corrosion pits have occurred on the blades, they have been repaired ordinary by simple welding methods in shipyards. It must be that the strength is degraded in this process. In this paper, we represent the improvement method of fatigue strength degraded after repairing pits.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.1
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• pp.150-155
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• 2012

Water jet propulsion system has low efficiency than screw propeller at low speed, but has been applied in high speed ship due to its better cavitation performance and high rotation capacity. In this study, a numerical analysis was conduct to understand the flow in the propulsion system of 200HP grade water jet for small ship. As the result, it could be confirmed that total pressure and force of the flow was increased through the impeller and the straight-ability of discharging flow to outlet was improved by guide vane. Also, the reliability of numerical analysis was secured by comparing peripheral velocity calculated by design values with that calculated by numerical analysis.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.11a
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• pp.139-145
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• 2002

The flow zone through propeller jets are used in evaluating the environmental and constructional effects of navigation on the waterway. It relies on the characteristics of ships and water depth. A numerical model using the momentum theory of the propeller and Shield's diagram was developed in a restricted waterway. Equations for discharge are presented based on thrust coefficients and propeller speed and are the most accurate means of defining discharge. Approximate methods for discharge are developed based on applied ship's power. Equations for discharge are as a function of applied power, propeller diameter, and ship speed. Water depth of the waterway and draft of the shop are also necessary for the calculation of the grain size of the initial motion. The velocity distribution of discharge from the propeller was simulated by the Gaussian normal distribution function. The shear velocity and shear stress were from the Sternberg's formula. Case studies to show the influence of significant factors on sediment movement induced by the ship's propeller at the channel bottom are presented.