• International Journal of Naval Architecture and Ocean Engineering
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• 제4권4호
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• pp.488-503
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• 2012

The stern boat deployment system was investigated to evaluate the capability of launching and recovering rigid hull inflatable boat (RHIB) via the stern ramp. The main parameters to launch and recover RHIB were tested at the design stage. The combined hydrodynamic effect of the stern wake and the water jet flow made it difficult to maintain the maneuvering and sea-keeping ability of RHIB approaching to the stern ramp. The safe recovery course was proposed to maintain the directional control of RHIB and to reduce the combined hydrodynamic effect in the transom zone. To evaluate the feasibility of RHIB recovery, the stern sill depth was measured in various conditions and the ramp availability time was obtained. Also, the experimental percent time operability (PTO) test was performed by the number of successive launching and recovering operations.

• 한국해양공학회지
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• 제29권6호
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• pp.405-410
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• 2015

This paper reports the hull form development and resistance performance of a 5-ton-class catamaran-type coastal fishing boat. The weight estimation and preliminary design were basically extracted from existing coastal fishing vessels. In addition, the resistance performance was investigated using a model test in a high-speed circulating water channel and was analyzed in comparison to an existing catamaran fishing vessel. As a result, the modified hull achieved an approximately 30% reduction in resistance compared to the previous hull. The stability or boarding sensitivity of the modified hull form was more stable or comfortable than the original hull form based on a trim and sinkage comparison between the two boats.

• 대한조선학회논문집
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• 제45권2호
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• pp.124-131
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• 2008

This paper presents the analysis of resistance performance and bow waves for the resistance-minimized hull form of small fishing boat by using numerical simulations and model tests. The resistance-minimized hull form is developed from an original hull form which is selected from existing small fisher boats in our country. In order to estimate the resistance performance for the original and the developed hull form, several numerical simulations and model tests are carried out. Marker and Cell(MAC) method and Marker-Density method are adopted to simulate the free-surface bow waves around advancing hull surface. The results of numerical simulations are compared with the model tests in towing tank. The results show that the resistance performance of the resistance-minimized hull form is improved than that of the original hull form. The results of this study will be a good guide to the hull form development of small fishing boats in future.

• 한국해양공학회지
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• 제27권6호
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• pp.1-6
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• 2013

A 25ft class fishing leisure boat is developed, and the resistance performances are investigated by a model test in a high-speed circulating water channel. The design speed of the developed ship is 25 knots using a 150 ps outboard engine. A catamanan type hull form using a planing section is adopted considering the Froude number and large deck area. The effect of a center body attached on the bottom of the cross deck is studied under various conditions. Wave patterns are observed to make clear the relationship between the resistance performance and the wave characteristics. The results show that the shape of the center body and the position of the chine line can have a strong effect on the resistance performance in a certain velocity range.

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권2호
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• pp.201-211
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• 2018

This paper illustrates recent advancements relative to a non-conventional propulsion system for boats and is based on two previous papers of the author presented at a conference (see Muscia, 2015a,b). The system does not consider propellers and utilizes the vibration generated by two or more pairs of counter rotating masses. The resultant of the centrifugal forces applies an alternate thrust to the hull that oscillates forward and backward along the longitudinal axis of the boat. The different hydrodynamic drag forces that oppose to the oscillation produce a prevalently forward motion of the vessel. The vibration that causes the motion can be suitably defined to maximize the forward displacement and the efficiency propulsion of the system. This result is obtained by using elliptical gears to rotate the counter rotating masses. The computation of the propulsion efficiency is based on a suitable physical mathematical model. Correlations between numerical experiments on models and possible full scale application are discussed. Some remarks in relation to practical applications and critical issues of the propulsive solution are illustrated. The results have been obtained with reference to a CAD model of a real boat already manufactured whose length is approximately equal to 13 m.

• 한국기후변화학회지
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• 제5권4호
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• pp.301-311
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• 2014

In this study, we estimated the amount of fuel used fishing boats of individual based on the results of survey of the activity data such as operations and activities specification of fishing boats in Korea. Based on the classification system of the domestic fishing boat, and to estimate average fuel consumption and the greenhouse gas emissions, showed emission factors per fishing boat. This was suggested to be able to apply the registration data area in the future, and estimates the emissions of greenhouse gases. Based on these results, it tries to provide the basic data that can be used when you want to create a local government measures to reduce scenario in the future.

• Ocean Systems Engineering
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• 제11권4호
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• pp.373-392
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• 2021

The present paper purposes a numerical evaluation of the Thai Long-Tail Boat propeller (TLTBP) performance by without and with propeller boss cap fins (PBCF) in full-scale operating straight shaft condition in the first. Next, those are applied to inclined shaft conditions. The actual TLTBP has defined an inclined shaft propeller including the high rotational speed, therefore vortex from the propeller boss and boss cap (hub vortex) have been generated very much. The PBCF designs are considered to weaken of vortex behind the propeller boss which makes the saving energy for the propulsion systems. The blade sections of PBCF developed from the original TLTBP blade shape. The integrative for the TLTBP and the PBCF is analyzed to increase the performance using computational fluid dynamics (CFD). The computational results of propeller performance are thoroughly compared between without and with PBCF. Moreover, the effects of each PBCF component are computed to influence the TLTBP performance. The fluid flows around the propeller blades, propeller boss, boss cap, and vortex have been investigated in terms of pressure distribution and wake-fields to verify the increasing efficiency of propulsion systems.

• 헤리티지:역사와 과학
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• 제39권
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• pp.5-38
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• 2006

우리나라 고분에서 목관이 출토된 예는 창원 다호리유적과 무녕왕릉, 창녕 송현동고분군 7호분뿐이지만, 일본의 고분시대에는 목관의 외형과 구조 등을 추정 복원할 수 있는 자료가 비교적 풍부한 편이다. 일본 고분시대의 목관은 제작방법에 따라 통나무 내부를 파내어 만든 고발식(刳拔式)과 판재를 결합한 조합식(組合式)으로 분류되며, 형태적으로는 주형, 할죽형(割竹形), 상형(箱形) 등으로 나눌 수 있다. 그리고 상형목관은 관재의 결합방식에 의해 조립식(組立式)과 정부식(釘付式)으로 구분된다. 목관의 수종은 금송재가 전 시기에 걸쳐 차별적인 선택이 이루어졌지만, 고분시대 후기에는 삼나무나 편백나무 등 일상에서 쉽게 구할 수 있는 목재가 사용되기도 한다. 우리나라의 창원 다호리유적와 창녕 송현동고분군 7호분 출토 목관은 제작방법 및 형태에 있어 일본의 고발식목관과 유사하며, 무녕왕릉의 왕 왕비의 관은 일본의 정부식목관 출현에 직접적인 영향을 미친 것으로 인식되고 있다. 창녕 송현동고분군 7호분 목관은 통나무배를 전용한 것으로 일본에서 제기되고 있는 주장(舟葬)과 같이 황천국(黃泉國)으로 가기 위한 수단으로 배를 목관으로 시용하였다는 사후 세계관을 반영한 것이 아니라 녹나무가 가진 방충, 부식억제 효과를 최대한 이용한 실용적인 이유로 판단된다. 창녕지역은 녹나무의 식생지역이 아닌 내륙에 위치하고 있기 때문에 관재로서 녹나무를 확보하기 어려웠을 것이고, 이러한 이유로 부득이하게 기존에 사용하였던 배를 전용할 수밖에 없었던 것이다. 7호분 축조 딩시 시대적 상황을 볼 때, 녹나무는 당시 가야와 활발한 대외교섭이 있었던 왜에서 수입한 것으로 추정된다.

• 월간경쟁저널
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• 84호
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• pp.32-37
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• 2002

• 수산해양기술연구
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• 제6권1호
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• pp.23-36
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• 1970