• 한국해양공학회지
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• 제22권4호
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• pp.84-89
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• 2008

It is hard to find experimental data for a model test of small high-speed planning boats. It is difficult to verify the performance seen in a model test for a high-speed boat because the ship-model scale-ratio is very small and the flow velocity of the circulating water channel and the X-carriage speed of the towing tank are restricted. Therefore most hull-form designs for high-speed small boats depend on the sea-trial test result for similar boats or evaluation through numerical calculations. This study investigated the anti-rolling effect of the stern sub-body in a 50-knot doss planning boat. To carry out this work, new model test procedures were set up in the actual sea. Using this method, the anti-rolling effect of the stern sub-body was investigated. A stern sub-body attached to a planning boat was proved to be effective in reducing the roll and pitch angle.

• 대한조선학회논문집
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• 제34권4호
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• pp.21-30
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• 1997

본 논문은 복합지지형 초고속선에 사용될 pod형 물분사 추진장치에 대한 예인수조 실험 및 성능해석 결과를 보여준다. 선체와 물분사 흡입구간의 상호작용이 매우 작은 것으로 가정하고 선체저항 및 추진성능 실험을 토대로 시험선 운항시 성능을 해석하였다. 축류식 펌프를 갖는 pod형물분사 추진장치를 설계하고 단독특성시험 시스템을 개발하여 실험을 수행하였다. 실험결과로부터 펌프 성능, 제트효율, 흡입구 및 노즐의 손실계수 등 물분사 추진장치 설계 및 특성파악에 유용한 자료를 확보하였다. 실험결과는 설계요구조건과 비교적 좋은 일치를 보여준다.

• 대한조선학회논문집
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• 제44권4호
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• pp.389-397
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• 2007

This research describes a framework to compare and analyze the icebreaker(Terry Fox) resistance in pack ice condition between with a refrigerated ice and a synthetic ice. Model tests with a refrigerated ice have been conducted at Institute for Ocean Technology (IOT/NRC) and the tests with a synthetic ice were conducted at Pusan National University towing tank. For the validation of further tests of measurement and accuracy, the open water tests were first carried out with same model ship to compare the test results of both Institutes. Two different size of the wax-type synthetic ice were used and tests were conducted in pack ice of three different concentration ice conditions. The test results show that the difference of resistance between with synthetic and with refrigerated ice becomes larger according to the increase of ship speed. Although the quantity of resistance difference is not so small in high speed range, the present study is predicted to be used as a useful correlation between synthetic and refrigerated ice.

• International Journal of Naval Architecture and Ocean Engineering
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• 제3권3호
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• pp.174-180
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• 2011

This paper shows added mass and inertia can be acquired from the pure heaving motion and pure pitching motion respectively. A Vertical Planar Motion Mechanism (VPMM) test for the spheroid-type Unmanned Underwater Vehicle (UUV) was compared with a theoretical calculation and Computational Fluid Dynamics (CFD) analysis in this paper. The VPMM test has been carried out at a towing tank with specially manufactured equipment. The linear equations of motion on the vertical plane were considered for theoretical calculation, and CFD results were obtained by commercial CFD package. The VPMM test results show good agreement with theoretical calculations and the CFD results, so that the applicability of the VPMM equipment for an underwater vehicle can be verified with a sufficient accuracy.

• 해양환경안전학회지
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• 제18권6호
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• pp.597-603
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• 2012

해상에서의 안전한 예인 업무를 수행하기 위해서는 정확한 예인력의 추정이 필요하며, 이를 위해서는 예선의 저항성능 특성에 대하여 정확히 파악해 두어야 할 필요가 있다. 본 연구에서는 먼저 정수중 예선 주위의 유동 특성 및 예선의 저항추진 성능을 파악하고자 회류수조에서 예선 모형을 이용하여 실험을 실시하였다. 모형실험은 무한수심 조건에서의 1/33.75 축척으로 제작된 예선 모형을 이용하였으며, 설계속도를 7노트로 선정하고 역조와 순조의 조류 영향을 고려하여 5~10노트의 속도 구간에서 각 속도별로 실행하였다. 또한 파랑에 의한 예선의 운동응답 함수와 부가저항을 추정하기 위하여 수치계산을 실행하였으며, 이에 대한 결과를 정수중에서의 실험을 통하여 얻게 된 데이터와 비교하였다. 이와 같은 해석 결과 파랑중 부가저항은 선수파 및 속도가 높아질수록 증가하며, 유효마력은 정수중에 비하여 70 % 정도 증가하고 있는 현상을 확인할 수 있었다.

• 대한조선학회지
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• 제4권1호
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• pp.49-54
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• 1967

The authors considered the effects of trim in the small coastal passenger boat upon resistance in this paper. Any change of trim no matter how small, necessarily produces some effect upon resistance. The relations between the resistance coefficients and trim were investigated through the towing test of the Model $MCI-P_1-65$, Korean Standardized Ship, GT 70 tons passenger boat in the gravitational tank. The Lines of the Model are given in Fig. 1. Principal dimensions and other characteristics vary with the trim in general. Those values varied with the trim for $MCI-P_1-65$ are tabulated in table 1. The resistance was measured at five conditions such as even keel, 0.0273L, (original designed trim) 0.0473L, 0.0663L, 0.0873L trim by the stern, fixing the displacement corresponding to the designed load water line. Model was made of wood in length of 3.5 feet coated with varnish, and without appendages. As the artificial turbulent stimulator, the sand strip method was used. The results of model towing tests, correcting to water temperature of $70^{\circ}F$, were expanded to full scale using the Schoenherr's friction formula and surface roughness allowance coefficient of 0.0004. The authors point out, the following results. 1) Optimum trim which gives the minimum resistance exists for every speed at constant displacement and each comes to the same value. For $MCI-P_1-65$ optimum trim is 0.0673L trim by the stern(Fig.4-The cross curves of the resistancecoefficients). 2) At constant displacement, when LCB(longitudinal position of center of buoyancy) varies with the trim, there exists optimum value of LCB which gives minimum resistance for every speed and each comes to the same value. For $MCI-P_1-65$ optimum position of LCB is 8%L aft from midship section (Fig.6).

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2007년도 추계학술발표회
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• pp.91-95
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• 2007

본 연구는 해양에 유입되는 부유폐기물을 효과적으로 수거할 수 있는 시스템을 개발하고자, 우기철에 폐기물의 성상을 조사한 전보의 예비조사와 기초실험 결과를 바탕으로 각 장치의 구조와 규격을 확정하고 해상에서 그 성능 검증을 수행하였다. 그 결과 본 시스템의 구집기구는 전개장치의 전개력에 의해 선박 진행시 1회에 수평방향으로 15m이상의 해역을 소해하는 것으로 나타나 현행 폐기물 수거선박보다는 수거 효율이 매우 높았으며, 폐기물이 최종적으로 유입되는 Net의 수면상 높이는 예인속도 5kt이내에서 50cm이상을 유지하여 폐기물의 유입성능이 우수함을 알 수 있었다. 또한 부유 폐기물 수거실험에서는 매 실험 당 평균 약 200kg 정도의 폐기물이 그물망을 가득 채워 본 연구에서 고안한 수거시스템의 성능은 매우 양호한 것을 확인할 수 있었다.

• Journal of Advanced Marine Engineering and Technology
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• 제41권4호
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• pp.316-322
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• 2017

본 논문의 주 목적은 수치해석 도구를 활용하여 저항성능 관점에서 우수한 선형을 개발하는 것이다. 최종 개발된 선형의 성능 평가를 위해 수조 모형시험을 수행하였다. 현존선은 도면을 바탕으로 실물과 도면의 타당성 검토를 위해 실태조사를 수행하였다. 실태조사 시에 실제 운항 상태인 주 운항 배수량 및 주 운항 선속을 확인하였다. 수치해석을 바탕으로 현존선의 저항성능을 검토하였다. 개발선은 선수어깨의 파형개선, 배수량 분포의 균형화, 단면형상의 수정 그리고 중앙 스케그의 크기와 형상 변경에 관한 스터디를 통해 도출되었다. 수치해석 결과 개발선은 조파저항 개선에 의해 저항성능 관점에서 주 운항 선속인 11노트에서 약 15% 개선된 양을 보여주었다(Table 4 참조). 개발된 선형의 성능 평가를 위해서 수조 모형시험을 수행하였으며 그 결과 11노트에서 약 17% 개선된 양을 보여주었다(Table 5 참조).

• 수산해양기술연구
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• 제41권3호
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• pp.179-187
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• 2005

This study was conducted in order to the experiment of bottom trawl fisheries in the sea mount of central northern pacific($30^{\circ}-40^{\circ}N$, $170^{\circ}-175^{\circ}E$), during the period of July 1 to August 25, 2004 by commercial trawl ship. Fishing experiment was carried out by bottom trawl, with the codend of 110mm mesh size. The number of 101 test fishing was done in the sea mount of central northern pacific during 56 days and the total catches were 198,593kg as 18 fish species, and CPUE/day and catches/day were 8.3 hours towing time and 3,546kg. Catch ratio according to each fishing ground was higher with the order of B, C, and E, and catches for B was 7,171.0kg during the towing time of 13.2 hours. Main target species were Pseudopentaceros richardsoni and Beryx splendens, there was 14.9% of damage ratio for fishing gears on catching the target fishes inhabiting on the rough sea bottom. Catches by water depth was the order of 300m below, 301-350m, 451-500m and 351-400m. It is thought that there was no problem on the mesh size because most of fishes caught from the experimental fishing was 30cm over.

• 대한조선학회논문집
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• 제51권2호
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• pp.171-177
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• 2014

A two-dimensional particle image velocimetry (2D PIV) system in a towing tank is employed to measure a wake field of a very large crude oil carrier model with rotating propeller in self propulsion condition, to identify characteristics of wake of a propeller working behind a ship. Phase-averaged and time-averaged flow fields are measured for a horizontal plane. Scale ratio of the model ship is 1/100 and Froude number is 0.142. By phase-averaging technique, trajectories of tip vortex and hub vortex are identified and characteristic secondary vortex distribution is observed in the hub vortex region. Propeller wake on the starboard side is more accelerated than that on the port side, due to the difference of inflow of propeller blades. The hub vortex trajectory tends to face the port side. With the fluctuation part of the phase-averaged velocity field, turbulent kinetic energy (TKE) is also derived. In the center of tip vortex and hub vortex region, high TKE concentration is observed. In addition, a time-averaged vector field is also measured and compared with phase-averaged vector field.