• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.53-56
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• 2005

Hybrid rocket had many advantage with compared to solid and liquid rockets. In this study, swirl flow hybrid motor was designed and manufactured. And the methods of regression rate improvement wire considered. Thrust was calculated with pressure of the combustion chamber and the regression rate was measured in low flow rate of oxidizer. Several problems and solutions of operating hybrid rocket was presented.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.311-317
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• 2005

Hybrid rocket had many advantage with compared to solid and liquid rockets. In this study, swirl flow hybrid motor was designed and manufactured. And the methods of regression rate improvement were considered. Thrust was calculated with pressure of the combustion chamber and the regression rate was measured in low flow rate of oxidizer. Several problems and solutions of operating hybrid rocket was presented.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.11
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• pp.103-109
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• 2012

Samsung Thales has developed a small-sized autonomous underwater vehicle "BOTO" verified by a mathematical model simulation. The hydrodynamic coefficients and drag force were experimented at circulating water channel for validating cruising performance of the AUV. Based on the mathematical model, we simulated turning radius and way-point tracking on horizontal plane using way-point tracking algorithm. In this paper we introduce the vehicle system and the sea trial test results will be shown.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.11a
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• pp.12-13
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• 2018

For navigation safety, navigators have to be familiar with maneuverabilities. When a vessel encounters a danger of collisions and stranding, maneuverability is essential for the safety of ship. It is composed of turning, course change, speed change, etc. In the latter part, maneuverabilities and motion of Training Ship HANBADA are provided by full-scale measurement in the $10^{\circ}/10^{\circ}$ Zig-Zag Test, $20^{\circ}/20^{\circ}$ Zig-Zag Test and Turning Circle Test(Port and Starboard). It aims to provide information on maneuverabilities and motion of Training Ship HANBADA so that the navigators can take proper action to avoid.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.209-215
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• 1979

The manoeuvrabilities of a ship are decided by the values of her manoeuvring indices. The manoeuvring indices consist of two kinds: indices K and T. The former decides a ship's turning ability and the latter, the length of time delay to a steady turning motion after her rudder has finished the turn of an ordered angle. In this paper, the author figured out the values of the manoeuvring indices of the m. s. 'SAEBADA' (GT: 2,275,7 ton), the training ship of tile National Fisheries University of Busan through her Z test and analyzed these values and the other data which were obtained from her Z test to study her manoeuvrabilities. The results of]tamed are summarized as follows: 1. The manoeuvring indices K' of the m. s. 'SAEBADA' were $1.052(at\;10{\circ}\;Z\;test)\;0.925(at\;20{\circ}\;Z\;test)\;and\;0.877(at\;30{\circ}\;Z\;test)$. Her manoeuvring indices $0.815(at\;10{\circ}\;Z\;test)\;0.502(at\;20{\circ}\;Z\;test)\;and\;0.441(at\;30{\circ}\;Z\;test)$. Her above calculated values K', T' showed that her obeying ability to the turn of her rudder was more increased when her rudder was used to large angle than to small angle, but on the other hand in this case her turning ability was slightly reduced. 2. As it appeared that the calculated K'-values of the m.s. 'SAEBADA' were slightly smaller than the standard K'-values of the fishing boats similar in length, and her overshoot angles at her Z test were greater than other general ships, her turning ability was found to t]e slightly lower. 3. When the m. s. 'SAEBADA' took a turn at her $10^{\circ}\;Z$ test, running distance was about 8.6 times her own length and didn't exceed the standard manoeuvrability distance, 5 to 11 times general ships' own length, therefore she was considered to have a good manoeuvrability synthetically.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.8
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• pp.111-121
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• 2005

A 100kW class gas turbine combustor was developed and tested for PPU(Primary Power Unit) of ground vehicle. The combustor which employed annular-reverse type and pressure swirl atomizer was designed through 1-D analysis, 3-D thermal flow analysis and combustor performance was experimentally investigated on the combustor test rig. The test result was satisfactory. The developed combustor was also tested for environmental and endurance specification under engine adopted conditions and the application of a state-of-the-art gas turbine combustor to ground vehicle PPU turned out to be successful.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.1
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• pp.84-92
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• 1995

The methods by turning circle test and maneuvering indices have been used to study and evaluate the maneuverability of a ship. However recently many studies utilizing the GPS are made on the measurement of the turning circle and in the fishery and hydrographic survey. In this paper, the author carried out the turning circle test using the differential GPS and dumb card together, and compared the data measured by them and analyzed the accuracies of them to obtain the utility basic ones on the measurement of the turning circle by the DGPS. The main results area s follows : 1) To check the accuracies of the GPS, the circling experiments of 50m radius by the DGPS were made on the ground. The accuracies of turning circle measured by the DGPS were found to be very high as the errors of 1.5m. 2) the turning circle by the DGPS could be measured very accurately, by the seed, rudder angle, starboard and port respectively. 3) The turning circle measured by the dumb card was found to be measured accurately as much as the DGPS, when using large rudder angle, the turning circle was large, the turning circle by the dumb car could not be measured accurately on account of large error of bearing of compass. 4) The tactical diameters by the DGPS in case of the rudder angle 35。~5。, were found to be 2.6。15.0 times the Lpp of S.T HAELIM-3 at her slow speed 2.8~16.6 times her Lpp at her half speed, 3.1~17.4 times her Lpp at her full speed. The tactical diameter by the dumb card was found to be 2.4~9.5 times, 2.6~9.6 times, 3.2~12.2 times her Lpp respectively, in the above case and speed.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.5
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• pp.465-472
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• 2011

Recently, ultra large scale of ship is being ordered continuously and because of that, the accurate prediction of ship maneuverability in design stage becomes important matter. The model test like PMM test or CFD analysis are representative methods for predicting the maneuverability of ship. In this study, the captive model tests were carried out for predicting maneuverability of MOERI container ship(KCS) which is opened to the public using X-Y Carriage of Ocean Engineering Wide Tank of University of Ulsan. Considering the dimensions of tank, 2m class model ship was used for captive model test. CMT(Circular Motion Test) was performed for obtaining purer hydrodynamic coefficients related to yawing velocity. For getting hydrodynamic coefficients which cannot be obtained using CMT, PMM test(Planar Motion Mechanism test) were also performed. The maneuverability prediction results by simulation are compared with those of other research institutes.

• Journal of the Society of Naval Architects of Korea
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• v.57 no.1
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• pp.52-59
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• 2020

This study aims to investigate the bow thruster performance of the research vessel "NARA" by full-scale maneuvering trials. The thruster test method refers to ITTC's recommended procedures and guidelines. Turning tests with the bow thruster are performed at speed conditions of 0, 2, and 4 knots. The test results indicate that the Rate of Turn (ROT) increased when the ship is in a higher speed condition. Due to the position of the propeller and the housing of the bow thruster, there is difference in the efficiency of the bow thruster according to the turning direction. Zigzag tests with the bow thruster were conducted at speed conditions of 2 and 4 knots. At speeds above 4 knots, it seems difficult to change the course only with the bow thruster.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.75-77
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• 2016

IMO는 해상에서의 선박 안전 향상을 위해 선박의 복원성능과 조종성능에 관한 국제적 기준을 제시하고 있다. 이러한 기준은 선박 연구자가 수행하는 연구의 방향에도 영향을 미치고 있다. 기존의 수행된 연구는 복원성능과 조종성능의 각각의 분야에서 독립적으로 수행되어 왔으며, 아직 두 분야의 상호 관계에 관한 연구는 미비한 실정이다. 이에 본 논문에서는 선박의 복원성능과 조종성능의 상호 관계를 정량적으로 규명하고자 기초적인 실험 연구를 수행하였다. 이를 위해 복원성능을 나타내는 지표인 GM과 선박의 조종성능을 나타내는 지표인 선회성능을 통해 두 항복 간 상호 관계의 정량적 분석을 시도하였다. 자유항주 모형선을 이용한 선회 시험을 실시하였고, 그 결과 GM 감소에 따른 선회반경 감소 및 초기 횡경사 각도 증가를 확인했으며, 그 변화의 경향은 서로 다르게 나타나는 것을 확인하였다.