• 대한조선학회논문집
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• 제59권3호
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• pp.149-156
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• 2022

In order to study the open-water test and analysis techniques for pumpjet propulsors in the Large Cavitation Tunnel (LCT), at the Korea Research Institute of Ships and Ocean Engineering, a set of test equipment was designed and manufactured. The pumpjet propulsor is composed of rotor, stator and duct resulting in the strong interaction between the components. A ring-shaped sensor was developed to measure the thrust and torque for duct and stator. The test equipment including the pumpjet is installed on an existing POW dynamometer in the reverse direction. The results from the reverse POW test setup were validated against those from the conventional POW test setup in the Towing Tank (TT) as well as in the LCT. The pumpjet open-water test was conducted at the Reynolds number of around 1.0×106, at which the obtained experimental data became stable in the Reynolds number effect test. The open-water test for the rotor (rotor-only) was conducted to study whether the duct and stator should be considered as a part of the hull or the propulsor. On the basis of the test results, it was shown that the duct and stator could be included in the propulsor. The total thrust, combined thrust of rotor, duct, and stator was used for the pumpjet open-water test analysis. As the whole pumpjet is defined as a propulsor, it is thought that the self-propulsion test and analysis could be conducted in the same way as that of the conventional propeller.

• 대한조선학회논문집
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• 제59권5호
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• pp.271-279
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• 2022

In order to study the self-propulsion test and analysis techniques for the submerged body with pumpjet propulsors in the Large Cavitation Tunnel (LCT), at the Korea Research Institute of Ships and Ocean Engineering, a set of test equipment was designed and manufactured. The pumpjet propulsor is composed of rotor, stator and duct which results in the strong interaction between the components. To measure the thrust and torque for duct and stator, a ring-shaped sensor was applied. The test equipment including pumpjet is installed on the stern of the submerged body. As the whole pumpjet including duct and stator was considered as the propulsor from pumpjet open-water test, the self-propulsion test was conducted in the same way. The total thrust, combined thrust of rotor, duct and stator was used for the pumpjet self-propulsion test analysis. Accordingly, the self-propulsion test and analysis were conducted in the same way as those of the conventional propeller. The full-scale performances of the pumpjet propulsor were compared with those of the reference propeller. On the basis of the present study, it is thought that the pumpjet propulsor would be designed optimally.

• 한국자기학회지
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• 제25권6호
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• pp.189-197
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• 2015

최근 차량의 연비규제 강화로 인해, 기존 내연기관의 차량 부품 구동방식이 유압방식 대신 전동방식으로 대체되어 가고 있다. 이러한 부품의 대표적인 예가, Electronic Power Steering(EPS)이며, 현재 대부분의 차량에 적용되고 있다. EPS의 핵심 부품으로서는 전동기가 있으며, EPS의 조향감 개선 및 진동/소음 저감을 위해 전동기의 Cogging torque 및 Torque Ripple 저감이 요구된다. 일반적으로 Cogging torque 및 Torque ripple을 저감하기 위해서, 고정자 또는 회전자에 스큐를 적용한다. 본 연구에서는 고정자에 스큐가 적용된 Bushless PMSM(Permanent Magnet Synchronous Motor)의 설계 방법 및 해석방법에 대해 소개한다. 고정자 skew가 적용된 EPS용 PMSM에 대해 초기 설계를 진행하고, RSM(Response Surface Methodology)을 이용한 최적설계를 수행한다. 유한요소해석을 통해 역기전력, Inductance, Load torque 등의 성능을 확인한다. 마지막으로 시제품 제작 및 실험을 통해 설계 방법에 대한 신뢰성을 검증한다.