Journal of the Korean Society of Marine Environment & Safety (해양환경안전학회지)

The Korean Society of Marine Environment and safety (해양환경안전학회)
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The Effect of Transient Eccentric Propeller Forces on Shaft Behavior Measured Using the Strain Gauge Method During Starboard Turning of a 4,700 DWT Ship

스트레인 게이지법을 이용한 4,700 DWT 선박의 우현 전타시 프로펠러 편심추력이 축 거동에 미치는 영향 연구

  • Lee, Jae-ung (Division of Marine Mechatronics, Mokpo National Maritime University) ;
  • Kim, Hong-Ryeol (Training Ship, Mokpo National Maritime University) ;
  • Rim, Geung-Su (Training Ship, Mokpo National Maritime University)
  • 이재웅 (목포해양대학교 해양메카트로닉스학부) ;
  • 김홍렬 (목포해양대학교 실습선) ;
  • 임긍수 (목포해양대학교 실습선)
  • Received : 2018.04.11
  • Accepted : 2018.06.27
  • Published : 2018.06.30
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Abstract

Generally, after stern tube bearing shows a significant increase in local load due to propeller load, which increases the potential adverse effects of bearing failure. To prevent this, research on regarding shaft alignment has been carried out with a focus on reducing the relative slope between the shaft and support bearing(s) under quasi-static conditions. However, for a more detailed evaluation of a shafting system, it is necessary to consider dynamic conditions. In this context, the results revealed that eccentric propeller force under transient conditions such as a rapid rudder turn at NCR, lead to fluid-induced instability and imbalanced vibration in the stern tube. In addition, compared with NCR condition, it has been confirmed that eccentric propeller forces given a rapid rudder starboard turn can lift a shaft from the stern tube bearing in the stern tube, contributes to load relief for the stern tube bearing.

선박 축계는 프로펠러 하중의 영향으로 선미관 후부베어링의 국부하중 증가가 현저히 나타나 축계 선미관 베어링 손상의 위험이 증대된다. 이를 방지하기 위해 수행된 추진축계 정렬연구는 주로 준정적 상태(quasi-static condition)에서 축과 지지베어링간의 상대적 경사각을 감소시키는데 중점을 두어 진행되어 왔다. 그러나 보다 상세한 평가를 위해서는 동적상태를 추가로 고려하는 것이 필요하다. 4,700 DWT 선박을 대상으로 NCR로 운전중 급속으로 우현 전타할 때 추진축계가 받는 영향에 대해 연구하였다. 연구결과 선미 유동장 변화에 의해 프로펠러 편심추력이 과도 상태가 되어 프로펠러에 불평형 진동이 유발되는 것을 확인하였다. 우현 전타시의 프로펠러 편심추력은 NCR 조건대비 축을 선미관 베어링으로부터 들어 올리는 힘으로 작용하여 선미관 베어링 하중완화에 기여하고 있음을 확인하였다.

Keywords

References

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