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Evaluation of the maneuverability of a real ship with flap rudder

Flap rudder를 이용한 조종성능 평가

  • AHN, Jang-Young (College of Ocean Sciences, Jeju National University) ;
  • KIM, Kwang-il (College of Ocean Sciences, Jeju National University) ;
  • KIM, Min-Son (Marine Production System Major, Kunsan National University) ;
  • LEE, Chang-Heon (College of Ocean Sciences, Jeju National University)
  • 안장영 (제주대학교 해양과학대학) ;
  • 김광일 (제주대학교 해양과학대학) ;
  • 김민선 (군산대학교 해양생산시스템전공) ;
  • 이창헌 (제주대학교 해양과학대학)
  • Received : 2020.03.10
  • Accepted : 2020.05.04
  • Published : 2020.05.31

Abstract

In order to offer specific information needed to assist in operation of a ship with same type rudder through evaluating the maneuverability of training ship A-Ra with flapped rudder, sea trials based full scale for turning test, zig-zag test with rudder angle 10° and 20°, and spiral test at service condition were carried out on starboard and port sides around Jeju Island according to the standards of maneuverability of IMO. As a result, the angular velocity of port turn was higher than that of starboard turn. Therefore, the size of turning circle was longer on the starboard side. In addition, variation of the transfer due to various factors was more stable than those of the others. In the Z-test results, the mean of 1st and 2nd overshoot angles were 9.8°, 6.3° and 15.3°, 9.2° respectively when the port and starboard was 10°; the 1st overshoot angle were 18°, 13.7° when using 20°. Her maneuverability index T' and K' can be easily determined by using a computer with the data obtained from Z-test where K' and T' are dimensionless constants representing turning ability and responsiveness to the helm, respectively. In the Z-test under flap rudder angle 10°, the obtained K' value covered the range of 2.37-2.87 and T' was 1.74-3.45. Under the flap rudder angle 20°, K' and T' value showed 1.43-1.63, 1.0-1.73, respectively. In the spiral test, the loop width was unstable at +0.3° and -0.5°-0.9° around the midship of flap rudder. As a result, course stability was comparatively good. From the sea trial results, training ship ARA met the present criterion in the standards of maneuverability of IMO.

Keywords

References

  1. An YS, Lee HG, Park BS and Jang CS. 2015. Maneuverability of a DWT 8,000-ton oil/chemical tanker by real sea trials - A comparison between the semi-balanced rudder and the flap rudder - J Kor Soc Fish Technol 51, 257-264. https://doi.org/10.3796/KSFT.2015.51.2.257.
  2. Kim YG, Kim SY, Ha BI, Kim HS and Lim CS. 2006. Prediction of maneuverability of a ship with flap rudder. Journal of the Society of Naval Architects of Korea 43, 171-176. http://dx.doi.org/10.3744/SNAK.2006.43.2.171.
  3. Kopp PJ. 1993. Mathematical model for a real time ship maneuvering, station-keeping, and sea-keeping training simulator. Carderock division naval surface warfare center (CRDKNSWC-HD-1427-01), 24.
  4. Lee CH, Ahn JY, Kim SJ, Kim MS and Choi CM. 2017. A study on maneuverability evaluation by the research vessel JERA. J Kor Soc Fish Tech 53, 177-186. https://doi.org/10.3796/KSFT.2017.53.2.177.
  5. Lee HG, An YS, Park BS and Jang CS. 2015. A study on the turning ability of a DWT 8,000-ton oil/chemical tanker by real sea trials - A comparison between the semi -balanced rudder and the flap rudder- J Kor Soc Fish Technol 51, 245-256. https://doi.org/10.3796/KSFT.2015.51.2.245
  6. Lee HY, Park HS and Shin SS. 2000. Maneuvering performances of a ship with flapped rudder, J Kor Soc Marine Environ & Safety 4, 97-101.
  7. Lee SK and Lee SJ. 1998. Evaluation of course-keeping quality of a ship by Zig-zag test. Journal of the Society of Naval Architects of Korea 35, 54-60.
  8. Matsumoto N and Suemitsu K. 1980. The prediction of maneuvering performances by captive model tests. J Kansai Soc Naval Archit Japan 176, 11-22.
  9. Yasukawa H and Yoshimura Y. 2015. Introduction of MMG standard method for ship maneuvering predictions. J Mar Sci Technol 20, 37-52. https://doi.org/10.1007/s00773-014-0293-y.