• 수산해양기술연구
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• 제51권2호
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• pp.257-264
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• 2015

This study is intended to provide navigator with specific information necessary to assist the avoidance of collision and the operation of ships to evaluate the maneuverability of dead weight tonnage 8,000 tons Oil/Chemical tanker. The actual maneuvering characteristics of ship can be adequately judged from the results of typical ship trials. Author carried out sea trials based full scale for turning test, Z" maneuvering test, man overboard rescue maneuver test, inertia stopping test. Consequently, $2^{st}$ Overshoot yaw angle of the semi balanced rudder and flap rudder in ${\pm}20^{\circ}$ zig-zag test showed $22.2^{\circ}$ and $18.0^{\circ}$, respectively. The maneuverability of the vessel was good in the flap rudder. The man overboard rescue maneuver maneuverability test was most favorable in the flap rudder and the full load condition. The results from tests could be compared directly with the standards of maneuverability of IMO and consequently the maneuvering qualities of the ship is full satisfied with its.

• International Journal of Naval Architecture and Ocean Engineering
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• 제4권3호
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• pp.322-334
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• 2012

This paper shows the numerical and experimental results about the hydrodynamic characteristics of X-Twisted rudders having continuous twist of the leading edge along the span. All the results were compared with those of the semi-balanced rudder. Calculation through the Reynolds-Averaged Navier-Stokes Equation (RANSE) code with propeller sliding meshes shows large inflow angle and fast inflow velocity in the vicinity of ${\pm}0.7$ R from the shaft center, so it may cause cavitation. Also, X-Twisted rudder has relatively small inflow angles along the rudder span compared with semi-balanced rudder. For the performance validation, rudders for two large container carriers were designed and tested. Cavitation tests at the medium sized cavitation tunnel with respect to the rudder types and twisted angles showed the effectiveness of twist on cavitation and the tendency according to the twist. And the resistance, self-propulsion and manoeuvring tests were also carried out at the towing tank. As a result, in the case of X-Twisted rudder, ship speed was improved with good manoeuvring performance. Especially, it was found out that manoeuvring performance between port and starboard was well balanced compared with semi-balanced rudders.

• 수산해양기술연구
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• 제51권2호
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• pp.245-256
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• 2015

This study is intended to provide navigator with specific information necessary to assist the avoidance of collision and the operation of ships to evaluate the maneuverability of dead weight tonnage 8,000 tons Oil/Chemical tanker. The actual maneuvering characteristics of ship can be adequately judged from the results of typical ship trials. Author carried out sea trials based full scale for turning test in ballast condition and full load condition, semi balanced rudder and flap rudder. The turning circle maneuvering were performed on the starboard and port sides with $35^{\circ}$ rudder angle at the normal continuous rating. The results from tests could be compared directly with the standards of maneuverability of IMO and consequently the maneuvering qualities of the ship is full satisfied with its.

• 대한조선학회지
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• 제27권4호
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• pp.27-31
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• 1990

양력면(揚力面)의 양력계산(揚力計算)에 흔히 쓰이고 있는 방법(方法)을 크게 나누면 Vortex Lattice 법(法)과 Mode Function법(法)이 있다. 잘 알려진 것 처럼, Vortex Lattice법(法)은 해(解)의 수렴성(收斂性)은 좋으나 계산시간(計算時間)이 많이 걸리는 문제점(問題點)이 있고, Mode Function법(法)은 계산시간(計算時間)은 짧으나 해(解)가 특이(特異)해 지는 경우가 있다. 그러므로 본(本) 논문(論文)에서는 양방법(兩方法)의 장점(長點)들을 살리도록, 양력면(揚力面)을 Span 방향(方向)으로 분할(分割)하고 각(各) Strip Mode Function을 사용하여 Vortex를 분포(分布)시켜, 양력면이론(揚力面理論)으로 양력(揚力)을 계산(計算)하였다. 우선 Horn Type의 반균형타(半均衡舵)에 본(本) 계산법(計算法)을 적용(適用)하여 타직압력(舵直壓力)을 계산(計算)하고 타(舵) 단독시험(單獨試驗)을 병행(竝行)하여 계산법(計算法)의 유용성(有用性)을 검증(檢證)하였다. 그 결과(結果), Stall과 같은 비선형적(非線形的) 유체현상(流體現象)이 일어나지 않는 한(限), 본(本) 계산법(計算法)은 유용(有用)하다는 결론(結論)을 얻었다. 끝으로, 본(本) 계산법(計算法)을 평행(平行)하게 늘어선 한척(隻)의 장방형타(長方形舵)에 적용(適用)하여 두 타(舵) 사이의 상호간섭(相互干涉)도 계산(計算)하였다.