A Numerical Study on the Effects of Maneuverability of Ship with Low Forward Speed by Increasing Rudder Force

Abstract

2Recent accidents of crude oil tankers have resulted in sinking, grounding of vessels and significant levels of marine pollution.Therefore, International Maritime Organization (IMO) has been strengthening the regulations of ship maneuvering performance in MSC 137. The evaluation of maneuvering performance can be made at the early design stage; it can be investigated numerically or experimentally. The main objective of this paper was to investigate the maneuvering performance of a VLCC due to the increase of rudder force at an early design stage for low speed in shallow water conditions. It was simulated in various operating condition such as deep sea, shallow water, design speed and low speed by using the numerical maneuvering simulation model, developed using MMG maneuvering motion equation and KVLCC 2 (SIMMAN 2008 workshop). The effect of increasing the rudder force can be evaluated by using numerical simulation of turning test and ZIG-ZAG test. The research showed that, increasing the rudder force of a VLCC was more effective on improving the turning ability than improving the course changing ability especially. The improvement of turning ability by the rudder force increasing is most effective when the ship is sailing in shallow water at low forward speed.

Maneuverability Performance of a KRISO Container Ship (KCS) with a Bulb-Type Wavy Twisted Rudder and Asymmetric Pre-Swirl Stator

“…Maneuverability is essential for the development of such ships, particularly because reliability is the most important factor. Special rudders, such as flaps and schilling rudders [3][4][5], are being developed and applied to improve ship maneuverability. Special rudders are known to provide excellent maneuverability by delaying stall and generating high lift, but in actual operating conditions, efficiency loss due to additional drag and maintenance difficulties due to complex structures are serious problems.…”

Performance Improvement in a Wavy Twisted Rudder by Alignment of the Wave Peak

“…Gim et al [4] studied the distribution of velocity and energy behind a flap rudder based on variations in the flap angle. Kim et al [5] studied the maneuvering performance and turning ability using a numerical method in shallow and deep-sea conditions based on the increase in the performance of the rudder. Bertram [6] proposed that flapped rudders could provide a considerably greater lift curve slope and a 60-70% greater maximum lift compared to a conventional rudder in the same area.…”