• Journal of Advanced Marine Engineering and Technology
• /
• v.40 no.4
• /
• pp.301-306
• /
• 2016

During the initial stage of propulsion shaft design, the shaft alignment process includes a thorough consideration of lateral vibration to verify the operational safety of the shaft. However, a theoretical method for analyzing forced lateral vibrations has not been clearly established. The methods currently used in classification societies and international standards can only ensure a sufficient margin to avoid the blade-passing frequency resonance speed outside the range of ${\pm}20%$ of the maximum continuous rating (MCR) for the engine. Typically, in shaft alignment analyses, longer center distances between the support bearings promote affirmative results, but the blade order resonance speed can approach the lower limit for lateral vibration. Therefore, this matter requires careful attention by engineers, and a verification of the theoretical analysis by experimental measurements is highly desirable. In this study, both theoretical and experimental analyses were conducted using strain gauges under two draught conditions of vessels used as 50,000-DWT oil/chemical tankers, introduced recently as eco-friendly ships. Based on the analyses, the influence of the lateral vibration on the shafting system and the system's reliability was reviewed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.04a
• /
• pp.454-455
• /
• 2014

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2010.05a
• /
• pp.574-575
• /
• 2010

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2012.10a
• /
• pp.378-379
• /
• 2012

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2013.10a
• /
• pp.879-881
• /
• 2013

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2005.11a
• /
• pp.3-4
• /
• 2005

With an increase in the size and power rate of ship, the stern tube bearing has become subject to severer operation conditions. Particularly it is expected to be exposed to extremely so severe lubrication conditions during low rotational operation that there is strong demand for clarifying the oil film characteristics of the stern tube bearing at the design stage with accuracy. So in this study, we conducted an analysis of the stern tube bearing characteristics taking arbitrary three-dimensional deflection of the shaft into consideration.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2012.06a
• /
• pp.183-183
• /
• 2012

As as result of development of new voyage route, especially Baltic seas, it is necessary for the design to meet ice class requirements as vessels continue to increase in this route. For this reason Finish-Swedish ice class has recently amended a regulation on the propulsion shafting design and engine output required for the ships which will be navigable in the brash ice channels broken by ice-breakers in Baltic seas. Therefore, this study shows the appropriate calculation methods for the design of engine output and propulsion shafting system based on ice class requirements.

• Journal of Power System Engineering
• /
• v.7 no.3
• /
• pp.29-34
• /
• 2003

Genetic algorithm is a optimization technique based on the mechanics of natural selection and natural genetics. Global optimum solution can be obtained efficiently by operations of reproduction, crossover and mutation in genetic algorithm. The authors developed a computer program which can optimize marine propulsion shafting by using binary-coded genetic algorithm and modal analysis method. In order to confirm the effectiveness of the developed computer program, we apply the program to a optimum design problem which is to obtain optimum diameters of intermediate shaft and propeller shaft in marine propulsion shafting. Objective function is to minimize total mass of shafts and constraints are that torsional vibration stresses of shafts in marine propulsion shafting can not exceed the permissible torsional vibration stresses of the ship classification society. The computational results by the program were compared with those of conventional design technique.

• Proceedings of KOSOMES biannual meeting
• /
• 2018.06a
• /
• pp.129-129
• /
• 2018

• Proceedings of KOSOMES biannual meeting
• /
• 2006.05a
• /
• pp.213-216
• /
• 2006

In this paper a development of shaft power measuring system for a small vessel is discussed. It is important that the exact power measurement of marine engine which is used for ship's propulsion since the engine power is related to ship's usage and its shaft design. Two gearwheel and magnetic sensors are adopted to measure torsional angle on the shaft. High resolution encoder is also applied to compensate the output signal from gearwheel. The calculation of shaft power is executed using measured signal and angular velocity of rotating machine and the result is plotted on the monitoring screen.