著者
Lunde Tore
出版者
公益社団法人 日本マリンエンジニアリング学会
雑誌
Marine engineering : journal of the Japan Institution of Marine Engineering = マリンエンジニアリング : 日本マリンエンジニアリング学会誌 (ISSN:13461427)
巻号頁・発行日
vol.40, no.3, pp.337-340, 2005-05-01

Unlike all cargo ships, liquefied natural gas (LNG) carriers have continued to use steam turbine propulsion plant despite more efficient diesel engine being available. This is because the gas that naturally evaporates from the cargo (called boil-off) is used as fuel for the steam turbines, and until recently there was no other use for it. The ability to reliquefy the gas given off by the cargo now makes it possible to increase the amount of LNG delivered to the discharge port, which is more profitable than using it as ship' s bunker.<BR>Reliquefying LNG and returning it to the cargo tanks means that gas never enter the engine room, adding to the general safety margin. Total separation between cargo and engine room means that the propulsion system and type of fuel used can be chosen freely.
著者
小澤 宏臣 村田 航 坪川 毅彦 吉武 正湛 高品 純志
出版者
公益社団法人 日本マリンエンジニアリング学会
雑誌
マリンエンジニアリング (ISSN:13461427)
巻号頁・発行日
vol.40, no.2, pp.163-167, 2005-03-01 (Released:2010-05-31)
参考文献数
3

「ちきゅう」 (以下, 本船と記す) は, 大水深海域にて科学掘削を行う世界最大かつ最新の掘削船として, 2003年7月に船体部を三井造船 (株) 玉野事業所にて完成させ, 現在, 三菱重工業 (株) 長崎造船所にて, 掘削部の最終艤装中である.ここでは, 本船の船体部の主要部をなす自動船位保持機能について述べる.
著者
西村 章広 脇坂 知行
出版者
The Japan Institute of Marine Engineering
雑誌
マリンエンジニアリング (ISSN:13461427)
巻号頁・発行日
vol.40, no.2, pp.266-272, 2005-03-01 (Released:2010-05-31)
参考文献数
15
被引用文献数
1

A diesel fuel breakup model was developed in the framework of the three-dimensional fluid dynamics code KIVA-3V and validated with experimental data. This breakup model accounts for cavitation bubble collapse energy, turbulent kinetic energy, and aerodynamic forces on the liquid core. The primary breakup time is computed by a balance between surface tension of the liquid core and the breakup forces obtained as aerodynamic force and breakup force based on cavitation bubble collapse. The calculated diameter of the child droplet is based on the liquid core surface wavelength, which is caused by fluctuating turbulence velocities. At the time of primary breakup, a child droplet uses its turbulent energy to determine the ensuing trajectory. Hence, the proposed Cavitation Bubble Collapse Energy Breakup (CEB) model is capable of predicting the spray cone angle. Generation of child droplets as a result of primary breakup continues until all cavitation bubbles have totally collapsed. Subsequently, the Taylor Analogy Breakup (TAB) model is used for secondary droplet breakup. Model predictions of spray tip penetration, spray cone angle, and Sauter Mean Diameter (SMD) have been found in good agreement with experimental data for non-evaporating sprays under high injection pressure.
著者
福岡 俊道
出版者
公益社団法人 日本マリンエンジニアリング学会
雑誌
マリンエンジニアリング (ISSN:13461427)
巻号頁・発行日
vol.48, no.6, pp.847-853, 2013-11-01 (Released:2014-11-01)
参考文献数
10
被引用文献数
1

A bolt heater is frequently applied to tighten large and critical structures with large bolts that cannot be clamped by any other means. In addition, multiple bolts can be tightened simultaneously by using the same number of bolt heaters. When bolt heaters are used for tightening large bolts, they are usually placed vertically because the target bolts are installed in the same vertical direction. In this study, the applicability of horizontally plated bolt heaters is examined to promote its broader use. It is found from tightening experiments that the bolt heater technique can be applied for bolts placed horizontally or on an inclined plane. Based on the experimental results, a guideline is proposed for the cases of bolt heaters used in the above-mentioned manner. It is also shown that the bolt heater technique can be an effective assisting method to JIS B2251, “Bolt tightening procedure for pressure boundary flanged joint assembly”.
著者
塩崎 洋 青木 太郎 清水 悦郎 伊藤 雅則
出版者
公益社団法人 日本マリンエンジニアリング学会
雑誌
マリンエンジニアリング (ISSN:13461427)
巻号頁・発行日
vol.47, no.1, pp.105-110, 2012-01-01 (Released:2013-10-26)
参考文献数
6

A snake is an amazing animal considering that it can make various motions using only its slender body. Many researches on snake-like robots have focused on ground movement. However, aquatic animals such as sea snakes and eels also move in a meandering motion. Considering these facts, the authors decided to develop an autonomous underwater snake-like robot. As an approach to this goal, a sea snake robot was made to examine the basic characteristics of propulsion. In the experiments, three axial force gauges and two cameras at different angles were set on the robot’s head. The frequency, amplitude, and phase difference which constitute the elements of meandering motion were varied, and the movement and forces acting on the robot were measured for both in-water and in-air operation. From the results of experiments, the characteristics of the propulsion force of snake motion water were discussed.