著者
吉川 文隆 矢野 昭彦 内田 幸宏 藤田 健二 川添 強 佐田 裕之
出版者
The Japan Institute of Marine Engineering
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.43, no.1, pp.123-129, 2008-03-01
参考文献数
7
被引用文献数
1

Propeller shaft diameter of ferries becomes larger in conjunction with requirements of higher vessel's speed and CPPs (controllable pitch propellers) . Thus, it may lead into a tendency to reduce the life duration of stem tube bearing under seawater lubrication. Wear of the propeller shaft sleeve, i.e. bronze alloy, is typically greater than that of the rubber bearings, with triangularly shaped craters appearing on the sleeve surface.<BR>In this paper, we describe the investigation of used sleeve sample taken from an actual vessel, as well as the wear characteristics of bronze alloys conducted under the corrosive wear condition which is equivalent to actual ferry service. The results indicated that corrosive wear was the main cause of sleeve wear. Comparing between the amount of wear in seawater and the one in distilled water, the influence of corrosion on sleeve wear was found to be substantial. Additionally, the craters are considered to be formed by the action of erosion corrosion
著者
久保 博尚 長瀬 通昭 板谷 芳樹 大森 丈治 吉岡 勝
出版者
The Japan Institute of Marine Engineering
雑誌
日本舶用機関学会誌 (ISSN:03883051)
巻号頁・発行日
vol.22, no.4, pp.263-270, 1987
被引用文献数
1

Various attentions have been paid to improvement of propeller efficiency. Among these devices, the free rotating propeller (vane wheel) to be fitted additionally behind conventional main propeller is the most attractive one. However the design method, blade strength, etc. of the free rotating propeller are not specified.<BR>The authors designed the free rotating propeller for the ship by applying the momentum theory and the blade element theory that are used for designing the hydraulic machineries. In this report, the design accuracy is compared with full-scale measurements and as the results, the following conclusions are obtained.<BR>(1) The calculated revolutions and energy saving rate of the free rotating propeller show a similarity to those of measurements.<BR>(2) Measured energy saving rate is 6-8.5% at same speed condition.<BR>(3) The mean blade stress is 2.6kgf/mm<SUP>2</SUP> {25 MPa} and the fluctuation of blade stress for a rotation is 8.8kgf/mm<SUP>2</SUP> {86 MPa} in peak-to-peak value.<BR>(4) The pressure fluctuation caused by main propeller is reduced by 20% at the blade frequency components.
著者
渡辺 専治 伊藤 勝行
出版者
The Japan Institute of Marine Engineering
雑誌
日本舶用機関学会誌 (ISSN:03883051)
巻号頁・発行日
vol.30, no.9, pp.668-673, 1995-09-01
参考文献数
7

Recentry, engine troubles caused by water and mold in gas oil occur in pleasure boats, small training ships and co-gene plants, etc diesel engine systems. Mold stops strainer of diesel engine systems immediately and causes engine troubles.<BR>For preventing engine troubles, "Protect mold and water solubilizer" being added in gas oil and controling mold slduge is necessary. It is more simple and econo mical. As follows, we state "Protect mold and water solubilizer" deveroped by our Company.
著者
ガロワ ジャック 栄家 達也
出版者
The Japan Institute of Marine Engineering
雑誌
日本舶用機関学会誌 (ISSN:03883051)
巻号頁・発行日
vol.22, no.12, pp.799-807, 1987

This paper shows that the new CODAD solusion using 4 engines and 2 propellers is interesting for a 2500 tons frigate, thanks to a new generation of diesel engines with low compression ratio and two stages turbo charging process (SEMTPielstick PA6BTC engines) and that the frigates up to 4500 tons and even 5000 tons can be built in the same way with the following advantages, that is, noise detection improved thanks to the elastic mounting of complete propulsion units, infrared detection improved, compact and independent propulsion units, very good survivability, narrow inlet and exhaust ducting, large flexibility of operation and large overhaul interval and easy maintenance on board by crew, etc..
著者
三輪 誠 三村 治夫 阿部 晃久 西尾 茂 武田 実
出版者
The Japan Institute of Marine Engineering
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.44, no.3, pp.470-476, 2009-05-01
被引用文献数
2

Pathogenic and fecal bacteria, such as Vibrio cholerae and Escherichia coli, possibly invade via seawater. This may expose marine engineers to an intrinsic risk of infection when they carry out routine maintenance. We therefore investigated, following the voyage, the seawater taken into a ship's engine-room. As for the populations, they varied from 102.9 to 105.9 colony-forming units (cfu) ml-1. A correlation coefficient between the population and the in situ seawater temperature was 0.71, 0.30, and 0.068 for the samples taken from calls facing to the ocean (n = 6), the Inland Sea (n = 12), and the coastal area around the Pacific Ocean (n = 16), respectively. An occupational ratio of Vibrio sp. population increases when the seawater was retained for more than three months in the condensers for the air conditioner and the drain cooler. Although three strains were detected from the drain cooler, those of which had ability to make yellow-colored colonies on a selective plate at 37°C and left for 6 months. It was identified as to be Aerococcus viridans. In that species, the lobster pathogen is included, but nothing human. So far examined is pathogenic V. cholerae, which was not detected in all the samples taken from the engine-room. These results indicate that the possibility of infection of marine engineers to be quite low when they do the maintenance on board in the coastal area and the Inland Sea of Japan
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

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
佐川 隆一 加藤 幸三 松田 裕昌 蔵田 親利 森 鋭和
出版者
The Japan Institute of Marine Engineering
雑誌
日本舶用機関学会誌 (ISSN:03883051)
巻号頁・発行日
vol.8, no.9, pp.697-708, 1973

近年, 舶用主機の大容量化に伴い, ボイラ燃焼室の発熱負荷は大幅に増大している.これにより加熱管の局所過熱や熱計算法の再検討等の問題が起きている.これらの問題点に関する情報を得るために, 自然循環ボイラ (蒸発量30T/H) を用いて実験を行なった.<BR>本報告は, これらの問題に大きな関連を持つ燃焼ガスのフローパターン, 炉内温度分布, 熱流束分布等の実験結果について示す.<BR>まず, 炉内フローパターンの観察を5孔ピトー管, 発煙筒等を用いて行なった結果, 以下のことが判明した.<BR>(1) フロパターンは燃焼時でも非燃焼時でもほとんど同様である. (2) 火炎形状は卵形であり, 燃焼室の形状には無関係である. (3) 火炎と底面の間の狭い領域に強い逆流が存在している. (4) 上部空間には炎がなく, ガスは停滞している.<BR>次に, 吸引式温度計を用いて炉内温度分布を測定した結果, フローパターンの計測並びに火炎形状の観察結果と良い対応を示した.最高温度は火炎のバーナ寄り約1/3の所で記録された.燃焼室出口ガス温度は計算結果と大体一致した.<BR>最後に, 手製の熱流束計を用いて熱流束の分布を測定した.本装置は全熱流束だけでなく, ふく射成分のみの分離計測も可能である.最大熱流束は火炎の中央で記録され, その値は燃焼室平均値より67~84%大きかった.その結果, 各々の水冷管の熱吸収割合にはかなり大きな差が現われた.この差異はボイラの循環や安全性に大きな影響を持っているであろう.<BR>全熱流束に対するふく射成分は2/4負荷時に約84%であった.
著者
鈴木 清
出版者
The Japan Institute of Marine Engineering
雑誌
日本舶用機関学会誌 (ISSN:03883051)
巻号頁・発行日
vol.34, no.5, pp.320-327, 1999-05-01

The ship have completed the docking survey at Singapore. After twenty hours in sailing for loading port, the main deisel engine occurred explosion in the scavenging air manifold. And then the main engine stopped by auto.device. But it was not re-start. Both of the aux. blowers damaged at impeller and casing. The ship was staying for a week at emergency anchorage. The aux, blowers changed completely with elect. Motors. It caused that much accumulated oily mist in the scavenging air manifold by the drain pipe be blockade was ignited.
著者
吉川 文隆 内田 幸宏 藤田 健二 矢野 昭彦 川添 強 佐田 裕之
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.43, no.2, pp.258-264, 2008

The previous report described the corrosive wear on propeller shaft sleeves, made of bronze, in seawater-lubricated stem tube bearings. Accompanying is the occurrence of craters on the sleeve surface due to the action of erosion corrosion. As a countermeasure, based on the mechanism, this second report will provide the development of a catholic protection bearing, what prevents corrosion of the sleeve surface and reduces wear. Using anodes installed in some of the water channel grooves of the rubber bearings, this method is characterized by intermittent protection at best, and protection conditions were investigated by means of fundamental testing and using bearings of 140mm in diameter. As a result, a current density of 8A/m<SUP>2</SUP> was found to protect the sleeve from corrosive wear. Cathodically protected bearings were also applied to bearings of 500mm in diameter and equipped for a ferry vessel. The results are presented here in terms of bearing design, trial running, and successful reduction of wear during actual in-service use.