著者
蔦原 道久 木村 雄吉 盧 基徳
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
日本舶用機関学会誌 (ISSN:03883051)
巻号頁・発行日
vol.23, no.8, pp.474-479, 1988-08-01 (Released:2010-05-31)
参考文献数
14
被引用文献数
2 2

A two-dimensional model of the Weis-Fogh mechanism, which is a mechanism of hovering flight of small insects, is applied to ship propulsion. A model of the propulsion mechanism consisting of one or two wings in a square channel is proposed. The thrust and the drag on the wing, which are defined, respectively, the force in the direction of progress of the ship and that of movement of the wing, are measured. The propulsive efficiency is calculated and is high when the moving speed of the wing is small compared with the advancing speed of the ship. A model ship equipped with this propulsion mechanism is made and working tests performed. The applicability of this propulsion mechanism to actual ships is expected to be good.
著者
武田 幸男 坂本 研也 根岸 道明
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
日本舶用機関学会誌 (ISSN:03883051)
巻号頁・発行日
vol.10, no.2, pp.160-169, 1975-02-01 (Released:2010-05-31)
参考文献数
11

大容量化する船舶電源装置では, 発電機を常時並列運転することが一般化してきた.並列運転時に発生する無効横流を抑制するために横流補償装置が用いられるが, 負荷時には母線電圧を低下するように作動するから, 従来は横流補償率を大きくすることが出来なかった.それゆえ, 低い横流補償率の場合は並列運転系統の安定度が低下し, 負荷の増加によって乱調を発生する場合がある.本文は, 大きな横流補償抵抗と, 差動変流器 (DCT) を組合せた差動横流補償装置 (DCC) を用いて.極めて安定で, かつ, 電圧変動率の小さい電源構成が得られることを示したものである.すなわち, 差動変流器を横流補償回路に導入した場合の動態安定度と定態安定度の解析を行なって.動態安定度は差動変流器の有無に関係しないこと, 及び, 横流補償度 (横流補償率とAVRの制御ゲインの積) の最低制限値が定態安定度から求められることなどを明らかにした.又, その結果に基づいて, 差動横流補償装置の設計方針を示し, 単独・並列運転のいずれにおいても母線の電圧変動率を±1%以内とする安定な電源設計例を示した.本装置はすでに多数の船舶に装備され, その効果は確認されている.
著者
畑中 義博 大西 正幸
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
日本舶用機関学会誌 (ISSN:03883051)
巻号頁・発行日
vol.18, no.4, pp.352-358, 1983-04-01 (Released:2010-05-31)
参考文献数
13
被引用文献数
1

The reduction in fuel consumption and NOxemission have been confirmed with burning of emulsified fuels in diesel and boiler plant so far. Fuel savings from four to seven per cent have been achieved, when burning water-in-heavy oil emulsions in marine diesel engines.In the evaluations of emulsified fuel combustion, the following parameters should have been considered: water content, particle size, distribution, stability, viscosity, specific gravity. These fundamental data with emulsified fuel have been lacked.Thus investigations have been given to these parameters which affect conditions of combustion.
著者
一色 尚次 塚原 茂司 崔 甲錫 桑原 孫四郎 杠 好秋
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
日本舶用機関学会誌 (ISSN:03883051)
巻号頁・発行日
vol.12, no.9, pp.705-714, 1977

Firstly, a theoretical comparison of performance of Stirling engine cycle of various types, the Rombic type, L (or V) type, and Inversed T type (I-T type), is shown in this report.<BR>By the results, the non dimensional power &Delta;<I>pm/pm</I> is highest for the I-T type with adequate value of <I>x</I> (non dimensional volume difference between low temperature cylinder and high temperature cylinder of displacer cylinders) .<BR>Also it is shown that, the weight ratio of gas which pass through regenerator to the total gas is highest at I-T type.<BR>Secondly, an experiment of Stirling engine of L-type by atomospheric air is reported here.<BR>By its results, the power is high when the pressure drop by the regenerator is smaller than 1/10 of mean absolute pressure.<BR>The tendency of performance is known to be proportional with Schmidt theory that uses two region model of constant temperature.<BR>By this study many fundamental knowledge about Stirling Engine is accumulated very much.
著者
堀籠 教夫
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
日本舶用機関学会誌 (ISSN:03883051)
巻号頁・発行日
vol.15, no.9, pp.744-751, 1980

It is not so easy to obtain the failure rate, the lifetime distribution, MTBF and so on from field data, because the field data are so called the incomplete data or the censored data consisting of time to failure for failed units where the failure and the running time are intermixed.<BR>This paper describes mainly the estimation methods and their application to the field data of marine engine system. The Weibull model adopted is a one with two parameters, i.e., the shape and scale parameter.<BR>In particular, we emphasize the estimation methods, that is, the Best Linear Estimation Method developed by N. R. Mann, the Hazard Plotting Method proposed by W. Nelson and the Maximum Likelihood Method by A. C. Cohen.<BR>Then, we illustrates examples of case studies on the censored data.<BR>Finally, we touch on the determination method of the optimal preventive maintenance on the basis of the Weibull model obtained.