Recently, providing a controllable pitch propeller (CPP) has increased for convenience of maneuvering a ship or capability of using the shaft generator, and the conventional control algorithms of these CPP system are comparatively simple. However, CPP system has essentially the capability of controlling two freedoms because there are two input parameters of a propeller pitch angle (P) and a regulator handle position (R) in the system. One freedom must be used for controlling the ship speed which is the most important controlled value for vehicles. Another freedom should be utilized positively to improve or optimize some useful performances such as fuel consumption ratio (be), NOx emission and so on. These utilization is accomplished by controlling P and R simultaneously which is called the consolidated control. In the study, “be” or “be” plus NOx was adopted as the performance index of the utilization. There are two types of the consolidated control, “On-line type” and “Off-line type”. In this study, On-line type consolidated control was focused and investigated by simulation. Results showed the usefulness of this consolidated control.

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The effects of change of swirl chamber shape on engine performance are investigated for the design and development of a I.D.I. Diesel Engine. The changed factors are a wall angle of the swirl chamber, throat area and throat length in the indirect combustion chamber. The main effects of this work are that a gaseous emission, NOx reduced by decreasing the wall angle ( Θ1) of the swirl chamber, and that a smoke reduced by decreasing the wall angle ( Θ2) . And, by the decrease of the throat area reduced a smoke and specific fuel consumption at the high speed range.

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There are several stages of Cavitation phenomena in the flow around butterfly valves. The cavitation stage such as cavitation inception, supercavitation inception, cavitation damage inception, choking (or flashing) cavitation occurs for the various valve opening angles. In this paper, these cavitation stages were theoretically predicted for valve loss coefficient. The cavitation prediction was performed by applying the free streamline theory, where the relation between the loss coefficient and the critical cavitation factor were formulated. As for the experiment, the cavitation inception and critical supercavition were obtained from the vibration intensity rising and the noise level rising, and the flashing cavitation was observed by means of flow visuarization. The theoretical predicted characteristic curves and these experimental results were compared, and agreed very well with each other.

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Many marine organisms attach to the hull and propeller surface of anchored ships. This attachment of marine organisms increases the frictional resistance of the propeller, and lowers its rotational frequency. Although anti-fouling paints for the hull prevent the attachment of fouling organisms, they contain poisonous compounds such as organic tin and cuprous oxides.
Since marine organisms cannot attach to the propeller during voyage, safe, easy and effective method to prevent attachement in anchored ships is desirable. To date, some propeller-coating paints without the poisonous compounds have been examined and developed. However, the paints have not yet been holding perfectly. In our preliminary experiment, we observed that the marine organisms were seen attached everywhere on the test plate except the scratching part. The electrolytic current, therefore, is feasible to prevent the attachment of marine organisms to the propeller. The electric technique does not pollute the marine environment, unlike the anti-fouling paints. This techique may be useful not only to ships but also to many other structures in the ocean, such as buoys, pontoon bridges and rigs.

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We have developed a novel catalyst for a selective catalytic reduction (SCR) of NOx with ammonia. The catalyst can be applied for a marine use. It is composed of the natural zeolites and the metal oxides, and its activity of NOx reduction is higher in a low temperature (150-250°C) than that of commercial SCR catalysts. In addition to this high activity, the oxidation activity of SO₂ is low, in comparison with the commercial one: little amount of ammonium sulfate forms. Therefore, the catalyst solves the problems of corrosion, plugging of a pipping or a heatexchanger, and the catalytic activity-decrease to be due to a scaling of a ammonium sulfate on the catalytic surface.

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This paper is the reports of operation test using water-emulsified fuel. We used a high-speed diesel engine with 250mm-cylinder bore, 250mm-piston stroke.
Tests were carried out varying the water-content of emulsion (0-90%) and the dimension of a fuel pump (22-26mm) consequently, following results are obtained.
(1) Fuel consumption is improved by adding water to fuel oil.
(2) The injection pressure of water-emulsified fuel rises linearly in proportion to water-content.
(3) The temperature of the cylinder liner rises linearly in proportion to water-content.
(4) NOx decreases linearly in proportion to water-content.
(5) The reduction rate of NOx or fuel consumption by water-content is independent of the dimensions of a fuel injection system.

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