Regulations on sulphur emissions for coastal areas will soon necessitate ships to operate on low sulphur fuels. In this article the consequences for engine operation on low sulphur fuels are described. Adherence to a few operational rules and recommendations can ensure trouble-free operation of engines operating on low sulphur fuel, as there would be only minor implications for the fuel and lubricant systems. Yet there are certain challenges, the industry will be confronted with, when the emission legislation will be even stricter in future.
A flammable material such as fuel oil or lubricating oil can often be the cause of a ship's fire disaster. There have been many studies of pure materials, such as benzene or alcohol, but very little of practical use is known about self ignition phenomena of fuel oil and lubricating oil, as far as the authors are aware. We examined the ignition characteristics of gas oil, marine diesel oil, heavy fuel oil, and lubricating oil, and reported the characteristics of these flammable materials. In this study, especially in the part using turbine oil, we tested by the same method used previously. Because new information was found, we report the new portions.
Oil outflows from sunken ships, e.g., the Nakhodka and Chikubu-maru, have been reported in recent years. The purposes of this study were observation of C heavy oil gushing out behavior in freshwater and seawater at atmospheric pressure and construction of its visualization system in a high-pressure vessel which can pressurize water up to 40 MPa. One motion of C heavy oil gushing out was continuously belt-like, and the other motion was intermittently spherical. Outflows in seawater were bigger than those in freshwater. The visualization system for viscous fluid gushing out behaivior consisted of a color CCD camera, LED, and stepping motor. The system successfully recorded intermittent spherical gushing in the vessel. The oil from a sunken ship would not cause a big outflow unless the sunken body sustained a large shock or earthquake.
Noise from a ship at anchor sometimes poses problems to humans in the vicinity. The sound from the exhaust of the main generator is the main cause for the noise. This can be managed by installing an active silencer to the main generator. All the noise sources from the ship were analyzed after installing the silencer. The extent of the noise in the ships vicinity were calculated by applying a ray tracing method to all noise sources. The calculation was confirmed as precise, as it indicated 3 dB (A) . Future studies will explore noise from an anchored ship in relation to noise.
A marine propulsion system consists of an engine, a propeller and a shaft, and the hull. Its dynamic characteristics vary according to the system states. In order to design a highly developed control system and to achieve a safe navigation, it is important to understand the properties of such a complex system. In this paper, the mathematical model of a marine propulsion system is formulated and its dynamic characteristics are analyzed. An optimal trajectory planning so as to accomplish a smooth state transition and a quick system response was investigated on the basis of the previous system analysis. A performance criterion to characterize the system behavior is reasonably defined and the procedure for obtaining optimal trajectories under an engine torque limit has been formulated. An algorithm for obtaining optimal solutions was developed and simulations were conducted upon a general ship control model to evaluate the newly designed system. It was found that a marine propulsion system can be effectively operated under the optimal trajectories.
Effects of split injection on combustion and emission characteristics of a D.I.Diesel engine were investigated. Keeping the injection pressure and total injection period constant, different amounts of fuel were injected between the two injection pulses. The in-cylinder pressure was analyzed and the properties of the combustion process are discussed with the engine-out measurements. The distribution of the vapor and liquid phase concentrations in the splitting fuel spray injected into a high-pressure and high-temperature vessel were measured by means of the Laser Absorption Scattering (LAS) technique. The mixture properties obtained by LAS measurements were correlated with the engine experiment. The results account for the effect of split injection on the combustion and emission characteristics.