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In the presented paper, the effect of the heat transfer coefficient on the cylinder combustion pressure has been analyzed. The analysis has been performed by using a simulation model that has been used for the research into the influence of multiple injections on the combustion processes and products in the cylinder of slow-speed marine diesel engines. For the analysis purpose, the combustion nul-dimensional mathematical model has been applied, which was validated by comparing the actual data measured on board a ship and the results obtained from simulations. The paper presents the results of the heat transfer influence comparison obtained by applying formulas for the heat transfer used by Annand, Eichelberg and Woschni. The results are statistically analyzed and graphically presented. The best choice is explained and suggested. [ABSTRACT FROM AUTHOR]

When analyzing the reliability of the complex ship systems, it is necessary to define the reliability of the subsystem components, as well as the reliability of the system as a whole. The diesel engine fuel system has been described as a complex technical system consisting of the passive parallel and partly parallel subsystems connected in series. The reliability of the diesel engine fuel system for one cylinder has been analyzed and so has been the reliability of the diesel engine fuel system as a whole. A higher diesel engine fuel system reliability can be obtained if the failure rate is smaller and the number of parallelly connected components of the redundant subsystems is greater. It has been proved that the reliability of the diesel engine fuel system as a whole is greater than the reliability of the diesel engine fuel system for one cylinder. It is therefore proposed that the choice of a more qualitative component (smaller failure rate) and of a better maintenance must be taken into consideration if the ship reliability system is to be increased. [ABSTRACT FROM AUTHOR]

The more and more rigorous regulations on the environmental protection, as well as the need for a much better fuel exploitation, have raised greater demands on the designer. The development of numerical methods and, at the same time, a computing power growth, makes the checking of new ideas possible, even in the early stage of the engine development. The paper aims at presenting a survey of all the possibilities offered by the AVL-BOOST software produced by the firm AVL from Graz: A graphical interface, that enables the user with only a basic knowledge of a simulation technology to master the computer programme in a very short time, has been described too. A one-cylinder engine model has been presented and its operation simulated. The results thus obtained have been analyzed. [ABSTRACT FROM AUTHOR]