Computerized Maintenance Management Systems (CMMS) software is an incredibly valuable tool for organizations that perform maintenance across various industries to decrease repeatable failures using knowledge management system. In this paper CMMS software is properly set up to investigate maintenance of gasoline Outboard Engines. Firstly new CMMS concept is introduced with its implementation method. Then failure status of Outboard Engines are evaluated for root causes analysis. Results show that 70% of failures were done due to two factorsthat have good agreement with Pareto principle. Finally life of Outboard Engine is improved more that 350% using some technical prevention with training activities.

The present study investigates the effect of using exhaust smoke extractors as an alternative to traditional manifolds in a spark ignition Engine designed to maximize Engine power. To investigate the effect of the extractors on the Engine performance and selection of superior design, the proposed geometric model of proposed manifolds in a numerical simulation process has been investigated and after optimization has been constructed and installed on the Engine. At the next step, the Engine was experimentally tested in the test cell. Results were compared with the base Engine. It was observed that the designed exhaust extractors would increase the maximum Engine power up to 15%.

Marine diesel Engines are in the heavy duty diesel Engines group with high output power. These Engines have wet liner sleeve that cooling water surrounded it. The cooling heat transferred to space water. The Engine combustion in one side and cooling water and liner interaction at other side create different physical and chemical phenomena. Liner cracking and fracture is probable phenomenon and have different reasons such as over thermal stresses, cavitation or corrosion. These failures cause to general Engine overhaul and liner replacing. This paper presents the study of liner cracking of V12 Marine diesel Engine. The results have shown that the increasing of the cooling water temperature accelerates the liner fatigue and cracking. Liner corrosion and cavitation have additional effects on this failure.

In this article, the process of changing a turbofan Engine to an Engine for use in Marine transportation is investigated. From the production power of the modified Engine, it is possible to supply the propulsion power and power needed by boats and ships. In the first stage, the turbofan Engine is simulated, and after validation with the original model, the fan is removed from the turbofan Engine. The changes caused by removing the fan are studied on the Engine components and then by applying the new conditions, the output power of the Engine derived from the Engine is calculated. In the following, with the installation of the flow guide vane, new conditions prevail over the downstream components of the Engine. In this case, by applying the new conditions, the Engine output power is evaluated along with other quantities. According to the obtained results, after removing the fan from the turbofan Engine, the efficiency of the compressor decreases, but with the installation of the flow guide vane, this loss is compensated and the output power of the Engine is increased. Also, the effect of increasing the inlet temperature to the Engine is studied in two cases without the flow guide vane and after its installation. Based on the results obtained in this part, the flow guide vane increases the production power and reduces the specific fuel consumption in different modes.

In this article, the failure of a heat exchanger during its operation in the Marine environment has been analyzed. This heat exchanger was used for cooling the oil in a Marine diesel Engine. Based on the existing failure history, damages in Engine components were observed after 89 hours of Engine working due to the leakage of the sea water to the oil. For the objective of the failure analysis, each component was investigated under the stereo optical microscopy and the scanning electron microscopy (SEM). The diameter of pits was also recorded as 8 micrometer. Besides, the chemical composition of corrosion products on the surface and in pits was additionally analyzed with the energy dispersive Xray spectroscopy (EDAX). Results indicated that two corrosion mechanisms were failure root causes of leakages, including the crevice corrosion and the pitting corrosion. In such situation, in the Engine, the oil and the sea water in tubes of the heat exchanger mixed and decreased the oil viscosity and damaged the oil film on crankshaft bearings, and finally caused damages of the Engine.

The main responsibility of an Engine mount as a component which attaches the Engine to chassis is control and absorption of different resources of vibration. Design process of Marine Engine mounts is one of main issues in the recent years in Marine industries. Hence, a deep study in diverse design methodologies and performance analysis would be necessary to suggest an appropriate process for Engine mount design. This study based on researches on design methods, suggest design and selection algorithm for Marine Engine mounts in four steps: primarily design, conceptual design, detail design, and finally performance assessment. Afterwards, the suggested process will imply for an internal Marine Engine mount with 200 hp. Based on achieved results, the final designed Engine mount for this case in critical situation will have safety factor of 2. 1 in static analysis and it also have a desired distance from excited frequency in frequency analysis. Finally, dynamic modeling results for this Engine mount will be presented based on designed GUI by research team.

This paper presents energy and exergy analysis of the power generation system of a 2700 kW Marine diesel Engine. The power generation system is consisted of diesel Engine, turbocharger, high and low temperature water cooling system, and heat exchangers. Compressed air is passed through the compressor and is cooled using an intercooler by high and low temperature cooling system. In addition, oil temperature is lowered in the oil heat exchanger via the low temperature cooling system.Implementation of exergy analysis leads to identifying critical points with maximum entropy generation. Outcomes of this research can be used in order to improve performance characteristics of the system. Obtained results showed that the exergy destruction in diesel Engine is 41.9% of inlet fuel’s exergy and 86.9% of the total exergy of the system. Although 18% of heat dissipation occurs at the intercooler and oil heat exchanger, they waste less than 1.8% of inlet fuel’s exergy. While the turbocharger plays no role in the energy balance of the system, it dissipates 4.5% of inlet fuel’s exergy.

Many kinds of Marine diesel Engines may not be used before or during the period of maintenance, boat overhaul, cold season, etc. Because some parts of an Engine or its accessories are not corrosion resistant and during the preservation period, when the Engine is no smeared with oil or any protective substance, it is required for the diesel Engine to pass a process to ensure its good health. This paper presents a root cause analysis of corrosion in a Marine diesel Engine liner after years of preservation. So at first, methods of Engine and component protection are presented in preservation process. Then, by presenting a diesel Engine liner corroded during the preservation process, the effect of careless and inappropriate preservation is assessed. Results show that not complete discharge of cooling fluid from the space between liner and cylinder block and also ambient humidity entrance into Engine compartment due to tearing of aluminum protective foil are the main reasons of atmospheric corrosion in this Marine diesel Engine liner.

A Marine gas turbine rotating disk is one of the most critical components which operates under nonstationary varying mechanical and thermal loads. In this research، the homotopy method is used for stress analysis of rotating disk subjected to thermal load. Apply the thermal loading on the disk with exponential thickness distribution by using the homotopy method and Considering the physical and mechanical properties variations with temperature، are the most important aspects of innovation in this paper. Disc thickness variations are considered exponential and the inner and outer rims of disk are considered constant thickness. Due to the use of homotopy analysis method، important and effective parameters in this method are selected and presented. Furthermore، results are compared and validated with finite element code and good agreement of results with this method is showed. Finally، stress distribution in disks with constant، exponential and hyperbolic thickness distribution are considered and compared. The results showed the efficiency and acceptable accuracy of the method for analysis of rotating disk subjected to thermal and mechanical loading.