The size distribution of single soot particles (the fuel was gas oil) in single fuel spray combustion by a rapid compression machine was measured with electron micrographs and calculated by the small angle scattering method of X-rays. It was studied in relation to the compression ratio of a combustion chamber and the volume of fuel injection. The size of crystallites in a single soot particle was measured with an X-ray diffractometer. The results of this experiment are summarized as follows: (1) The size distribution of single soot particles is not affected by the compression ratio and the volume of fuel injection. It is the same as the distribution of single soot particles in a wick flame. (2) A single soot particle is a sphere of 300Å in diameter in the maximum distribution. (3) The size of crystallites in a single soot particle is 13.96Å. It is 1/15-1/25 the size of a single soot particle in the maximum distribution examined by the electron micrographs (×12300) . (4) The size distribution of single soot particles in this experiment shows much the same tendency as the one calculated by Guinier plot method. The results of this experiment indicate that a soot is composed of many spherical single soot particles and that it is formed by a great many microscopic cristllites. As described above, the essential structure of soot particles is one of the important factors in the investigation of soot formation in combustion processes.
This paper describes our solutions to several problems of Stirling engine simulations which has been applied to the engine design. We made a 0.2KW Stirling engine and measurement system, and examined differences between both data from experiments and from simulations. The computer simulation models selected for the evaluation are as follows: — Five-space model, where state of working gas is assumed to be uniform within each four heater, cooler and cylinder spaces (eleven differential equations were calculated) . — Adiabatic model, which is the same as Schmidt model except adiabatic changes occur in an expansion and a compression space. Cyclic variation amplitudes of a working gas temperature and pressure are shown to be greater when calculated by computer simulations. We solved that the differences were caused by the lack of a space division especially in the regenerator space. By using a model with 37 spaces the differences were greatly reduced.
The maintenance works for merchant marine engine plants could be classified into the inspecting action, the preventive maintenance, the precautionary maintenance, the sweep action and the administrative work from the marine engine maintenance work reports. Although the above maintenance works were affected by the classification of main engine; diesel main engine or turbine one or the classification of main engine licenser and their plant subsystems, there has not always been enough discussions for the engine maintenance works of ship which are the general cargo ship, the container ship, tanker and the other bulk carrier. Then the total value 36×104 occurrences of the engine maintenance works which are the inspecting actions, preventive-, and precautionary maintenances are surveyed from marine engine maintenance work reports submitted by the three classifications of ships; the general cargo ship (16 vessels), the container ship (11 ones) and tankers (17 ones) during 72.3×104 propelling hours of the four years from Oct. 1970 to Sept. 1974. According to the percentage of manning index of the above three classifications of maintenance works, the following three maintenance modes are ascertained for above three classifications of ships; (1) Maintenance mode (CM) : Tanker, the value of manning index of corrective (precautionary) maintenance is more than about 30 [%] . (2) Maintenance mode (PM) : The cargo ship, the value of manning index of preventive maintenance is more than about 70 [%] . (3) Maintenance mode (IM) : The container ship, the value of manning index of inspecting action is more than about 10 [%] .
One of the major concerns regarding lubricants for medium speed diesel engine is how alkalinity of lubricant influences on lubrication performance under high sulfur fuel operation. In the present study, the tests were conducted using Mitsui 1L42X test engine together with other laboratory instruments to investigate the influence of TBN of lubricant on thermal stability, piston ring wear, detergency, and physical properties of used oils. The engine test results suggest the presence of suitable TBN which minimizes the piston ring wear. Higher TBN oils give less piston deposit and less insoluble product in used oils. The thermal stability in differential thermal analysis is improved with increasing of TBN while panel coker test result shows minimum deposit formation at medium TBN. These results are considered to be caused by the action of high alkaline detergent additive in the lubricants and the combustion products including acidic products from high sulfur fuel.