The combustion characteristics and engine performance in both DI and IDI type diesel engines with the different gaseous fuels induced from the intake manifold are systematically investigated. The gaseous fuels tested include paraffin fuels (methane, ethane, propane, and butane), olefin fuel (ethylene), and acetylene.
The results of the experiments show that in the DI engine the specific energy consumption and exhaust smoke density especially at higher loads are greatly improved with increase in the amount of gaseous fuel, while NOx emissions increase for all kinds of the gaseous fuels. In the IDI diesel engine, however, gaseous fuel induction affects engine performance only little.
Severe diesel knocking limits the maximum amount of inducted gas, decreasing with higher carbon number of the gaseous fuel. The maximum limit before knocking in the DI type engine is higher than that in the IDI type.
Laser shadowgraphy analysis shows that soot oxidation in the combustion chamber is promoted with the gaseous fuel induction.

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Drainage of residue quantity from the piping system in chemical tanker during the process of air blowing is examined. The quantity of water remaining in horizontal pipe and pressure are measured under various conditions of initial pressure and volume of air tank, trim, and method to maintain back pressure for each test arrangement of piping of 4-inch and 6-inch bore. A back pressure is maintained by constant pressure valve set at 1 bar and pipe rise to a height of 10 meters at the end of horizontal pipe. It is suggested that the developed constant pressure valve have an equivalent function for practical usage to the 10 meters height pipe. It is also discussed the measures to operate efficiently the stripping system.
Simple model presented for determining the quantity of remaining water in horizontal pipe are compared with experimental data for test arrangement of constant pressure valve, and satisfactory agreements are obtained at higher quantity.

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For high speed diesel engines, gas oil and lighter heavy oil are used in general, but, on account of utilization of alternative energy, and in order to decrease black smoke in exhaust gas, blending of ethanol or methanol gas oil are used and studied recently.
So, the ignition temperature of blended fuels, mixed various ethanols, are measured to analyse the effect of ethanol blending fundamentally.
In this paper, the measured ignition temperatures of ethanol blended fuels including Light Cycle Oil (LCO) are reported to show the effect of ethanol blending on mixture ratio, and to investigate the usage LCO in blended fuel utilizations, which cetane number is not fitted to usual diesel engines.

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This paper describes the discharge coefficient C _d and the critical cavitation number σ_cr in sea water through sharp-edged, bevel-edged and round-edged long orifices.
The ranges of test conditions are 0.39-0.59 MPa for the upstream pressure, 295-355 K for the upstream temperature and 7.7-28.5 m/s for the mean velocity, so that the cavitation number σ=0.11-10.99 and the Reynolds number Re = (2.1-15.4) ×10⁴. Further, the cavitation characteristics of sea water are compared with those of fresh water. And the results are summarized as follows:
(1) C_d and σ_cr in sea water for sharp-edged long orifices agree well with those in fresh water. That is, the difference between sea water and fresh water has little effect on the cavitation characteristics. The same can be said about the effect of sea water temperature on the cavitation characteristics.
(2) As for sharp-edged long orifices, the ratio of orifice length to orifice diameter has an effect on C_d. But the effect in the supercavitating region of σ<σ_cr is different from that in the subcavitating and transient regions of σ>σ_cr. This is because the separated supercavitating cavity exists in the supercavitating region, and it does not exist in the subcavitating and transient region.
(3) The tendency of C_d and σ_cr for bevel-edged long orifice agrees qualitatively with those for sharp-edged one.

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Intermediate Shaft bearings are important support bearings of propulsion shafting. Tightening force of foundation bolts for the intermediate shaft bearing is described in this paper.

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