Recently, the third generation synchrotron radiation facility, SPring-8, is shared for industrial use. The hard X-ray in SPring-8 is a very intense narrow beam. Therefore, the stress distribution from the surface to the inside of a machinery member can be measured by high energy X-rays. In this paper, the stress scanning method is explained and the residual stress distribution of the laser-shocked Ti alloy is introduced. In the experiment with high energy white X-rays, the energy dispersive method had sufficient accuracy to measure the residual stress distribution. In addition, the neutron beam has a large penetration depth compared with that of a hard synchrotron X-ray. The stress measurement by neutron diffraction is applied to a large piston pin.
The propulsion efficiency of a ship is affected by the fouling of the propeller and ship's hull surface. Fouled surfaces decrease the propulsion efficiency of a ship, and consequently main engine fuel consumption; this increase is due to the torque-rich condition of the main engine.It is well understood that the coating on a propeller and on a hull can protect the propeller and hull surfaces from fouling. It enables us to maintain the service speed of the ship over long periods. Marine engineers check also periodically note the rpm margin of engine output. In the T.S KAIGI-MARU, three kinds of surface treatment were applied during dry docking and over three years. To determine the most effective treatment, three different kinds were employed, for maintaining high propulsion efficiency. The data was then collected for the rpm margin.In this paper, the fouled conditions of the propeller and hull surfaces were estimated by analyzing the rpm margin, so in order to find the optimum Dry Dock Time.
The governor has been the key component in the operation of the stable-heat engine since the invention of Stevenson's "Rocket". However, concerning the operational management of the marine diesel engine, doubts have been expressed as to whether it is required. Under seagoing conditions and against the always-changing resistance of the ocean, we do continually control the volume of the fuel-oil supply, so as to maintain constant engine speed. On the other hand, this leads to the doubt as to whether harder operations are forced onto marine diesel engines. This project was to return to the starting point and reconsider the definition of the governor's purpose. We focused attention on the idea that it might be better - in terms of both fuel-oil consumption and engine load - to maintain a stable ignition pressure within each cylinder, and then allow the engine's revolutions to vary, somewhat. We stopped the former practice of micro-controlling the amount of fuel oil supplied. We then changed fuel-oil supply comparatively slowly. And although engine speeds vary, the average engine speed remains generally as before. This paper introduces the basic research results gathered from container vessels in the development of a "fuel save mode" control system, one built around the new governor.
With lift flames in a diffusion combustor, there is partially premixed combustion at the base of the flame, and the flames have various flame characteristics, such as extinction and re-ignition phenomena. Elucidating those combustion mechanisms is also useful and interesting from the standpoint of discussing flame stability. In this research, we have examined the characteristics of lift flames observed in a bluff body combustor, and the effects which the behavior of annular air flow have on these flame characteristics. The results showed that there is a hysteresis phenomenon whereby the flame configuration varies under the same conditions during an increase and decrease of the fuel flow velocity. It was found that the range where this phenomenon occurs varies greatly depending on the flow velocity of the annular air. In addition, when the flow velocity of the fuel was fixed and the flow velocity of annular air was changed, the bifurcation phenomenon in the flame form was observed.
Numerical calculations were performed in the investigation of the elasto-hydrodynamic lubrication characteristics of a stern tube bearing; several main characteristic values were determined. When the stern tube bearings are not parallel to the propeller shaft, the magnitude of the maximum oil film pressure, generated in the bearing, increases significantly. The magnitude of the maximum oil film pressure generated is greatly affected by the attitude angle of the shaft. As the attitude angle of the shaft is varied between 90 and 180 degrees, the maximum oil film pressure gradually increases. If the eccentricity at the centre of the bearing, and the angle of the shaft centre relative to the bearing's centre, and the attitude angle of the shaft can be determined, then it is possible to quantitatively determine the maximum oil film pressure. This, by taking the elastic deformation of the bearing into account, as described in this paper.
Generally, crack shape which exists in a three-dimensional structure, can be approximated as part of an elliptical crack. High precision evaluations of the stress intensity factor are necessary for the prediction of growth, and unstable fracture of the crack, in such a structure. However, it is difficult to obtain the high precision stress intensity factor if element subdivision is not made fine. This, in the singularity vicinity; such as a crack front. In general, numerical methods for analysis, use such as the Finite Element Method or Boundary Element Method. Also, using general numerical method for analysis, the calculation time becomes very large, to analyze interference problem of the crack group, requiring complicated element subdivision. By using Finite Element-Alternating Method, it is possible to obtain the solution with good accuracy and without completely modeling the crack.In this study, we evaluated by this method, the interference degree between a surface crack and the oil hole in the crank shaft.