Journal bearings, which are used in all kinds of rotating machinery, do not only support static loads, such as the weight of rotors and load caused by transmitted torque of reduction gears, but are, in addition almost the only machine element that is able to suppress various exciting forces acting on the rotating shaft. As rotating machines have become large and multi-staged, while compactness, high speed, and high output have also been realized in recent years, not only has the bearing load increased, but also the magnitude and variety of exciting forces. Therefore, the role and importance of journal bearings have increased tremendous ly. In particular, for the design of rotating machines with low vibration levels and high reliability, knowledge of the exact characteristic data of bearings, and especial ly of the stiffness or spring coefficients and the damping coefficients of oil films in bearings, is essential. However, the amount of reliable data now applicable to practical design is limited. Through the activity of the Research Subcommittee on Dynamic Charac teristics of Journal Bearings and Their Applications (designated as PSC 28), estab lished and organized in June 1979 through May 1982 within the Japan Society of Mechanical Engineers (JSME), these coefficients, together with static characteris tics, have been calculated and also measured on a number of new test rigs.

Non-uniform combustion, as encountered in diesel and gas turbine engines, furnaces, and boilers, is responsible for the conversion of fossil fuel to energy and also for the corresponding formation of pollutants. In spite of great research efforts in the past, the mechanism of non-uniform combustion has remained less explored than that of other combustion types, since it consists of many, mostly transient processes which influence each other. In view of this background, a group research project, "Exploration of Combustion Mechanism," was established to explore the mechanism of combustion, especially that of diffusive combustion, and also to find efficient ways to control the combustion process for better utilization of fuel and the reduction of pollutant emission. The group research was started, after preparatory activity of 2 years, in April 1988, for a period of 3 years, as a project with a Grant-in-Aid for Scientific Research of Priority Area subsidized by the Ministry of Education, Science and Culture of Japan. The entire group of 43 members was set up as an organizing committee of 13 members, and five research groups, consisting of 36 members. The research groups were: (1) Steady combustion, (2) Unsteady spray combustion, (3) Control of combustion, (4) Chemistry of combustion, and (5) Effects of fuels. At the beginning of the project it was agreed that we should pursue the mechanism of combustion from a scientific viewpoint, namely, the target of the project was to obtain the fundamentals, or "know why," rather than "know how" of combustion.