Equations for calculating the flow distribution of the dividing header system which is composed of a dividing flow header and parallel branch pipes, and for one of the combining header system which is composed of a combining flow header and parallel branch pipes are derived respectively. The flow distribution factor σd and σc given by σd=ηd/Rm2d, σc=ψn/Rm2c introduced in those equations are dimensionless numbers which control the flow distributions of the dividing header system and of the combining one respectively, where ηd is the diffuser factor of the dividing flow header, ψn is the nozzle factor of the combining flow header, R is the resistance coefficient of the branch pipes and md, mc are the cross-sectional area factors of the dividing and the combining header systems. The flow distributions of the header systems calculated from those equations are in good agreement with the experimental results. The factors ηd in σd and ψn in σc characterizing the flow states in the headers are formulated from the analytical models and are evaluated from the experimental data respectively. Pressure distributions calculated from the data of single branch pipe are not in agreement with pressure distributions measured along the headers.
In the reliability engineering, it has been very important to estimate the lifetime distribution of the replacement parts of systems from the field data. But, the field data consist of times to failure on failed units intermixed with running times, called censoring times, on unfailed units. Such data are quite common and results from (1) removal of units from use before failure, (2) loss or failure of units due to extraneous causes, and (3) collection of data while units are still operating. The field data of marine use mechanical units have also such characteristics as described above. Consequently, it is very difficult to obtain the true estimation of lifetime distribution from such censored data. So far, the authors have qualitatively investigated MTBF, failure rate, repair distribution and so on of the repair units from the field data by using the shape parameter m of the Weibull distribution. But, the graphical method by the Weibull probability paper is not strictly applicable to censored samples without modification. In this paper, first, the shape parameter m of the Weibull model is theoretically discussed from the viewpoint of the mean and variance of this model. Next, the new estimation method of this parameter is proposed on the basis of the estimation principle of the maximum likelihood function introduced by A. C. Cohen. Finally, the usefulness of the newly proposed method is illustrated by using the censored data.
The stirling engine has advantages in regard to multi-fuel capability and exhaust emissions. Recently with increasing social demands such as energy conservation and environmental protection, this engine may have potential replacement for conventional piston engine in future. But the stirling engine has many problems that are posed by aerodynamics flow losses, heat transfer of working gas between expansion space and compression space, seal of working gas and frictional losses. Many results were not presented so much yet. So, we have manufactured for trial a single acting small stirling engine with pressurized crank case to evaluate the performance, with He gas or N2 gas as working gas. A series of characteristic test was done and influence of each factor on engine performance became clear.
The research is started with the object of finding the factors that influence soot formation by the temperature reduction in the flame, when added water is changed under the condition of the fixed spray quantity of kerosine, flame shape and size. It observe how soot concentration is governed by the low temperature reactions arising from atomized water, and at the same time measured the temperature distribution and the concentration of various gas species, to jet fuel (kerosine) from the inner tube and water from the outside tube respectively and make a jet burner with air. Finally, the suppression of soot formation occurs mainly in the region of the nozzle neighborhood, suggesting that low temperature pyrolysis reactions are the dominating reason.
Model studies of oil containment barriers were conducted in an open channel of 30 cm in width and 45 cm in depth. Currents up to 40 cm/s were used with different oils. Water current speed was measured by a calibrated vane-type turbine meter. Acryl viewing windows in both sides of the tank permitted observations of the flow characteristics. The incipient oil drops from barriers were observed using different oils. With the current set up to about 20 cm, oil was poured slowly onto a flat plate just below the water surface to prevent droplet formation and penetration into the flowing water. The length of the oil slick and some oil thickness were measured along the tank centerline after the oil had “piled up” into the barrier. A simple analysis of the oil slick thickness was made, referd to the current speed and densities.
According as the micro-computers are recently applied to the industrial world, the Specification is gratified by not the customary combinations of the individual parts, but by the Software, regarding the computer as its seat of a logic circuit. This is proper method to raise the economical nature and flexibility on the Specification, and that maintain the quality and confidence at high level as a final product. This paper discribles the principal method for the Software Test, and in the system how to select and determine the order of equipments, which should be multiplied to raise the valuation of confidence most reasonably within the designated construction cost.