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Abnormal fuel injection in light-duty, high-speed diesel engines was analyzed by developing a mathematical simulation program. It predicts the transient hydraulic phenomena and the dynamics of the mechanical components by applying the injection system design data. The results show the existence of marked changes of injection quantity against residual pressure, cavity content and pump speed, in the case of abnormal fuel injection. Closer observation reveals that the injection rate change from two-stage to one-stage causes a marked change in injection quantity.

The improvement of the torque converter performance necessitates an optimized design of the torque converter stator blade on the basis of a full understanding of the internal flow conditions. However, it is difficult to analyze the flow experimentally or theoretically because the three elements (a pump, a turbine, and a stator) rotate at different speeds and the flow circuit and the blade shapes are complex. Enough explication of the internal flow has not yet been made. This research has developed a new method of calculating the torque converter performance by taking the stator blade profile into consideration. The internal flow through the torque converter stator can be treated as a two-dimensional flow, and here the flow was analyzed as a potential flow. The analysis of the torque converter stator blade was made as follows.

The importance to minimize vibrations and noises in every part of a vehicle is widely recognized. Clutch pedal vibration and the associated room noise are also the targets to be tackled. The clutch pedal vibration is attributed to flywheel vibration, which is converted into pressure pulsation in the clutch hydraulic system. Therefore, clarifying pressure pulsation transfer characteristics in the hydraulic system is very important in reducing the vibration and noise during clutch pedal operations. In this study, the pressure pulsation transfer characteristics were simulated by the matrix method, whose results agreed well with the experimental data. The simulation has made it possible to quantitatively predict the effects of the dimensions of the hydraulic system on the transfer characteristics, which have been known only through experimental analysis.