This paper presents some experimental results of the distance li between the position of first appearance of visible flame and the nozzle tip and the flame growth in a diesel spray using a constant volume combustion chamber. The first visible flame appears at the turbulent mixing part of the mixing flow region of a spray. The distance li is dependent on the initial pressure po and the number of nozzle holes, but independent on the initial temperature, the oxygen concentration of the charge and the injection quantity. The relation between li and po can be presented by the following experimental expression: li∝pom (m≅-1) . The flame growth speed during pre-mixed flame burning period in the diffusion burning is nearly proportional to the oxygen concentration, but the initial temperature, the initial pressure, the number of nozzle holes and the injection quantity have little effects on the flame growth speed.
In relation to the whirling of a propeller shafting, many conditions which were neglected in the conventional methods of calculation-more than three bearing supports, elastic support of the bearing section, gyroscopic effect of the propeller, shearing deformation of the shaft, etc.-were employed to evaluate accurately the natural frequency. Then, the following results were obtained: (1) .The 3-point or more support is good to obtain a fairly accurate natural frequency. (2) .The spring constant of the stern tube bearing must be measured as accurately as possible. (3) .The gyroscopic effect of the propeller and the shearing deformation of the shaft have influence on the natural frequency by about 6% and 1%, respectively. Furthermore, an analytical method in which the vibration response calculation could be conducted was established, and its utility was confirmed. Then, it was enabled to calculate the dynamic load acting on the bearing. These developments enabled us to predict accurately the whirling of a propeller shafting at the stage of design, and increased reliability in the vibration problems.