This paper presents an experimental study of condensation pressure in vent and pool water using single vent tube with various diameter vent caps. Steam mass flow rate increases as the vent cap hole diameter and subcooling of the water. The empirical equation (3) is obtained for the above relations. The maximum pressure amplitude in pool water increases as the cap hole diameter. The dominant frequency increases as the cap hole diameter decreases and as the pool water subcooling increases. The present results of the dominant frequency in the vent tube pressure are agree well with the empirical equations which have been reported by Fukuda and Aya. The pool pressure frequency of condensation oscillation has a low frequency component which has not been investigated by existing studies for the vent tube pressure.
In this paper, the separation performance of corrugated eliminators is investigated experimentally, and the eliminators are all held perpendicular to the vertical upward flow of air laden with water droplets. The plates of eliminators used here are made of polyvinyl chloride, and are approximately represented by the sine-wave form. These eliminators have four different wavelengths of 130, 76, 63, 32 mm, wave amplitudes of 18, 9.0, 8.0, 4.5 mm and gaps between the plates of 30, 15, 15, 12 mm, respectively, and their bending numbers are six. Experiments have been made varing from 0.5 to 3.0 m/s in mean air velocity. In vertical upward air flow, the acceleration of gravity has slightly influence on the separation efficiency and the water-film on the eliminator plate surface has also slightly influence on the pressure loss coefficient, respectively. Obtained separation performances are compared with the results predicted by theoretical analysis which has been presented before.
The stranding avoidance system has been researched and developed steadily as one (1) of sub projects together with all other sub projects under the banner of research and development of so-calld“Intelligent ship” through a joint research by Japan Shipbuilding Research Association and seven (7) Japanese shipbuilding companies for six (s) years between 1983 and 1988. The stranding avoidance system using the electronic chart system was so developed as to have full-automatic functions free from navigator's manual operation. The system obtains the precise own ship's position by radar video matching with digital chart, judges the risk against stranding based on updated digital chart and issues the visual & audible alarm to the navigator. Parametric sonar for detection of obstacles in the water was also developed as a different means from the stranding avoidance system using the electronic chart system. The on-board experiment for the trial product of stranding avoidance system was carried out in 1989 on SHIOJI MARU, which is the training ship belonging to Tokyo University of Mercantile Marine so as to verify both satisfactory operation of main functions and effectiveness as navigational aid for the safe navigation of vessel. This report describes outline of stranding avoidance system and results of the on-board experiments.
This research, based on the data analysis of Bunker oil ( 1327 samples of Residual fuel oil, 553 samples of Diesel oil ) received from each ship in 1989 and on the reports about the results of Fuel oil usage ( 200 examples ), refers to the recent trend that the quality of Fuel oil is becoming lower and its problems observed by ship operators. As a result, this research tells us following facts: 1.The quality of Diesel oil is getting lower and lower. 2.Among all the troubles, the rate of Combustion troubles is increasing far more than that of Purification troubles. 3.When the amount of asphalten contained in the fuel surpasses 6.5 weight%, Combustion trouble will be apt to take place in high probability.