1.When chair seats are arranged front facing, anti rolling efficiency of seats is good but view ability of seats is bad. Then, actual circumstances of the view ability is easily recognized by drawing plans and sections of view estimating line. 2.We coexistence the anti rolling efficiency of seats and the view ability of seats by adopting rotating type gathering seats for 2 persons. That is, when sea condition is hard, we get good anti rolling efficiency by arranging front facing seats and when sea condition is soft, we get good view ability by arraging sides facing seats.
Some methods to reduce resistance due to transom sterns have been put into practice. However, the method to eliminate the resistance completely has not been clarified. In this paper, how to design wave-less transom stern form has been investigated based on the results of the authors' studies until now. To verify the clarified design method, model tests have been conducted. Results of the model tests have confirmed: 1) Almost no stern waves are seen behind the designed transom stern at Fr = 0.18 – 0.30. 2) Its resistance is clearly lower than those of conventional transom sterns at the Fr range.
Many attempts have been successfully made for improving propulsive efficiency of ships. Referring to the requirements for the further advances in energy savings in maritime transportation, review was made for the classical concepts of hydrodynamic principles such as Mugnus effect, boundary layer control and etc., and a Column-type Circular Cylinder Propulsion Assistance System is proposed. As a basic study, concept design was made and flow field was surveyed using two dimensional wind tunnel to investigate the possibility of utilizing hydrodynamic lift for ship propulsion assistance. The analysis and feasibility study are presented for the discussion.
Numerical simulation was performed to estimate the general buckling strength and the effective breadth of ring stiffened cylindrical shell under external pressure utilizing FEM. And the simplified formula for general buckling strength of cylindrical shell was derived from FEM result.
This paper describes the unsteady flow around a mechanical pectoral fin. An unsteady, multiblock, overlapping grid Navier-Stokes equation solver is developed to solve this problem. The drag-based swimming mode, which consists of rowing, flapping, and feathering motions, was selected as the fin motion. The unsteady flow past the fin body model that has same motions was computed and compared with the experiments of the mechanical pectoral fin. The numerical time-averaged and time-varied hydrodynamic forces are in good agreement with the measured data.
In this study, the 2 models which have decks at water tight compaerment as Large Passenger Ship (110,000 gross tonnage) were developed, and the damaged ship's behaviors in intermediate stages of flooding were experimentally investigated. In some cases, large heel angle were measured for both models. However, the time to reach to the maximam heel angle for these ships have significantly differens from the safety point of view. It was confirmed that the difference is caused by the difference of flooding verocity from damaged opeing affected by the size of the opening and air compression in compertments.
To reduce CO2 and NOx emission which affects earth environment and energy consumption during transportation, modal shift that means from trucks to rail and marine transportation shows a tendency to increase. According to the change of the diffusion situation of the vehicle exhaust emission by the modal shift, the influence of the carcinogen included in the emission changes too. In this research, it was tried to evaluate how the carcinogens risk to residents in a relatively wide area changed and moreover the effectiveness of the evaluation method for the risk assessment was shown.