Effect of Shallow Water on the Added Mass for the Vertical Hull Vibration of Ships : Analytical Calculation Using the Singularity Distribution Method

Abstract

In this paper, the effect of shallow water on the two-dimensional added mass coefficient C_v and the three-dimensional correction factor J_v for the vertical hull vibration of the ships are investigateg. For this purpose, the numerical calculations using the singularity distribution method as well as the model experiments for the mathematical models have been carried out by changing the water depth. From this study, it is shown that the comparison between the results of the calculations and the model experiments gives a fairly good agreement. And it is also found that the shallow water has a considerable effect on the two-dimensional added mass coefficient C_v, while it has a negligibly small effect on the three-dimensional correction factor J_v. In the last part of this paper, the two-dimensional added mass coefficient C_v obtained from the numerical calculations for the vertical vibration of the body with the various sectional shapes are presented in the chart form and it will be used for an easy estimation of the added mass in the shallow water at the initial design stage of the ships.