Showing papers on "Added mass published in 1968"
TL;DR: In this article, a finite element method was used to obtain the approximate solution of the Laplace's differential equation with any arbitrary boundary condition, and the effects on the inertia coefficients of the restricted water and of the bilgekeel were shown numerically.
Abstract: The added virtual mass and the added virtual mass moment of inertia induced by the vibration of a ship are defined as the equivalent mass and the equivalent mass moment of inertia deduced from the effects of water surrounding a vibrating ship. These equivalent mass and the equivalent mass moment of inertia can be estimated either from the inertia force (or moment) concept or from the kinetic energy concept as long as the ideal fluid is concerned, and the solution of the Laplace's differential equation is required in both cases.This paper, dealing with the problem by the use of the inertia force (or moment) concept, shows that the so-called “finite element method” can be applied, with the aid of a high speed digital computer, to obtain the approximate solution of the Laplace's differential equation with any arbitrary boundary condition. In order to examine the accuracy of this method, the inertia coefficients Cv, CH and CT of vertical, horizontal and rotational vibrations of bars of circular and rectangular cross section are computed first by this method. Then, as an application of this method, the effects on the inertia coefficients of the restricted water and of the bilgekeel are shown numerically.
6 citations
TL;DR: In this paper, the added mass of a moving cylindrical body due to the acceleration of the surrounding fluid was evaluated theoretically by determining the kinetic energy of the fluid surrounding the body, and experimentally by measuring the applied force and resulting acceleration.
Abstract: The added mass of a moving cylindrical body due to the acceleration of the surrounding fluid may be evaluated theoretically by determining the kinetic energy of the fluid surrounding the body, and experimentally by measuring the applied force and resulting acceleration of the body. A theoretical and experimental determination of the added mass for a triangular cylinder is presented. The theoretical analysis is based on the kinetic energy method and neglects any real fluid effects. The theoretical added mass coefficient is computed as 1.53 whereas the experiment gives a value of 1.57. A comparison is made with the corresponding values for cylinders of different cross sections. A short discussion on whether or not viscosity and wall effects were of such magnitude to invalidate the experimental values is also presented.
3 citations