Roll response of ship fitted with passive stabilizing tank

Abstract

Physical and mathematical models of roll motions of a ship equipped with a roll stabilizing tank of working liquid free surface, is presented. Elaboration of the physical model was based on the idea of two mutually coupled mathematical pendulae. On the basis of the physical model, motion equations of the ship with the tank were determined and solved. A way of using the achieved solutions is shown, as well as calculation formulae for coefficients of the motion equations, directly related to the main parameters of the ship and tank, are presented. Such form of the coefficients enhances possiblility of application of the equations and their solutions in ship design practice. Some examples of the use of the solutions for analysis of stabilizing effectiveness of a designed tank for a given ship, are also attached. Moreover, guidelines for correct design of the stabilizing tanks having free surface of liquid, based on the proposed physical model of the ship-tank system, are offerred. It is also indicated that on the basis of the presented results it would be possible to search for ways to make operation of the stabilizing tanks in question more effective.