A Method to Estimate Internal Fluid Pressure in Tanks during Ballast Water Exchange at Sea

摘要

This paper introduces a method to assess the fluid pressure loads inship's ballast tanks during ballast water exchange at sea. Twodimensionalproblem of sloshing in rectangular tanks with time varyingwater level is investigated by using modal analysis technique, whichhas been widely used to solve the general structural vibration problems.Since the method is based on a linear theory, computational simulationof fluid motion can be performed efficiently for whole duration ofballast exchange which typically takes a few hours for each tankdepending on the size of the tank and the pump capability. A focus ofthis study is on the possibility of a resonance of the fluid motion withina limited duration when the level of ballast water gradually changes andthe natural frequency may pass through the dominant excitingfrequency of ship motions in a stochastic seaway.