Nonlinear Liquid Oscillation in an Annular Cylindrical Tank Subjected to Pitching Excitation

Abstract

Nonlinear liquid motion in a partially filled annular cylindrical tank, in response to a pitching excitation, is investigated. The nonlinearity of the liquid surface oscillation is considered in the response analysis of the sloshing motion. Basic equations are derived by employing the variational principle. The nonlinear ordinary differential equations governing the liquid surface oscillation are then derived by applying Galerkin's method to the basic equations. The effects of the ratio of inner radius to outer one on liquid surface oscillation are discussed. The time histories of the liquid surface displacement are calculated to the harmonic pitching excitations. An experiment was conducted using a model tank. A good agreement was found between the theoretical and experimental results. It is shown that the nonlinear analysis is important for estimating the sloshing responses.