Nonlinear liquid oscillation in a cylindrical tank with an eccentric core barrel

The nonlinear liquid motion in a partially filled cylindrical tank with an eccentric core barrel 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 Galerkinʹs method to the basic equations. The admissible functions of the velocity potential and liquid surface displacement are assumed to be represented by combining the modal functions obtained by the linearized analysis. The effects of the eccentricity of core barrel 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.