Numerical modeling of natural vibrations of coaxial shells partially filled with fluid, taking into account the effects on the free surface

This work is devoted to the numerical analysis of vertical elastic coaxial cylindrical shells completely or partially filled with a quiescent compressible fluid account for sloshing its free surface. The problem solved in axisymmetric formulation using semi-analytical version finite element method. medium described by wave equation, which together conditions prescribed at boundaries reduced weak form Bubnov - Galerkin A mathematical dynamic thin-walled structures developed variational principle virtual displacements and linear theory thin based on Kirchhoff Love hypotheses. pressure walls structure calculated according Bernoulli's equation. Sloshing modes caused gravitational effects surface liquid are excluded from resulting system equations through use iteration condensation model has been verified comparing it known data case single shell fluid. influence level lowest natural frequencies vibrations different variants kinematic boundary (rigid clamping both edges, cantilever support) widths annular gap between them evaluated. It found that examined configurations, channel stronger frequency spectrum compared cavity inner due fact vibration change wider range.