Abstract Slosh dynamics of liquid filled tanks is of paramount importance in the study of fluid-structure interaction. Since beginning sectors and compartments are used in fuel tanks of rockets and massive sea ferrying liquid carriers to control dynamic properties of liquid filled tanks. Compartmentalization is also considered essential to control yaw and pitching of sea vessels by controlling bilge water level. However, Solid partition walls are subjected to considerably high hydrodynamic loads and require increased thickness of material thereby causes increased cost and weight. Perforation is one of the methods for reducing ill effects of compartmentalization. Perforation reduces pressure drop across the baffle which in turn reduces required structural strength of the baffle. Screens with optimum perforation placed appropriately may ensure greater dynamic stability without reduction in damping. Screens are widely used as damping devices in TLD in structural engineering, as Propellant Management and Acquisition Devices (PMAD) in aerospace engineering. Several experimental and theoretical studies are carried out to analyze the effects of surface-piercing and bottom-mounted vertical baffles, screens but no well-established numerical method is developed so far. In this paper a finite element method using pressure formulation is adopted to study dynamic properties of rectangular rigid containers with single-slotted internal elements and screens