An equivalent mechanical model for fluid sloshing in a rigid cylindrical tank equipped with a rigid annular baffle

A mass-spring mechanical model for linear sloshing of fluid in a rigid cylindrical tank with a rigid annual baffle is developed. By means of the subdomain method, the complicated fluid domain is divided into several subdomains with pure boundary conditions and interface conditions. Combined with the continuity conditions of velocity and pressure on interfaces, the velocity potential of fluid in each subdomain is analytically solved. The mass-spring model for fluid sloshing is established by generating the same hydrodynamic shear force and overturning moment as those from the exact solutions when the tank is subjected to horizontal excitations. The present model gives all the mechanical parameters including the convective mass-spring oscillators and the impulsive mass as well as their positions. Comparative studies between the present solutions and the available results verify the correctness of the mechanical model. Based on the normalized equivalent masses and spring stiffnesses, the dynamic responses of fluid in tanks are discussed with respect to the fluid height, the baffle position and the inner radius of the baffle, respectively. The present model is especially suitable for dealing with complicated liquid-structure systems. The motivation and novelty of this study are confirmed by an application of the present model to a multi-tank system.