Two-dimensional viscous numerical simulation of liquid sloshing in rectangular tank with/without baffles and comparison with potential flow solutions

A viscous fluid model based on non-inertial reference system is developed for the problem of liquid sloshing in rectangular tank with/without baffles. The accuracy of the numerical model is validated against available theoretical solutions, experimental data and numerical predictions by linear and nonlinear potential flow models and different Navier-Stokes solvers. The numerical examinations indicate that the dissipative effects have significant influence on the sloshing responses in both non-baffled and baffled tanks. The sloshing responses that are associated with the natural frequencies can be finally damped out due to the physical dissipations, while they are entirely retained in the potential solutions, which accounts for the general over-predictions of sloshing amplitudes by the potential flow theory. The sloshing in baffled tank involves more dissipation due to the stronger vortical flow. The resonant frequency and amplitude are highly dependent on the baffle width and position. The relative sloshing amplitudes around the resonant condition are found to decrease with the excitation amplitude in a power law. The necessity of using viscous fluid model for sloshing predictions is addressed. The extremely long numerical computations have to be carried out in order to obtain convincing stable solutions, especially for the weakly damped sloshing motion.