Hydrodynamic and aeration characteristics of an aerator of a surging water tank with a vertical baffle under a horizontal sinusoidal motion

To address the hypoxia problem in seawater, this paper proposes an aerator for a surging water tank with a vertical baffle and experimentally and numerically investigates its hydrodynamic and aeration characteristics under a horizontal sinusoidal motion. The intrinsic relationships of the dimensionless maximum wave surface run-up, maximum air pressure, and airflow rate are examined with the ratios of tank surging amplitude to still water depth, tank surging frequency to natural frequency, water exchange height to still water depth, and air hole area to plan area of the sub-tank, respectively. In particular, the dimensionless maximum wave surface run-up reaches its peak when the tank surging frequency fe approaches the natural frequency f1 of the individual sub-tank sloshing mode, and the maximum dimensionless airflow rate appears when the tank surging frequency fe approaches the natural frequency fs of the U-tube sloshing mode. The ratio of the tank surging amplitude to the still water depth and fe/fs play minor roles in the dimensionless maximum air pressure. Furthermore, two methods are used to deduce the prediction formulas for the dimensionless airflow rate. The symbolic regression method performs better than the multivariate non-linear regression method.