Experimental and numerical investigation of a bottom-fixed net cage under regular waves

In this paper, the experimental and numerical simulation of a bottom-fixed cage equipped with double-layer nets is carried out to analyse the wave field characteristics under regular waves. The accuracy of the numerical method is rigorously validated by comparing simulation outcomes with experimental data under identical wave conditions. The effects of wave period, wave height, angle of attack and the absence of net on the wave field of the cage are studied. The results demonstrate that when the wave period is kept constant, the wave transmission coefficient decreases as the wave height increases. In contrast, when the wave height remains unchanged, the transmission coefficient increases as the wave period becomes longer. The change of wave direction from 0° to 22.5° mainly leads to relatively small differences in transmission coefficients inside the net cage. The configuration of a double-layer side net shows better wave attenuation performance than the single-layer side net. With the decrease of the side net layer, the wave transmission coefficient tends to increase gradually. The influence of the bottom net on wave attenuation is relatively insignificant. These conclusions can offer some insights for the structural configuration and hydrodynamic optimisation of aquaculture platforms and cages. • An experimental study and a numerical simulation of a bottom-fixed cage equipped with double-layer nets are conducted. • The accuracy of the numerical simulation method is validated by comparing simulation outcomes with experimental data. • The effects of wave period, height, angle of attack and absence of the net on the wave field around the cage are studied. • The results show that for each wave period, the wave transmission coefficient decreases as the wave height increases. • When the wave height remains unchanged, the transmission coefficient increases as the wave period becomes longer.