Experimental and numerical investigation on the hydrodynamic forces on a net panel in irregular waves

Accurately predicting the hydrodynamic response of nets subjected to irregular waves continues to be a significant issue because traditional methods do not adequately include the statistical characteristics of irregular waves and the effects of multi-hydrodynamic factors. This study systematically investigated the hydrodynamic interactions between irregular waves and net panels using integrated experimental and numerical approaches. Statistical regression analysis was conducted to assess the effects of the significant wave height H1/3, significant wave period TH1/3, and net solidity Sn on the hydrodynamic responses. The results indicated that the significant wave height had a greater influence on the force magnitude than the significant wave period. Normalization using the product of Reynolds number (Re) and Keulegan–Carpenter number can enhance the linearity of force prediction compared to single-dimensionless parameters. Correlation and significance analyses identified five critical dimensionless parameters governing the hydrodynamic coefficients. Predictive hydrodynamic models of the nets were developed using an artificial neural network (ANN) and nonlinear regression, with the ANN demonstrating superior accuracy. A non-hydrostatic porous-media model was employed to simulate irregular wave–net interactions and was validated against physical experiments through a comparative analysis of the effective wave forces and force spectra. Out-of-sample testing confirmed the robustness of both the predictive models, although the ANN predictions exhibited enhanced reliability at longer effective wavelengths.