High-Resolution CFD Analysis of Confined Hydrodynamic Flow Through Irregular Underwater Channels

This study presents a high-resolution computational fluid dynamics (CFD) analysis of limited hydrodynamic flow via irregular underwater channels, with an emphasis on pressure redistribution, velocity patterns, and sediment deformation under various flow circumstances. COMSOL Multiphysics was used to generate a highly resolved finite-element mesh that accurately depicts the complexity of the sediment-channel system in terms of shape and impact on water flow. The pressure contour analysis reveals that channel asymmetry generates distinct high- and low-pressure zones, resulting in flow routes that follow Darcy flow behaviour. Simulations of velocity magnitude reveal distinct gradients around channel constrictions, with peak velocities increasing by 25-30% in locations where the geometry becomes tighter. Comparative velocity profiles for different flow states (fs = 0 and fs=1) show changes of up to 15%, demonstrating the sensitivity of confined underwater flow to boundary and forcing conditions. Vertical sediment displacement results indicate localized deformation reactions, with settlement magnitudes on the order of 10−4m, indicating the mechanical impact of hydrodynamic stress. The combined CFD results demonstrate how flow forcing, sediment heterogeneity, and geometric defects all interact to influence how underground channels behave. This work presents a comprehensive characterization framework for forecasting confined hydrodynamics in underwater settings, laying the groundwork for future research that incorporates sediment transport, multiphase interactions, and machine-learning-based flow surrogates to improve predictive accuracy.