Self-similarity of the near-field turbidity current propagation in deep-sea mining
Phys. Rev. Fluids 10, 074303 – Published 24 July, 2025
DOI: https://doi.org/10.1103/125j-72lp
Abstract
In deep-sea mining operations, the discharge of sediment plumes significantly impacts the ocean environment, thus necessitating precise evaluation. In this work, we conduct large-eddy simulations to investigate sediment transport in deep-sea mining, focusing on the influence of the vehicle wake and various control parameters, including vehicle speed, discharge rate, and vehicle elevation relative to the seafloor, on the evolution of turbidity current. Our simulation demonstrates that the interaction between turbidity current and vehicle's downstream vortical wake strongly affects the distribution of fluid kinetic energy and sediment concentration. The vehicle wake enhances the sediment diffusion and reduces the descending velocity of the current downstream, resulting in a larger region of sediment contamination. We find that the current propagation in the streamwise direction can be approximately predicted by the axisymmetric box model, while the propagation in the lateral direction is characterized by the two-dimensional box model. Depending on the ratio of vehicle velocity to discharge velocity, the propagation of turbidity current transitions from a constant-rate influx to a fixed-volume influx. In statistically stationary states, both the mean and standard deviation of concentration fields exhibit self-similar behavior with respect to the streamwise location and control parameters. Additionally, by comparing seafloor wall shear stress across different simulations, we provide guidance for mitigating unfavorable operating conditions in deep-sea mining activities. These results, which provide important information for modeling the far-field sediment dispersion, are crucial for accurately assessing the large-scale environmental impact of deep-sea mining.
