Numerical simulations and modeling of turbidity currents from a moving source

We present numerical simulations of turbidity currents generated by a moving source as a model of particle clouds released by underwater vehicles such as those used in deep-sea dredging and mining. We use two approaches to model the flow and resulting deposits. First, we adapt the shallow-water equations to include a moving source of both momentum and particles. Second, we modify the classical box model to include a moving source. The most important governing dimensionless parameters are a Froude number, Fr, based on the depth of sediments being resuspended and the dimensionless settling speed of those sediments, u_s. We find that Fr is most determinant in the current and deposit shape, with Fr>2 resulting in elongated shapes and Fr<2 resulting in rounder ones, and that u_s determines the rate at which deposits grow. Overall, both models found similar trends, but the box model, while much less computationally expensive, was less accurate when spatial non-uniformities developed, as happens at long times.