Over the years, several approaches have been developed to compute the effect of propeller wash (propwash) linked to a numerical sediment transport model [Wang et al. (2016) and others]. These approaches have limitations that usually prevent full dynamic coupling. Herein, we present the development of a propwash model dynamically linked to the widely used open-source EFDC+ code (Craig, et al., 2020). The model computes shear stresses and scour induced by propwash, including propeller energy on the three-dimensional flow field.

Approach/Activities.
The propwash model itself is based on the approach of Hamill and collaborators (1998, 2011, 2014, 2016). DSI combined the approaches presented in the different papers to formulate a general model of the propwash for a single propeller. To address the effects of multiple propellers, a superposition approach is used. EFDC+ ship track input data was designed to use an automatic identification system (AIS) data, but any ship location data can be used. Any number of vessels can be simulated simultaneously.

The numerical solution approach is based on a propeller diameter scaled sub-grid moving with the ship. At each time step and each sub-grid node, the propwash induced velocity and resulting bed shear stress is computed. Next, sediment erosion is computed and the mass flux of eroded sediment is integrated over the model grid. As a ship passes through the model domain, sediments, and any contaminants associated with those sediments, that are eroded from propwash are mixed into the water column for subsequent advection, diffusion, settling, and redeposition.
The implementation of propwash into EFDC+ is applied to a berthing in the Puget Sound (ferry docking facility in Kingston, WA). The influences and effects of tidal fluctuations concurrent with the ferry arrivals and departures are simulated and compared to the experimental results presented in Kastner et al., 2019.

Application of a Dynamically Coupled Near/Far Field Propeller Wash Scour Sediment Transport Model to Estimate Scour Around a Berthing Facility

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[Paper Proceedings](https://doi.org/10.1061/9780784483466)

Conference DOI: https://doi.org/10.26226/m.6329c39b68fb0e00131f77d2