This paper investigates berthed ship–passing ship hydrodynamic interactions using unsteady Reynolds-averaged Navier–Stokes (URANS) solver StarCCM+ in both model scale and full scale. A double-body approximation method is adopted to investigate the hydrodynamic effects on the berthed ship when in close proximity with the passing ship. A benchmark experimental test condition is replicated for the verification and validation of the numerical simulation. Based on the validated numerical model, the interaction forces and moments are predicted for different passing ship speeds and lateral separations. The same conditions are repeated in full scale to quantify possible scale effects. The trends seen in the numerical results correlated well with past author's findings. The difference in the model-scale and full-scale interaction force and moment predications are not significant. Full scale berthed ship–passing ship interaction forces and moments can therefore be approximated (for similar cases) by model-scale tests with confidence.

Highlights:

(1) URANS computations are conducted to study berthed ship–passing ship interactions in both full-scale and model-scale conditions.
(2) Numerical results are validated against benchmark experimental data.
(3) Relationship between interaction forces and moments acting on the berthed ship with respect to passing ship speed and lateral separation are identified.
(4) Scale effects in berthed ship–passing ship interaction forces and moments are quantified.