Predicting ship waves in sheltered waterways – An application of XBeach to the Stockholm Archipelago, Sweden

Abstract Predicting hydrodynamic forces from ship waves along a waterway is essential for managing a sustainable shoreline in fairways. In this context, a numerical model can be a useful tool for calculating ship waves in fairways with complex geometry. XBeach is a numerical model offering the potential to be a one-tool solution for simulating ship waves from the ship to the shore. However, XBeach has not been evaluated against field measurements of ship waves. Thus, the objective of this paper is (1) to compare XBeach against high-quality field measurements of ship waves and (2) to assess its general applicability to ship wave simulations through an extensive sensitivity analysis with regard to the main input parameters. Water level measurements from 42 passages of the M/S Baltic Princess in the Furusund navigational fairway in the Stockholm Archipelago were chosen to test and evaluate XBeach. The results showed that XBeach was able to generate and propagate the primary and secondary waves. Primary waves were reproduced well with a mean absolute error (MAE) of 3 cm for the drawdown height. The overall secondary wave field pattern was represented by XBeach; however, for the largest, single divergent wave comparison for height, period, and timing showed deviation from the observations. Overall, XBeach was found to be a robust model for ship wave applications, only requiring input data typically available. Sensitivity analysis for a generic hull, derived from the type of vessel studied and with the corresponding dimensions as the real hull, showed similar results enabling robust and reliable simulations without access to detailed technical drawings.