Coupled Vibroacoustic Modelling of Surface and Underwater Vehicles

Physical Foundations, Multiphysics Prediction, and Validation Aspects of Underwater Radiated Noise

Abstract

The prediction of underwater radiated noise (URN) is of strategic importance both in military
applications and in the protection of the marine environment. Based on the scientific literature
and current standardisation practice, URN cannot be interpreted as a purely hydrodynamic
phenomenon. Instead, excitation mechanisms, structural vibrations, and hydrodynamic loading
jointly determine the far-field sound pressure level through a coupled vibroacoustic multiphysics
system. This review discusses the relevant physical foundations of underwater sound propagation,
the principal source mechanisms of URN (propeller cavitation, structure-borne noise, and flowinduced
noise), and the associated coupled modelling approaches, including structural finite
element modelling, fluid–structure interaction, CFD-based flow modelling, acoustic analogy
methods, and FEM–BEM coupling. Furthermore, the hierarchy of predictive models and the tradeoff
between computational cost and predictive accuracy are examined. As a central element,
a detailed vibroacoustic multiphysics workflow suitable for URN prediction is presented, together
with a discussion of validation strategies and the uncertainties of sea trial measurements in the
context of the ISO 17208 standard series.