*Editorial* **Ship Dynamics and Hydrodynamics**

**Serge Sutulo and C. Guedes Soares \***

Centre for Marine Technology and Ocean Engineering (CENTEC), Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal

**\*** Correspondence: c.guedes.soares@centec.tecnico.ulisboa.pt

### **1. Introduction**

Ship hydrodynamics and dynamics is a rather old, traditional branch of applied mechanics and also of naval architecture. Typically, methods and theories developed in the former are applied to the latter aiming at the development of more advanced and efficient ships, and other marine vehicles and ocean structures.

The long development of ship hydrodynamics over many decades has crystallised in the following traditional scientific disciplines: resistance, propulsion, seakeeping, and manoeuvrability. However, in the earlier stages of the development of the naval architecture, the focus was on the properties of a displacement ship, such as its floatability, static stability, and unsinkability. All these properties have been analysed in ship hydrostatics and although the mentioned properties are fundamental, ship hydrostatics has lately been provided with no attention, presuming that all hydrostatic problems are solvable with relatively small efforts and that the corresponding computations are performed routinely. However, this is not true for the remaining disciplines listed above: those which are constantly and intensely developed exploiting multiple theoretical, numerical, and experimental approaches inspired by fluid mechanics, nonlinear dynamics, theory of oscillations, data analysis, control theory, and many other areas.

The present Special Issue contains 17 articles, 1 of which deals with some specific applications of ship hydrostatics to risk analysis, 3 papers belong to the area of ship resistance, 4 revolve around ship propulsion, 5 papers cover the various aspects of seakeeping, and 4 articles are rather dedicated to ship manoeuvrability. However, as can be seen from the more detailed review that follows in the next section, some papers are interdisciplinary, and the above classification is approximate. It is also worthwhile to note that 9 papers out of 17 extensively use methods and codes belonging to computational fluid dynamics (CFD).
