Abstract
Hydrodynamic loading of solid bodies like ships or breakwaters can be simulated well using geometry resolving computational fluid dynamics methods, where the body shape is resolved in the mesh describing the domain. Slender bodies, like spars, multiple tidal turbine blades or lattice structures would often require prohibitively high cell counts, since the geometrical features to be resolve are much smaller than the overall domain. However, such bodies are usually made up of generic cross sections like round, square or standardised technical profiles like the famous NACA 4/5 digit series for which good parametrisations of reaction forces to incoming flow exist. Actuator line methods thus apply inflow dependent reaction forces to the fluid domain, allowing the computationally efficient simulation of slender bodies and have been used extensively, for example for wake assessments or tidal turbine array simulations. Slender bodies are also standard building blocks of structural simulations using the finite element method. Combining actuator line theory with a finite element beam model allows to efficiently simulate flexible structures, like tidal turbine blades or nettings used in fish farms. This paper presents an implementation of such a coupled model in OpenFOAM. The underlying numerical method is detailed and first example application and validation cases are provided.