Introduction of the open-source boundary element method solver hams to the ocean renewable energy community

A floating offshore renewable energy (ORE) device, such as an offshore wind turbine or wave energy converter, often consists of a floating foundation anchored by a mooring system. Wave interactions with the substructure are essential to its survivability and performance. In the recent decade, an open-source numerical solver HAMS has been developed based on the potential flow theory in analyzing wave-interactions with a three-dimensional arbitrarily-shaped floating or submerged body. The hybrid source-dipole boundary integral equation provides a high degree of accuracy. The so-called irregular frequencies are removed by applying the least-squares method, avoiding the additional numerical work in resolving the wave potentials on the water-plane cross-section. The lower–upper (LU) decomposition method is then used to solve the complex linear algebraic system. Planes of symmetry and parallelism techniques are employed to speed up the computation. Wave diffraction forces, radiation hydrodynamic coefficients and response amplitude operators (RAOs) are evaluated after the wave potentials are obtained. The freesurface elevation and the wave pressure field are also available at the users’ choice. A numerical benchmark of the DeepCwind semisubmersible platform is supplied for illustration of using the solver.