Numerical Investigation of Focused Waves on Uniform Currents

In this paper, a 2D numerical model for the interaction between focused waves and uniform currents is developed based on the fully nonlinear potential theory. The model is developed by using a time-domain higher-order boundary element method (HOBEM) combined with a mixed Eulerian-Lagrangian technique as a time marching process. The focused wave trains are numerically generated by a piston wavemaker on a uniform current. The proposed model is verified by comparison with the published results on monochromatic wave interaction with a current, bichromatic wave interaction with a current over a plane slope, and pure focused wave groups. The influence of the uniform current on the properties of the focused waves, including the maximum focused wave crest, shift of focal position and focal time, and spectrum bandwidth, is further studied.