Evolution of three-dimensional unsteady wave modulations
نویسنده
چکیده
A numerical investigation of nonlinear interaction mechanisms producing large wave energy concentrations, which lead to episodic transient waves, is performed using both a Higher Order Spectral (HOS) model and a three-dimensional (3D) fully nonlinear Numerical Wave Tank (NWT). Self-focusing of wave energy is achieved through modulating a periodic wave train along two orthogonal directions. Nonlinear unsteady 3D wave groups are obtained, which show a curved wavefront structure, with focusing of wave energy in both the directional and the frequency domains. Breaking would ultimately occur in such groups. This, however, cannot be described by the HOS model but, based on the HOS solution, both breaking and non-breaking freak waves may be simulated in the NWT, and their shape and kinematics can be studied.
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