Coupling of two absorbing boundary conditions for 2D time-domain simulations of free surface gravity waves (Q1917115)

The proposed strategy is based on the coupling of two previously known boundary conditions in order to benefit from their different, and complementary, bandwidth: the numerical ``beach'', very efficient in the high frequency range; and a piston-like Neumann condition, asymptotically ideal for low frequencies. The coupling method gives excellent results in the whole range of frequencies of interest and is as easy to implement in nonlinear as in linear versions. One of its major advantages is that it does not require any spectral knowledge of the incident waves.