Fast accurate computation of the fully nonlinear solitary surface gravity waves

• Highly accurate computation of solitary waves in the full Euler equations.
• Derivation of the Babenko equation in the conformally mapped domain.
• The proposed algorithm is very fast due to the extensive use of the FFT operation.
• The solution can be theoretically obtained to the arbitrary high accuracy.

In this short note, we present an easy to implement and fast algorithm for the computation of the steady solitary gravity wave solution of the free surface Euler equations in irrotational motion. First, the problem is reformulated in a fixed domain using the conformal mapping technique. Second, the problem is reduced to a single equation for the free surface. Third, this equation is solved using Petviashvili’s iterations together with pseudo-spectral discretisation. This method has a super-linear complexity, since the most demanding operations can be performed using a FFT algorithm. Moreover, when this algorithm is combined with the multi-precision floating point computations, the results can be obtained to any arbitrary accuracy.