MCIVER, M., 1992. Second-order oscillatory forces on a body in waves. Applied Ocean Research, 14 (6), pp.325-331.
When a small amplitude, water-wave tram is incident upon a fixed body, a
second-order analysis predicts that the body experiences a steady force and a
force at twice the frequency of the incident wave The double-frequency force is
comprised of integrals of products of linear quantities over the surface of the body
and the mean waterline and a term due to the second-order potential An
application of Green's theorem to the first-order potential and its horizontal
derivative shows that the integral of the first order terms over the body is related
in a simple way to the waterline integral and the far-field representation of the
linear, diffraction potential A minor modification of the analysis yields the farfield
formulae for the drift force.