Some aspects of the French flexible bag wave-energy device

French (1977) has suggested a channel form wave energy absorber in which power is removed from the wave front by flexible bags along the channel walls. He has given a simple theoretical model for such a device which has, however, several drawbacks which we attempt to remedy. Several two-dimensional models of the channel are examined in which one or more of the dimensions are many wavelengths long. In particular, it is possible to apply realistic boundary conditions at the channel walls and obtain relationships between the wall stiffness $\mu$ and the decay rate of the wave front, $\sigma$. Two main methods are used; the variational method developed by Evans and Morris (1972) and the Wiener-Hopf method, as modified by Jones (1952).