Abstract
A nonlinear theory is developed for a recent wave energy converter design inspired by the mechanics of animal arteries. The device is a long and hollow rubber tube immersed beneath the sea surface. Excited by passing water waves outside, pressure waves are resonated inside the tube and advance toward the stern to spin a turbine for power production. To account for significant magnification, the classical linear theory of blood vessels is modified. Diffraction is neglected but nonlinearity and wall friction are included. The spatial evolution of harmonic amplitudes is shown to be governed by a dynamical system similar to that in nonlinear optics. The maximum available power flux is predicted as a function of the tube length and other structural parameters. It is hoped that the theory may assist further development of the novel device.