Experimental and numerical comparisons of self-reacting point absorber wave energy converters in regular waves

•Two self-reacting point absorber WEC designs are compared in regular waves.•1:25 scale physical models of the WECs with feedback controlled PTOs are developed.•Budal׳s upper bound on power capture for one body WECs is extended to two body WECs.•A frequency domain model is validated by power capture and dynamic motion in heave.•The effects of motion constraints and reactive control are investigated.

An experimental and numerical comparison of the performance of two self-reacting point absorber wave energy converter designs is undertaken for heave motions. The designs are either currently, or have recently been, under development for commercialization. The experiments consist of a series of 1:25 scale model tests. The physical model features a re-configurable reacting body shape, a feedback controlled power take-off, and a heave motion constraint apparatus. Detailed descriptions of the reconfigurable model design, the analysis/test methodologies, and power capture are given. An extension of Budal׳s theoretical upper bound on power capture for application to self-reacting point absorbers is proposed. A quantitative comparison is made of the two self-reacting point absorber designs in terms of displacement, power take-off force requirements, and power capture in typical (non-extreme) operating conditions with reference to theoretical upper bounds. The design implications of a reactive power take-off control scheme and relative motion constraints on the wave energy converters are investigated using an experimentally validated numerical dynamics model.