Abstract
It is presented how to analyze the wave power absorbed in irregular waves by using both its spectrum and its probability. Absorbed wave power in irregular waves consists of steady component and fluctuations. Both the former and the spectrum of the latter and further the probability density function are derived from a wave spectrum, a transfer function of the motion and characteristics of a load system for general cases in which the load system includes not only damping component (“resistance”) but also spring component (“reactance”) in reaction torque. Comparisons of experiments with the theories about a Salters Duck confirm the utility of this analysis. This analysis can be applied to other floating type wave energy absorbers besides a Salters Duck. It is also presented that an accumulator of a hydraulic device of a load system works very effectively for smoothing the fluctuations of absorbed wave power in irregular waves.
