Research on data analysis method of oscillating water column wave energy converters

Abstract

Abstract Taking the floating oscillating water column central tube wave energy converters (OWC WECs) as the research goal, the Fourier transform (FFT), and the ensemble empirical mode decomposition method (EEMD) were used to statistically analyze the wave height, motion acceleration, velocity and displacement of the device in the physical model test from the perspective of a frequency domain. Through the Fourier transform, the energy spectrum of the incident wave and the motion of the WEC is obtained, and it is found that the peak frequency of the two is the same, that is, the period is 1.138s, but the peak energy of the former is slightly greater than that of the latter. Through the ensemble empirical mode decomposition method, the 1-8 intrinsic mode functions of the incident wave and the displacement of the device are obtained, which shows that the device efficiently captures the dominant frequency wave in the incident wave, that is, the wave height is 0.0628m, the period is 1.1s, and the motion displacement of the vertical direction obtained by the device is 0.0585mm, and the period is 1.1119s. At the same time, it absorbs low-frequency, long-period reflected waves in the pool. The analysis results of the two methods are highly consistent, and the OWC WEC shows good hydrodynamic performance, with efficient wave trapping ability and fast wave responsability. This paper’s research methods and results provide a basis for the later optimization of the device and a new idea for the data processing method of the WECs.