Experimental validation on the dynamic response of a novel floater uniting a vertical-axis wind turbine with a steel fishing cage

A floating vertical-axis wind turbine (VAWT) concept that combines a VAWT with a steel fishing cage has been proposed by lead authors. To probe kinetic characteristics of this floater, this study performs a series of model tests at a 1/40 scale. The comprehensive calibration tests, including wind/wave field quality validation tests, hammer tests, quasi-static mooring tests, and decay tests, are performed for various identification purposes. After that a series of basin tests for the floater under regular waves, irregular waves, and irregular waves with steady/turbulent wind are performed. The experimental data of motions and loads are compared with numerical predictions from an in-house fully coupled simulation tool. Good agreements are observed, affirming the accuracy of the developed simulation tool. Because the main dimension of cage coincides with wavelength and , multi-peaks appear in surge and pitch spectra in the wave frequency band (0.3–1.3 rad/s). The second-order wave effects are clearly observed in tests, but they induce a much smaller low-frequency motion response (<0.3 rad/s) than that by aerodynamic effects. The mooring tension response is influenced by surge motions more than by first-order wave actions. Third-per-revolution (3P) effects are dominant in tower-top shear forces but insignificant to the platform motions.