Model Test of a Novel Floating Vertical-Axis Wind Turbine Under Wind and Wave Joint Loads

Abstract Recently a floating vertical-axis wind turbine (VAWT) concept that integrates a VAWT with a steel fishing cage has been developed by leading authors. In order to fathom the kinetic characteristics and performance of this floater under wind and wave joint loads, a series of model tests have been carried out in the ocean basin located at Tsinghua Shenzhen International Graduate School. The wind generation system of this facility allows turbulent wind to be produced such that examination of wind-wave joint actions can be extended to a number of stochastic scenarios. With a scale of 1/40th, the physical models of the floating VAWT and the platform of a steel fishing cage are introduced first. Details are also given to instrumentations and measurement methods. Then, thrust-wind speed tests, free-decay tests, and basin wind-wave tests are respectively carried out to probe the primary dynamic performance of the floating system. The second-order hydrodynamic effects are observed in tests, but they play a secondary role in the response of VAWTs as compared to aerodynamic effects. The aerodynamic loads can induce the obvious low-frequency response at surge and pitch eigen-frequencies, while for heave motion response its contribution is smaller. Additionally, test results reveal that third-per-revolution (3P) effects are insignificant in the platform’s surge, pitch and heave dynamic responses.