FloatLab: Design and testing of a 5x5m² wind generator for FOWT lab scale testing

A 5x5 array of 1m² individual controlled blower units are designed and stacked to form a wind generator of 25m² as part of the Danish FloatLab project, targeting lab scale testing of FOWT in a combined wind and wave environment. The final lab setup will feature a wave basin (25x30m² and 3m deep) with 3D waves, a wind-wall and a 1:70 scale model turbine of the 22MW IEA reference turbine. The setup aims at true Froude scaling of wind and waves in dynamic load testing of integrated floater and turbine models in controlled conditions. The 5x5 array setup with individual control, allows for onset of large-scale atmospheric turbulence, 70x70m² in full scale. The first 1m² blower unit has been built and tested statically and with dynamic loading. The complete array is currently in preparation with an expected run-in during March-April 2025, initially a reduced size 2x2 and thereafter the full array. The design top-speed is 5m/s and TI~2-4%. Measurements on the first blower unit shows that static requirements are well achieved and testing under harmonic rpm variation, high level of turbulence TI~50% is attainable at rated speed (~1.5m/s) at frequencies as high as ½Hz, which is well within the target for the Froude scaled turbine. Additional measured data will be reported on for the reduced and full-size array.