Fluid-Oscillation Coupled Analysis for HAWT Rotor Blade

Since large-scale commercial wind turbine generator systems such as MW-class wind turbine are becoming widely operated, the vibration and distortion of the blade are becoming larger and larger. Therefore the soft structure design instead of the solid-design is one of the important concepts to reduce the structural load and the cost of the wind turbine rotor. The objectives of the study are development of the fluid-structure coupled analysis code and evaluation of the soft rotor-blade design to reduce the unsteady aerodynamic blade load. In this paper, fluid-structure coupled analysis for the HAWT rotor blade is performed by free wake panel method coupled with hinge-spring blade model for the Hap wise blade motion. The calculation results are evaluated by comparison with the database of the ^4REL unsteady aerodynamic experiment. In the analysis the unsteady flapwise bending moment in yawed inflow conditions is compared for different blade frequencies.