Wind Turbine Trailing-Edge Aerodynamic Brake Design

This report describes the design of a centrifugally actuated aerodynamic-overspeed device for a horizontal-axis wind turbine. The device will meet the following criteria: (1) It will be effective for airfoil angles of attack 0 degrees to 45 degrees, (2) it will be stowed inside the blade profile prior to deployment, (3) it will be capable of offsetting the positive torque produced by the overallblade, (4) hinge moments will be minimized to lower actuator loads and cost, and (5) it will be evaluated as a potential power modulating active rotor-control system. A literature review of aerodynamic braking devices was conducted. Information from the literature review was used to conceptualize the most effective devices for subsequent testing and design. Wind-tunnel test data for severalbraking devices are presented in this report. Using the data for the most promising configuration, a preliminary design was developed for a MICON 65/13 wind turbine with Phoenix 7 .9-m rotor blades.