Modeling the Temporal Response of a Microtab in an Aeroelastic Model of a Wind Turbine

CFD (Computational Fluid Dynamics) analysis of the temporal response of the microtab show that it has two disadvantages compared with a trailing edge flap, when considering it for active load control of a wind turbine. First of all the microtab has a reverse control phenomenon in the initial phase of deployment, and second of all the response is delayed, compared with the flap, due to buildup of flow structures. This motivated us to find an engineering model for the temporal response of the microtab to investigate the behavior of the microtab in an aeroelastic model of a wind turbine. Before we attempted to model the microtab in detail, we inserted temporal response of the microtab found with CFD directly into the aeroelastic code FLEX5. We found that the reverse control was not important for the response of the blade. We propose to use a simple queue delay to model the flow physics of the microtab. Finally, we calculated the load reduction potential of the microtab, assuming that we could model it as a delay, and compared it to that of a trailing edge flap. In our calculation the trailing edge flap had a load reduction potential twice as big as the microtab solution on the UPWIND reference turbine.