Towards Efficient Fluid-Structure-Control Interaction for Smart Rotors

One of the solutions to speed up the energy transition is the smart rotor concept: wind turbine blades with actively controlled Trailing Edge Flaps. In the past decade feasibility studies (both numerical and experimental) have been performed to assess the applicability of smart rotors in future design strategies and the next step is the development and use of high-fidelity models for further analysis of the concept. This thesis studies two issues within high fidelity modeling of smart rotors: 1) Computational Fluid Dynamics based Fluid-Structure Interaction models are computationally expensive and efforts should be focused on making them more efficient and 2) how well is a high fidelity model able to predict smart rotors/airfoils compared to experimental data and engineering models? To increase the efficiency consistent time integration for fluid-structure interaction on collocated grids for incompressible flows is derived and shown. Secondly, Radial Basis Function mesh deformation is further developed into an adaptive, automated, efficient and robust mesh deformation method no longer requiring detailed a priori knowledge of the structural deformation. Finally, the increase in confidence/insight in the CFD based models is achieved by means of validation of unsteady flap aerodynamics and performing aero-servo-elastic simulations of an airfoil with flap in gusty conditions using both CFD and a dynamic stall based unsteady aerodynamic model. Both the time integration method as well as the RBF method, are ready for large scale (3D) problems and thus for application within the FSCI model of a smart rotor. With the validation study and the direct comparison of the aero-servo-elastic response to a gust, first steps are made to increase the confidence of the method, or at least to quantify its accuracy compared to experiments and an engineering model.