On a method for simulation-based wind turbine blade design

Wind turbines are an important means for the production of renewable energy. Wind conditions vary from one site to another and the design of a horizontal axis wind turbine depends on these local wind conditions. One of the important aspects of the design of a wind turbine concerns the aerodynamic shape of the rotor blades. The research presented in this thesis focusses on the development of a computational method that can be used for solving aerodynamic shape optimization problems. A gradient-based optimization method is employed for this purpose. For a feasible optimization method, the gradients must be computed efficiently. This goal is achieved using the discrete adjoint equation method, which is independent of the number of design variables. Robust and accurate evaluation of partial derivatives is achieved by means of the dual number method. The flow domain is discretized using composite overset grids and the compressible Euler equations are used to model the flow. The optimization method has been used for the optimization of a swept wing for both sub-critical and transonic flow conditions. The results show that the method is robust and can be used to efficiently solve aerodynamic shape optimization problems. Moreover, using the method for solving aerodynamic shape optimization problems involving a wind turbine rotor blade has been discussed, regarding possible objective functions for the present optimization framework. Some issues arose solving the optimization problem for a wind turbine blade. These issues have been identified and suggestions are put forward for resolving them