Towards a Framework for Aero-elastic Multidisciplinary Design Optimization of Horizontal Axis Wind Turbines

Multi-disciplinary Design Optimization (MDO) has been successfully applied in the aerospace industry, so given the similarities to wind turbine design, the application of MDO techniques is a potential opportunity to improve wind turbine design. MDO attempts to solve for optimal design parameters by considering the performance of multiple disciplines simultaneously. This approach differs from sequential optimization in which each discipline is optimized separately. Evaluating the design with a comprehensive approach leads to better balanced designs. This article presents a Multi-Disciplinary Feasible (MDF) framework that incorporates an aerodynamics code based on vortex methods with a nonlinear beam formulation for the blade aerodynamics and structural dynamics, in order to eventually study non-straight blades with arbitrary composite layups. In the current work, the framework is exercised to optimize a conventional design for a 100 m blade. It was found that obtaining accurate coupled gradients for a fully-relaxed wake simulation using explicit aerodynamic solution methods is very challenging. A rigid wake approach enabled more reliable convergence, and suggestions are given for future work in applying MDO to this class of wind turbine analysis methods.