Coupled computational fluid dynamics/multibody dynamics method with application to wind turbine simulations

Li, Yuwei. "Coupled computational fluid dynamics/multibody dynamics method with application to wind turbine simulations." PhD ii To my family iii ACKNOWLEDGMENTS I would like to express my greatest appreciation to my advisor, Associate Professor Pablo M. Carrica, who has been continuously supporting me throughout my Ph.D. research with his knowledge, experience, enthusiasm and patience. I am grateful to him for his time, instrumental discussions and critique. Without his guidance and persistent help this thesis would not have been possible. I would also like to thank my committee members for their time and help, Professors P. Another thank-you goes to my fellow students in IIHR-Hydroscience & Engineering, who had shared their precious time with me. I am grateful to have my beloved fiancée Dan to accompany me, who makes my life meaningful and wonderful. I am indebted to my parents for their love and support for everything I do. Offshore Wind Turbines Including Wave loads and Motions ". iv ABSTRACT A high fidelity approach coupling the computational fluid dynamics method (CFD) and multi-body dynamics method (MBD) is presented for aero-servo-elastic wind turbine simulations. The approach uses the incompressible CFD dynamic overset code CFDShip-Iowa v4.5 to compute the aerodynamics, coupled with the MBD code Virtual.Lab Motion to predict the motion responses to the aerodynamic loads. The IEC 61400-1 ed. 3 recommended Mann wind turbulence model was implemented in this thesis into the code CFDShip-Iowa v4.5 as boundary and initial conditions, and used as the explicit wind turbulence for CFD simulations. A drivetrain model with control systems was implemented in the CFD/MBD framework for investigation of drivetrain dynamics. The tool and methodology developed in this thesis are unique, being the first time with complete wind turbine simulations including CFD of the rotor/tower aerodynamics, elastic blades, gearbox dynamics and feedback control systems in turbulent winds. Dynamic overset CFD simulations were performed with the benchmark experiment UAE phase VI to demonstrate capabilities of the code for wind turbine aerodynamics. The complete turbine geometry was modeled, including blades and approximate geometries for hub, nacelle and tower. Unsteady Reynolds-Averaged Navier-Stokes (URANS) and Detached Eddy Simulation (DES) turbulence models were used in the simulations. Results for both variable wind speed at constant blade pitch angle and variable blade pitch angle at fixed wind speed show that the CFD predictions match the experimental data consistently well, including the general trends for power and thrust, sectional normal force coefficients and …