Wind Turbine Design Using A Free-wake Vortex Method With Winglet Application

Open Access
Maniaci, David Charles
Graduate Program:
Aerospace Engineering
Doctor of Philosophy
Document Type:
Date of Defense:
September 14, 2012
Committee Members:
  • Mark David Maughmer, Dissertation Advisor
  • Mark David Maughmer, Committee Chair
  • Barnes Warnock Mccormick Jr., Committee Member
  • Dennis K Mc Laughlin, Committee Member
  • Kenneth Steven Brentner, Committee Member
  • Sue Ellen Haupt, Committee Member
  • Sven Schmitz, Committee Member
  • Wind turbine
  • winglet
  • free-wake
  • vortex method
  • rotor aerodynamics
  • blade design
Wind turbine blades are traditionally designed with blade element momentum theory (BEMT). This method is incapable of accurately analyzing non-conventional or non-planar blade planforms. Modern wind turbine blade design thus requires non-standard modeling that can effectively analyze the effects of a non-planar blade, such as a blade with a winglet. The free-wake, distributed vorticity element (FW-DVE) method meets these analysis goals. Previous work applied the FW-DVE method to wind turbines, but did not include the influence of profile forces and did not include any design applications. The present research focused on developing the FW-DVE method into a design tool for wind turbine design applications and on the validation of this tool. In the research presented in this thesis, the FW-DVE method was modified to include the effect of airfoil profile drag and to account for the effects of stall and a non-linear lift-curve. A design tool was created to aid in using the WindDVE analysis code for trade space exploration. The method was used to analyze and design a winglet for a small-scale wind turbine, which was tested in a wind tunnel at the University of Waterloo where it exhibited a 9% increase in the maximum coefficient of power of the rotor. The performance results from this test have been used to validate the FW-DVE method for wind turbine design, along with an analysis of the National Renewable Energy Laboratory’s Unsteady Aerodynamics Experiment Phase VI wind turbine.