The authors present a decision path which allowed them to design successfully a small diffuser augmented wind turbine (DAWT). Multiple methods were applied to design and verify the construction, ranging from an application of simple analytical methods through complex numerical simulations, to finish with the experimental tests of models in different scales. An influence of the turbine duct (diffuser) made it impossible to use standard methods of turbine design and forced one to combine analytical methods with CFD predictions of the flow. A set of different numerical models was used, ranging from the 2D CFDADM up to 3D FRM, which took the most important elements of the final construction into account. Those simulations provided data on aerodynamic loads, further used to verify the design with analytical methods. Some trials of the load analysis employing the FSI were carried out. They proved to be useful for the design load analysis. However, significant requirements of computer resources for simulations of the complex turbine model as well as high deformations of polyamide blades limited the practical application of that method within the project so far. Nevertheless, continuous progress in the computer performance and numerical methods, combining the fluid flow and structural solvers, should provide tools for detailed design analysis in the near future. At the same time, the Fourier transform analysis can be performed on the rotor power signal to provide the fault tolerance and to increase the turbine load factor. Combined with the high frequency measurement of wind velocity, a link between dangerous loading due to environmental conditions and the resulting rotor power fluctuations can be established early enough. In this case, a potential fault could be avoided, thus keeping the turbine uptime to its maximum.

Chapter Contents:

• 3.1 Introduction
• 3.2 SWT design and development
• 3.2.1 Analytical methods
• 3.2.2 BET–CFD coupling
• 3.2.3 Numerical methods for the WT development
• 3.2.4 CFD simulations of the WT
• 3.2.5 BET–CFD simulations of the turbine model in scale
• 3.3 Experimental tools for the small wind turbine load analysis
• 3.4 Analytical methods for estimation of aeromechanical rotor loads
• 3.5 Summary
• Nomenclature
• References

Inspec keywords: wind turbines; design engineering; blades; aerodynamics; mechanical stability

Other keywords: wind velocity; decision path; aerodynamic loads; fluid flow; rotor power signal; small wind turbine load analysis; designing process; 2D CFDADM; STOW project; 3D FRM; fault tolerance; structural solvers; numerical simulations; turbine duct; polyamide blades deformation; Fourier transform analysis; design quality; small diffuser augmented wind turbine; analytical methods

Subjects: Fluid mechanics and aerodynamics (mechanical engineering); Wind power plants; Buckling and instability (mechanical engineering); Power and plant engineering (mechanical engineering); Project and design engineering; Design; Mechanical components