Date of Award

Winter 12-15-2015

Author's School

School of Engineering & Applied Science

Author's Department

Mechanical Engineering & Materials Science

Degree Name

Master of Science (MS)

Degree Type

Thesis

Abstract

This focus of this research is on the study of the aerodynamic performance of a Looped Airfoil Wind Turbine (LAWT™) using the Computational Fluid Dynamics (CFD) software. The looped airfoil wind turbine (LAWT™) is a patented new technology by EverLift Wind Technology, Inc. for generating power from wind. It takes advantage of the superior lift force of a linearly traveling wing compared to the rotating blades in conventional wind turbine configurations. Compared to horizontal and vertical axis wind turbines, the LAWT™ can be manufactured with minimal cost because it does not require complex gear systems and its blades have a constant profile along their length. These considerations make the LAWT™ economically attractive for small-scale decentralized power generation in rural areas. Each LAWT™ is estimated to generate power in the range of 10 kW to 1 MW. Due to various advantages, it is meaningful to determine the maximum possible power generation of a LAWT™ by optimizing its structural layout.

In this study, CFD simulations were conducted using ANSYS Fluent to determine the total lift and drag coefficient of a cascade of airfoils. The adaptive structured meshes were created using the commercial mesh generating software ICEM. The k-kl-ω turbulence model was used to account for flow in the laminar-turbulent transition region. Given the lift and drag coefficients and the kinematics of the system, an analytical formula for the power generation of the LAWT™ was developed. General formulas were obtained for the average lift and drag coefficients so that the total power could be predicted for any number of airfoils in LAWT™. The spacing between airfoils and the track angle were identified as the key design parameter that affected the power generation of the viii LAWT™. The results showed that a marked increase in total power could be achieved if the optimum spacing between the airfoils was used for a given track angle. The same idea was then applied to study an analogous floating Looped Airfoil Hydro-Turbine (LAHT) which converts the kinetic energy of river streams into electricity. The results showed that each LAHT of the same configuration as LAWT can generate nearly 756% more power than the power generated by the LAWT due to much higher density of water compared to air. Finally, to generate more power from LAWT and LAHT, a new highly-cambered airfoil was studied to generate more lift and drag to generate more power. Thus various parameters of LAWT and LAHT were optimized for generating optimum power.

Language

English (en)

Chair

Ramesh K. Agarwal

Comments

Permanent URL: https://doi.org/10.7936/K7HT2MK0

Included in

Engineering Commons

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