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Author ORCID Identifier

https://orcid.org/0000-0003-2916-9793

Document Type

Open Access Dissertation

Degree Name

Doctor of Philosophy (PhD)

Degree Program

Mechanical Engineering

Year Degree Awarded

2020

Month Degree Awarded

February

First Advisor

Dr. J. Blair Perot

Second Advisor

Dr. Matthew Lackner

Subject Categories

Aerodynamics and Fluid Mechanics

Abstract

As a result of insects or other environmental fouling, surface roughness on wind turbine blades can reduce power output significantly. Superhydrophobic surfaces, though possibly a passive, cost-saving, answer to the problem of ice accretion on wind turbine rotors in cold climates, may alter turbulence development in the blade boundary layer similar to environmental roughness. This work uses an equivalent sand grain extension to the Turbulent Potential model to computationally assess the aerodynamic effects of surface roughness on the s809 airfoil, including a representational superhydrophobic surface. Rough surface boundary layer theory, application of the equivalent sand grain method, roughness parameter correlation, and wind turbine aerodynamic computational approaches are discussed. Modifications to the Turbulent Potential model including turbulence Reynolds number dependence are addressed. An altered version of the Turbulent Potential model is proposed using an elliptic damping equation in the pressure strain term. Validation of Turbulent Potential model changes is demonstrated by comparison to multiple direct numerical simulations of Moser et al., the impinging jet of Cooper et. al, and the Ohio State University wind tunnel experiments of the s809 airfoil with both a smooth and rough leading edge.

DOI

https://doi.org/10.7275/ygbv-kv28

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

Available for download on Saturday, August 01, 2020

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