CFD-Based Analysis of Circular Variable-Pitch Vertical Axis Hydrokinetic Turbines in Riverine Environments

Author

• Gavin R. Nowack, University of Arkansas, FayettevilleFollow

Date of Graduation

5-2026

Document Type

Thesis

Degree Name

Bachelor of Science in Mechanical Engineering

Degree Level

Undergraduate

Department

Mechanical Engineering

Advisor/Mentor

Dr. Keith Walters

Committee Member

Dr. Keith Walters

Second Committee Member

Dr. Jim Leylek

Abstract

In Stuart Fletcher's paper on Comparative Analysis of Circular Variable-Pitch Vertical Axis Hydrokinetic Turbines Through CFD-Based Efficiency Mapping [1], three design types of hydrokinetic turbines were analyzed. This paper is an extension of his works, exploring the option of placing variable pitch hydrokinetic turbines into the more realistic environment of a river. This concept aims to utilize the velocity profile of a river to reduce the opposing flow on the bottom of the hydrofoil when it is rotating against the current. The configuration considered was a perfectly flat riverbed as proof of the concept, with further intent on exploring more realistic scenarios in the future. It was found that the flat riverbed option, although minimal, did provide an increase in efficiency return for the Wollongong type but reduction in efficiency for the circular OFEH and Darrieus types. Further investigations will need to be undertaken to explore how other hydrofoil types and configurations would react to this environment, as well as to compare the calculated results to physical testing.

Keywords

Computational Fluid Dynamics; Wollongong Turbine; Oscillating Energy Foil Harvister; Darrieus Turbine; Prescribed Turbulen Inflow; Minimum Grid Cell Size Estimation

Citation

Nowack, G. R. (2026). CFD-Based Analysis of Circular Variable-Pitch Vertical Axis Hydrokinetic Turbines in Riverine Environments. Mechanical Engineering Undergraduate Honors Theses Retrieved from https://scholarworks.uark.edu/meeguht/153