Vertical-Axis Wind Turbine Steady and Unsteady Aerodynamics for Curved Deforming Blades

Journal Article · 12 August 2021 · AIAA Journal

DOI: https://doi.org/10.2514/1.j060476 · OSTI ID:1817721

Moore, Kevin R. ^[1]; Ennis, Brandon L. ^[1]

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1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Vertical-axis wind turbines’ simpler design and low center of gravity make them ideal for floating wind applications. However, efficient design optimization of floating systems requires fast and accurate models. Low-fidelity vertical-axis turbine aerodynamic models, including double multiple streamtube and actuator cylinder theory, were created during the 1980s. Commercial development of vertical-axis turbines all but ceased in the 1990s until around 2010 when interest resurged for floating applications. Despite the age of these models, the original assumptions (2-D, rigid, steady, straight bladed) have not been revisited in full. When the current low-fidelity formulations are applied to modern turbines in the unsteady domain, aerodynamic load errors nearing 50% are found, consistent with prior literature. However, a set of steady and unsteady modifications that remove the majority of error is identified, limiting it near 5%. This paper shows how to reformulate the steady models to allow for unsteady inputs including turbulence, deforming blades, and variable rotational speed. A new unsteady approximation that increases numerical speed by 5–10× is also presented. Combined, these modifications enable full-turbine unsteady simulations with accuracy comparable to higher-fidelity vortex methods, but over 5000× faster.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE Advanced Research Projects Agency - Energy (ARPA-E)
• Grant/Contract Number: NA0003525
• OSTI ID: 1817721
• Report Number(s): SAND--2021-9945J; 697992
• Journal Information: AIAA Journal, Journal Name: AIAA Journal Journal Issue: 1 Vol. 60; ISSN 0001-1452
• Publisher: AIAACopyright Statement
• Country of Publication: United States
• Language: English