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Lift Equivalence and Cancellation for Airfoil Surge-Pitch-Plunge Oscillations

Metadata Updated: January 20, 2025

A NACA 0018 airfoil in freestream velocity is oscillated in longitudinal, transverse, and angle-of-attack directions with respect to the freestream velocity, known as surge, plunge, and pitch. The lift-based equivalence method introduces phase shifts between these three motions to construct in-phase sinusoidal components for maximum lift, waveform construction. Lift cancellation is also determined with the exact negative pitch and plunge motion amplitudes found from the equivalence method to achieve out-of-phase wave destruction. Lift cancellation occurs when a combination of these motions is sought to obtain a constant lift magnitude throughout the oscillation cycle. To achieve both equivalence and cancellation of lift, a prescribed pure pitch amplitude through the Theodorsen theory equates the corresponding equivalent plunge amplitude and pitch-plunge phase shift. These Theodorsen, linear superposition findings of pitch-plunge are leveraged toward the Greenberg theory to determine a closed-form, surge-pitch-plunge solution through the addition of a surge-plunge phase shift and optimal surge amplitude for lift cancellation. The lift cancellation surge-pitch-plunge amplitudes define the equivalence amplitude investigated here and theoretically limit the experiment to combinations of the first lift harmonic of the Greenberg theory. The analytical results are then compared with experimental lift force measurements and dye visualization. The normalized lift differences due to unsteady wake and boundary-layer behavior are examined to explore the extents of the Greenberg theory for these cases of lift-based equivalence and cancellation.

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Public: This dataset is intended for public access and use. License: Creative Commons Attribution

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Dates

Metadata Created Date January 11, 2025
Metadata Updated Date January 20, 2025

Metadata Source

Harvested from OpenEI data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date January 11, 2025
Metadata Updated Date January 20, 2025
Publisher North Carolina State University
Maintainer
Identifier https://data.openei.org/submissions/7988
Data First Published 2020-01-01T07:00:00Z
Data Last Modified 2021-01-14T17:27:40Z
Public Access Level public
Bureau Code 019:20
Metadata Context https://openei.org/data.json
Metadata Catalog ID https://openei.org/data.json
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Data Quality True
Datagov Dedupe Retained 20250120171954
Harvest Object Id a51ab977-75cf-4400-afbb-e862ce4a9511
Harvest Source Id 7cbf9085-0290-4e9f-bec1-91653baeddfd
Harvest Source Title OpenEI data.json
Homepage URL https://mhkdr.openei.org/submissions/348
License https://creativecommons.org/licenses/by/4.0/
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Program Code 019:009
Projectlead Carrie Noonan
Projectnumber EE0008635
Projecttitle Device Design and Robust Periodic Motion Control of an Ocean Kite System for Marine Hydrokinetic Energy Harvesting
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Source Hash 6c62bac2abb1efb3ace45df667b0410b355f7fa6da40b46ecd78b888c317b5bb
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