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Effects of non-sinusoidal pitching motion on the propulsion performance of an oscillating foil

Numerical simulations have been used in this paper to study the propulsion device of a wave glider based on an oscillating hydrofoil, in which the profile of the pitching and heaving motion have been prescribed for the sake of simplicity. A grid model for a two-dimensional NACA0012 hydrofoil was bui...

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Detalles Bibliográficos
Autores principales: Qi, Zhanfeng, Zhai, Jingsheng, Li, Guofu, Peng, Jiazhong
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6602205/
https://www.ncbi.nlm.nih.gov/pubmed/31260479
http://dx.doi.org/10.1371/journal.pone.0218832
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author Qi, Zhanfeng
Zhai, Jingsheng
Li, Guofu
Peng, Jiazhong
author_facet Qi, Zhanfeng
Zhai, Jingsheng
Li, Guofu
Peng, Jiazhong
author_sort Qi, Zhanfeng
collection PubMed
description Numerical simulations have been used in this paper to study the propulsion device of a wave glider based on an oscillating hydrofoil, in which the profile of the pitching and heaving motion have been prescribed for the sake of simplicity. A grid model for a two-dimensional NACA0012 hydrofoil was built by using the dynamic and moving mesh technology of the Computational Fluid Dynamics (CFD) software FLUENT and the corresponding mathematical model has also been established. First, for the sinusoidal pitching, the effects of the pitching amplitude and the reduced frequency were investigated. As the reduced frequency increased, both the mean output power coefficient and the optimal pitching amplitude increased. Then non-sinusoidal pitching was studied, with a gradual change from a sinusoid to a square wave as the value of β was increased from 1. It was found that when the pitching amplitude was small, the trapezoidal pitching profile could indeed improve the mean output power coefficient of the flapping foil. However, when the pitching amplitude was larger than the optimal value, the non-sinusoidal pitching motion negatively contributed to the propulsion performance. Finally, the overall results suggested that a trapezoidal-like pitching profile was effective for the oscillating foil of a wave glider when the pitching amplitude was less than the optimal value.
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spelling pubmed-66022052019-07-12 Effects of non-sinusoidal pitching motion on the propulsion performance of an oscillating foil Qi, Zhanfeng Zhai, Jingsheng Li, Guofu Peng, Jiazhong PLoS One Research Article Numerical simulations have been used in this paper to study the propulsion device of a wave glider based on an oscillating hydrofoil, in which the profile of the pitching and heaving motion have been prescribed for the sake of simplicity. A grid model for a two-dimensional NACA0012 hydrofoil was built by using the dynamic and moving mesh technology of the Computational Fluid Dynamics (CFD) software FLUENT and the corresponding mathematical model has also been established. First, for the sinusoidal pitching, the effects of the pitching amplitude and the reduced frequency were investigated. As the reduced frequency increased, both the mean output power coefficient and the optimal pitching amplitude increased. Then non-sinusoidal pitching was studied, with a gradual change from a sinusoid to a square wave as the value of β was increased from 1. It was found that when the pitching amplitude was small, the trapezoidal pitching profile could indeed improve the mean output power coefficient of the flapping foil. However, when the pitching amplitude was larger than the optimal value, the non-sinusoidal pitching motion negatively contributed to the propulsion performance. Finally, the overall results suggested that a trapezoidal-like pitching profile was effective for the oscillating foil of a wave glider when the pitching amplitude was less than the optimal value. Public Library of Science 2019-07-01 /pmc/articles/PMC6602205/ /pubmed/31260479 http://dx.doi.org/10.1371/journal.pone.0218832 Text en © 2019 Qi et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Qi, Zhanfeng
Zhai, Jingsheng
Li, Guofu
Peng, Jiazhong
Effects of non-sinusoidal pitching motion on the propulsion performance of an oscillating foil
title Effects of non-sinusoidal pitching motion on the propulsion performance of an oscillating foil
title_full Effects of non-sinusoidal pitching motion on the propulsion performance of an oscillating foil
title_fullStr Effects of non-sinusoidal pitching motion on the propulsion performance of an oscillating foil
title_full_unstemmed Effects of non-sinusoidal pitching motion on the propulsion performance of an oscillating foil
title_short Effects of non-sinusoidal pitching motion on the propulsion performance of an oscillating foil
title_sort effects of non-sinusoidal pitching motion on the propulsion performance of an oscillating foil
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6602205/
https://www.ncbi.nlm.nih.gov/pubmed/31260479
http://dx.doi.org/10.1371/journal.pone.0218832
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