Long-term two-dimensional analysis of the flow field around a hovering flapping flat-plate wing
A flapping wing is considered as one of the most effective aerodynamic systems for micro air vehicles (MAVs). Many numerical studies have been attempted to investigate the flow field around a flapping wing; nevertheless, the long-term flow characteristics, which can cause a non-negligible effect on...
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| Format: | Article |
| Language: | English |
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The Japan Society of Mechanical Engineers
2023-06-01
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| Series: | Journal of Fluid Science and Technology |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/jfst/18/2/18_2023jfst0026/_pdf/-char/en |
| _version_ | 1797733911472635904 |
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| author | Tomoki YAMAZAKI Yoshiaki ABE Tomonaga OKABE |
| author_facet | Tomoki YAMAZAKI Yoshiaki ABE Tomonaga OKABE |
| author_sort | Tomoki YAMAZAKI |
| collection | DOAJ |
| description | A flapping wing is considered as one of the most effective aerodynamic systems for micro air vehicles (MAVs). Many numerical studies have been attempted to investigate the flow field around a flapping wing; nevertheless, the long-term flow characteristics, which can cause a non-negligible effect on long-term hovering operations of MAVs have not been adequately clarified owing to the high computational cost involved. This study numerically investigates the long-term flow characteristics around a flapping flat-plate wing during hovering flight at a chord-based Reynolds number of 2.5 × 104. Based on the finite-volume method with the arbitrary Lagrangian-Eulerian (ALE) method, two-dimensional laminar flow analyses were performed for 40 periods of flapping motions with stroke inversion angles of β = 30°, 45°, and 60°. The results showed that the lift coefficient CL was not completely periodic despite the periodic motion. To identify the CL characteristics for each β case, a half-stroke-period-based phase-average of CL was calculated over different time segments. Then, the phase-averaged CL using the fifth to 30th periods sufficiently provided converged aerodynamic characteristics: the β = 30° and 45° cases had a single peak of CL, whilst the β = 60° had double peaks; the second peak taking the maximum CL in the β = 60° case was delayed compared to others. The results of this study provide a guideline for the number of periods required in the numerical estimation of the CL characteristics and associated flow fields around flapping-type MAVs, which contributes to their further improvement of them. |
| first_indexed | 2024-03-12T12:36:31Z |
| format | Article |
| id | doaj.art-ab5b683c997041d6a35c133c501a1aa2 |
| institution | Directory Open Access Journal |
| issn | 1880-5558 |
| language | English |
| last_indexed | 2024-03-12T12:36:31Z |
| publishDate | 2023-06-01 |
| publisher | The Japan Society of Mechanical Engineers |
| record_format | Article |
| series | Journal of Fluid Science and Technology |
| spelling | doaj.art-ab5b683c997041d6a35c133c501a1aa22023-08-29T02:31:50ZengThe Japan Society of Mechanical EngineersJournal of Fluid Science and Technology1880-55582023-06-01182JFST0026JFST002610.1299/jfst.2023jfst0026jfstLong-term two-dimensional analysis of the flow field around a hovering flapping flat-plate wingTomoki YAMAZAKI0Yoshiaki ABE1Tomonaga OKABE2Institute of Fluid Science, Tohoku UniversityInstitute of Fluid Science, Tohoku UniversityGraduate School of Engineering, Tohoku UniversityA flapping wing is considered as one of the most effective aerodynamic systems for micro air vehicles (MAVs). Many numerical studies have been attempted to investigate the flow field around a flapping wing; nevertheless, the long-term flow characteristics, which can cause a non-negligible effect on long-term hovering operations of MAVs have not been adequately clarified owing to the high computational cost involved. This study numerically investigates the long-term flow characteristics around a flapping flat-plate wing during hovering flight at a chord-based Reynolds number of 2.5 × 104. Based on the finite-volume method with the arbitrary Lagrangian-Eulerian (ALE) method, two-dimensional laminar flow analyses were performed for 40 periods of flapping motions with stroke inversion angles of β = 30°, 45°, and 60°. The results showed that the lift coefficient CL was not completely periodic despite the periodic motion. To identify the CL characteristics for each β case, a half-stroke-period-based phase-average of CL was calculated over different time segments. Then, the phase-averaged CL using the fifth to 30th periods sufficiently provided converged aerodynamic characteristics: the β = 30° and 45° cases had a single peak of CL, whilst the β = 60° had double peaks; the second peak taking the maximum CL in the β = 60° case was delayed compared to others. The results of this study provide a guideline for the number of periods required in the numerical estimation of the CL characteristics and associated flow fields around flapping-type MAVs, which contributes to their further improvement of them.https://www.jstage.jst.go.jp/article/jfst/18/2/18_2023jfst0026/_pdf/-char/enmicro air vehicleflapping winghovering flightunsteady flowcomputational fluid dynamics |
| spellingShingle | Tomoki YAMAZAKI Yoshiaki ABE Tomonaga OKABE Long-term two-dimensional analysis of the flow field around a hovering flapping flat-plate wing Journal of Fluid Science and Technology micro air vehicle flapping wing hovering flight unsteady flow computational fluid dynamics |
| title | Long-term two-dimensional analysis of the flow field around a hovering flapping flat-plate wing |
| title_full | Long-term two-dimensional analysis of the flow field around a hovering flapping flat-plate wing |
| title_fullStr | Long-term two-dimensional analysis of the flow field around a hovering flapping flat-plate wing |
| title_full_unstemmed | Long-term two-dimensional analysis of the flow field around a hovering flapping flat-plate wing |
| title_short | Long-term two-dimensional analysis of the flow field around a hovering flapping flat-plate wing |
| title_sort | long term two dimensional analysis of the flow field around a hovering flapping flat plate wing |
| topic | micro air vehicle flapping wing hovering flight unsteady flow computational fluid dynamics |
| url | https://www.jstage.jst.go.jp/article/jfst/18/2/18_2023jfst0026/_pdf/-char/en |
| work_keys_str_mv | AT tomokiyamazaki longtermtwodimensionalanalysisoftheflowfieldaroundahoveringflappingflatplatewing AT yoshiakiabe longtermtwodimensionalanalysisoftheflowfieldaroundahoveringflappingflatplatewing AT tomonagaokabe longtermtwodimensionalanalysisoftheflowfieldaroundahoveringflappingflatplatewing |