Performance of biologically inspired flapping foils
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.
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| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2007
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| Online Access: | http://hdl.handle.net/1721.1/35636 |
| _version_ | 1811079970056830976 |
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| author | Read, Melissa B. (Melissa Beth), 1982- |
| author2 | Alexandra H. Techet. |
| author_facet | Alexandra H. Techet. Read, Melissa B. (Melissa Beth), 1982- |
| author_sort | Read, Melissa B. (Melissa Beth), 1982- |
| collection | MIT |
| description | Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006. |
| first_indexed | 2024-09-23T11:23:24Z |
| format | Thesis |
| id | mit-1721.1/35636 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T11:23:24Z |
| publishDate | 2007 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/356362019-04-12T15:41:20Z Performance of biologically inspired flapping foils Read, Melissa B. (Melissa Beth), 1982- Alexandra H. Techet. Massachusetts Institute of Technology. Dept. of Mechanical Engineering. Massachusetts Institute of Technology. Dept. of Mechanical Engineering. Mechanical Engineering. Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006. Includes bibliographical references (p. 133-135). Flapping foil propulsion is thought to provide AUVs with greater maneuverability than propellers. This thesis seeks to simplify the design process for this type of propulsion system by identifying thrust and wake characteristics for flapping foils and determining how these factors scale with certain parameters. First, the wake of a flapping NACA 0030 foil was studied qualitatively using fluorescent dye visualizations. The foil was heaved and pitched in a sinusoidal fashion. The effects of varying Reynolds number, Strouhal number, maximum pitch angle, and the phase shift between heave and pitch were studied. It was determined that at very low Strouhal numbers the wake was 'S' like and at moderate Strouhal numbers the wake contained discreet horseshoe-like vortices. Next, the wake was studied quantitatively using particle image velocimetry (PIV). Through this technique, numerical thrust coefficients and vorticity strengths were obtained as well as qualitative information regarding the morphology of the wake. The coefficient of thrust peaked at a different Strouhal number for each Reynolds number studied. This trend was compared to natural phenomenon. (cont.) Impulsively started maneuvers were also studied using PIV. Both single flaps and half flaps of the foil were studied. It was determined that impulsively started single flaps produced a much larger maximum coefficient of thrust than the impulsively started half flaps. Many of the experiments were repeated using a biologically inspired trout tail shaped foil. by Melissa B. Read. S.M. 2007-01-10T16:53:46Z 2007-01-10T16:53:46Z 2006 2006 Thesis http://hdl.handle.net/1721.1/35636 76701534 eng M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 135 p. 5718806 bytes 5724422 bytes application/pdf application/pdf application/pdf Massachusetts Institute of Technology |
| spellingShingle | Mechanical Engineering. Read, Melissa B. (Melissa Beth), 1982- Performance of biologically inspired flapping foils |
| title | Performance of biologically inspired flapping foils |
| title_full | Performance of biologically inspired flapping foils |
| title_fullStr | Performance of biologically inspired flapping foils |
| title_full_unstemmed | Performance of biologically inspired flapping foils |
| title_short | Performance of biologically inspired flapping foils |
| title_sort | performance of biologically inspired flapping foils |
| topic | Mechanical Engineering. |
| url | http://hdl.handle.net/1721.1/35636 |
| work_keys_str_mv | AT readmelissabmelissabeth1982 performanceofbiologicallyinspiredflappingfoils |