Parallel pulsed jets for precise underwater propulsion
Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.
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| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2016
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| Online Access: | http://hdl.handle.net/1721.1/103430 |
| _version_ | 1826196994201223168 |
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| author | Athanassiadis, Athanasios G |
| author2 | Douglas P. Hart. |
| author_facet | Douglas P. Hart. Athanassiadis, Athanasios G |
| author_sort | Athanassiadis, Athanasios G |
| collection | MIT |
| description | Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016. |
| first_indexed | 2024-09-23T10:40:46Z |
| format | Thesis |
| id | mit-1721.1/103430 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T10:40:46Z |
| publishDate | 2016 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/1034302019-04-10T22:47:02Z Parallel pulsed jets for precise underwater propulsion Athanassiadis, Athanasios G Douglas P. Hart. Massachusetts Institute of Technology. Department of Mechanical Engineering. Massachusetts Institute of Technology. Department of Mechanical Engineering. Mechanical Engineering. Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016. This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. Cataloged from student-submitted PDF version of thesis. Includes bibliographical references (pages 95-98). A significant limitation for underwater robots is their ability to maneuver in tight spaces or for complex tracking tasks. Next generation vehicles require thrusters that can overcome this problem and efficiently provide high maneuverability at low speeds. Recently, thruster design has begun to draw inspiration from nature's swimmers, applying the principles of pulsed jet propulsion to robotic thrusters. Although most developments have focused on single jet actuators, nature provides some indications that multi-jet systems can provide propulsive benefits -- marine invertebrates called sales connect into chains of individual animals that each eject short jets to collaboratively move the entire chain efficiently around the ocean. However, despite the promise of multi-jet propulsion, there are no existing models or empirical data that explain the physics of multi-jet propulsion. As a result, there are no physically motivated rules to guide the design of man-made multi-jet thrusters. In this thesis, I experimentally investigate how interactions between neighboring jets in a multi-jet thruster will affect the system's propulsive performance. I use high-speed fluorescence imaging to investigate the mutual influence of two pulsed jets under conditions relevant to low-speed maneuvering in a vehicle (Re ~ 350). Using a new force estimation technique developed in this thesis, I analyze the video data to evaluate how thrust and efficiency are affected by the jet spacing. This analysis reveals that, compared to non-interacting jets, the efficiency and thrust generated by the pair of interacting jets can fall by nearly 10% as the jets are brought into close proximity. Based on this data, I develop a model of vortex interactions to explain the thrust and efficiency drop. The data and model described in this thesis contribute new insights to understand vortex formation in pulsed jets, and these results can be used to guide the design of multi-jet underwater propulsion syste by Athanasios G. Athanassiadis. S.M. 2016-07-01T18:23:22Z 2016-07-01T18:23:22Z 2016 2016 Thesis http://hdl.handle.net/1721.1/103430 952332338 eng CD-ROM contains 8 files in .mov format. 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 98 pages application/pdf Massachusetts Institute of Technology |
| spellingShingle | Mechanical Engineering. Athanassiadis, Athanasios G Parallel pulsed jets for precise underwater propulsion |
| title | Parallel pulsed jets for precise underwater propulsion |
| title_full | Parallel pulsed jets for precise underwater propulsion |
| title_fullStr | Parallel pulsed jets for precise underwater propulsion |
| title_full_unstemmed | Parallel pulsed jets for precise underwater propulsion |
| title_short | Parallel pulsed jets for precise underwater propulsion |
| title_sort | parallel pulsed jets for precise underwater propulsion |
| topic | Mechanical Engineering. |
| url | http://hdl.handle.net/1721.1/103430 |
| work_keys_str_mv | AT athanassiadisathanasiosg parallelpulsedjetsforpreciseunderwaterpropulsion |