A study of the effects of initial circulation upon elliptic vortex-ring behavior
Visualization and analysis of Particle Image Velocimetry measurement data sets were carried out to inspect the vortex dynamic of vortex-ring produced by (a) nozzle’s aspect ratio=1, 2, 3, 4 (b) Reynolds number=500, 1000, 2000, 4000 and (c) stroke-ratio =1.5, 3.0. Vorticity maps, vortex core traje...
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| Other Authors: | |
| Format: | Final Year Project (FYP) |
| Language: | English |
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Nanyang Technological University
2021
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/150704 |
| _version_ | 1826129345389789184 |
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| author | Pu, Wen Wei |
| author2 | New Tze How, Daniel |
| author_facet | New Tze How, Daniel Pu, Wen Wei |
| author_sort | Pu, Wen Wei |
| collection | NTU |
| description | Visualization and analysis of Particle Image Velocimetry measurement data sets were
carried out to inspect the vortex dynamic of vortex-ring produced by (a) nozzle’s aspect
ratio=1, 2, 3, 4 (b) Reynolds number=500, 1000, 2000, 4000 and (c) stroke-ratio =1.5,
3.0. Vorticity maps, vortex core trajectory and associated phenomenon, particularly axis-switching
rate was examined in the study to establish the effects of different initial
circulation conditions upon vortex behaviours such as fluid entrainment to enhance jet
mixing. The results show that the axis-switching rate rises to a critical aspect ratio of
AR=2 and drops subsequently. The increase in Reynolds number imposes less distinct but
positive influence on axis-switching rate while lower stroke-ratio increases the total
number of axis-switching due to its stable trajectory. Besides, the formation of trailing
jet discovered at L/d=3.0 with elliptic nozzle indicates that aspect ratio affects formation
number. Vortex reconnection is only observed at a high aspect ratio and Reynolds number
tells that both initial conditions are essential in controlling vortex deformation. Other
observations such as the formation of secondary vortices, leapfrogging, vortex stretching
and bifurcation are found to be in good agreement with the past studies. |
| first_indexed | 2024-10-01T07:39:03Z |
| format | Final Year Project (FYP) |
| id | ntu-10356/150704 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T07:39:03Z |
| publishDate | 2021 |
| publisher | Nanyang Technological University |
| record_format | dspace |
| spelling | ntu-10356/1507042021-05-30T06:19:45Z A study of the effects of initial circulation upon elliptic vortex-ring behavior Pu, Wen Wei New Tze How, Daniel School of Mechanical and Aerospace Engineering DTHNEW@ntu.edu.sg Engineering::Aeronautical engineering::Aerodynamics Visualization and analysis of Particle Image Velocimetry measurement data sets were carried out to inspect the vortex dynamic of vortex-ring produced by (a) nozzle’s aspect ratio=1, 2, 3, 4 (b) Reynolds number=500, 1000, 2000, 4000 and (c) stroke-ratio =1.5, 3.0. Vorticity maps, vortex core trajectory and associated phenomenon, particularly axis-switching rate was examined in the study to establish the effects of different initial circulation conditions upon vortex behaviours such as fluid entrainment to enhance jet mixing. The results show that the axis-switching rate rises to a critical aspect ratio of AR=2 and drops subsequently. The increase in Reynolds number imposes less distinct but positive influence on axis-switching rate while lower stroke-ratio increases the total number of axis-switching due to its stable trajectory. Besides, the formation of trailing jet discovered at L/d=3.0 with elliptic nozzle indicates that aspect ratio affects formation number. Vortex reconnection is only observed at a high aspect ratio and Reynolds number tells that both initial conditions are essential in controlling vortex deformation. Other observations such as the formation of secondary vortices, leapfrogging, vortex stretching and bifurcation are found to be in good agreement with the past studies. Bachelor of Engineering (Aerospace Engineering) 2021-05-29T06:46:49Z 2021-05-29T06:46:49Z 2021 Final Year Project (FYP) Pu, W. W. (2021). A study of the effects of initial circulation upon elliptic vortex-ring behavior. Final Year Project (FYP), Nanyang Technological University, Singapore. https://hdl.handle.net/10356/150704 https://hdl.handle.net/10356/150704 en application/pdf Nanyang Technological University |
| spellingShingle | Engineering::Aeronautical engineering::Aerodynamics Pu, Wen Wei A study of the effects of initial circulation upon elliptic vortex-ring behavior |
| title | A study of the effects of initial circulation upon elliptic vortex-ring behavior |
| title_full | A study of the effects of initial circulation upon elliptic vortex-ring behavior |
| title_fullStr | A study of the effects of initial circulation upon elliptic vortex-ring behavior |
| title_full_unstemmed | A study of the effects of initial circulation upon elliptic vortex-ring behavior |
| title_short | A study of the effects of initial circulation upon elliptic vortex-ring behavior |
| title_sort | study of the effects of initial circulation upon elliptic vortex ring behavior |
| topic | Engineering::Aeronautical engineering::Aerodynamics |
| url | https://hdl.handle.net/10356/150704 |
| work_keys_str_mv | AT puwenwei astudyoftheeffectsofinitialcirculationuponellipticvortexringbehavior AT puwenwei studyoftheeffectsofinitialcirculationuponellipticvortexringbehavior |