Near-field behavior of variable property jet with swirling flow generated by a change in gravitational orientation
This paper presents the near-field behavior of a variable property jet with swirling flow generated by a change in gravitational orientation, focusing on the onset of vortex formation at the jet interface and the subsequent vortex breakdown (VB). Two types of gases are used to create a significant d...
| Main Authors: | , , |
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| Format: | Article |
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American Institute of Physics Inc.
2015
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| Online Access: | http://ir.unimas.my/id/eprint/12729/ |
| _version_ | 1848837262205255680 |
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| author | Adzlan, A. Tsutsumi, S. Gotoda, H. |
| author_facet | Adzlan, A. Tsutsumi, S. Gotoda, H. |
| author_sort | Adzlan, A. |
| building | UNIMAS Institutional Repository |
| collection | Online Access |
| description | This paper presents the near-field behavior of a variable property jet with swirling flow generated by a change in gravitational orientation, focusing on the onset of vortex formation at the jet interface and the subsequent vortex breakdown (VB). Two types of gases are used to create a significant difference in the physical properties between the inner and outer fluids: CO2 with high-density and low-viscosity, and helium with low-density and high-viscosity. We propose a nondimensional instability parameter M* as a useful index for predicting the onset of vortex formation at a swirling jet interface. Inverted gravity (+1g) enlarges the region of unstable VB of the CO2 jet compared with that in normal gravity (-1g), which clearly shows that the buoyancy force has a significant impact on unstable VB. The trends of the changes in the jet half-angle and stagnation point height are investigated in detail for the preceding stable VB. Our physical model derived by considering the momentum balance in a swirling flow is adopted to understand the mechanism of the notable change in the stagnation point height in +1g with increasing swirl number of the inner jet and Reynolds number of the outer jet. |
| first_indexed | 2025-11-15T06:36:52Z |
| format | Article |
| id | unimas-12729 |
| institution | Universiti Malaysia Sarawak |
| institution_category | Local University |
| last_indexed | 2025-11-15T06:36:52Z |
| publishDate | 2015 |
| publisher | American Institute of Physics Inc. |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | unimas-127292017-02-24T01:49:38Z http://ir.unimas.my/id/eprint/12729/ Near-field behavior of variable property jet with swirling flow generated by a change in gravitational orientation Adzlan, A. Tsutsumi, S. Gotoda, H. TJ Mechanical engineering and machinery This paper presents the near-field behavior of a variable property jet with swirling flow generated by a change in gravitational orientation, focusing on the onset of vortex formation at the jet interface and the subsequent vortex breakdown (VB). Two types of gases are used to create a significant difference in the physical properties between the inner and outer fluids: CO2 with high-density and low-viscosity, and helium with low-density and high-viscosity. We propose a nondimensional instability parameter M* as a useful index for predicting the onset of vortex formation at a swirling jet interface. Inverted gravity (+1g) enlarges the region of unstable VB of the CO2 jet compared with that in normal gravity (-1g), which clearly shows that the buoyancy force has a significant impact on unstable VB. The trends of the changes in the jet half-angle and stagnation point height are investigated in detail for the preceding stable VB. Our physical model derived by considering the momentum balance in a swirling flow is adopted to understand the mechanism of the notable change in the stagnation point height in +1g with increasing swirl number of the inner jet and Reynolds number of the outer jet. American Institute of Physics Inc. 2015 Article PeerReviewed Adzlan, A. and Tsutsumi, S. and Gotoda, H. (2015) Near-field behavior of variable property jet with swirling flow generated by a change in gravitational orientation. Physics of Fluids, 27 (2). ISSN 1070-6631 https://www.scopus.com/record/display.uri?eid=2-s2.0-84923845877&origin=inward&txGid=0 DOI: 10.1063/1.4906372 |
| spellingShingle | TJ Mechanical engineering and machinery Adzlan, A. Tsutsumi, S. Gotoda, H. Near-field behavior of variable property jet with swirling flow generated by a change in gravitational orientation |
| title | Near-field behavior of variable property jet with swirling flow generated by a change in gravitational orientation |
| title_full | Near-field behavior of variable property jet with swirling flow generated by a change in gravitational orientation |
| title_fullStr | Near-field behavior of variable property jet with swirling flow generated by a change in gravitational orientation |
| title_full_unstemmed | Near-field behavior of variable property jet with swirling flow generated by a change in gravitational orientation |
| title_short | Near-field behavior of variable property jet with swirling flow generated by a change in gravitational orientation |
| title_sort | near-field behavior of variable property jet with swirling flow generated by a change in gravitational orientation |
| topic | TJ Mechanical engineering and machinery |
| url | http://ir.unimas.my/id/eprint/12729/ http://ir.unimas.my/id/eprint/12729/ http://ir.unimas.my/id/eprint/12729/ |