Experimental Investigation on Jet Vector Deflection Jumping Phenomenon of Coanda Effect Nozzle
The Coanda effect nozzle is a fluid thrust vectoring technology that uses the Coanda effect to control jet vector deflection. The jumping phenomenon often occurs in the process of controlling jet vector deflection. This phenomenon leads to the nonlinearity of thrust vector control. It destroys the c...
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| Format: | Article |
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MDPI AG
2022-07-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/12/15/7567 |
| _version_ | 1797414633160572928 |
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| author | Shaoqing Chi Yunsong Gu |
| author_facet | Shaoqing Chi Yunsong Gu |
| author_sort | Shaoqing Chi |
| collection | DOAJ |
| description | The Coanda effect nozzle is a fluid thrust vectoring technology that uses the Coanda effect to control jet vector deflection. The jumping phenomenon often occurs in the process of controlling jet vector deflection. This phenomenon leads to the nonlinearity of thrust vector control. It destroys the control performance of the aircraft and brings potential dangers to the safety of the aircraft. The jumping phenomenon occurs in an unsteady flow field different from the traditional flow phenomenon. The flow structure in an unsteady flow field changes with time, so it is not easy to control by the traditional active flow control method. This paper explains the reasons for the jumping phenomenon from two aspects: flow field stability and flow structure. Secondly, the unsteady flow field with the jumping phenomenon is studied and analyzed by a flow visualization experiment and dynamic force measurement. Furthermore, the dynamic modal decomposition (DMD) method is used to extract the characteristic frequencies of the critical vortices causing jets to jump in unsteady flow fields. Finally, a pulsed jet with the same characteristic frequency is used to control the varying vortices in the unsteady flow field. The experimental results show that the active flow control method, which extracts the characteristic frequency of the critical flow field structure by DMD, effectively suppresses the jumping phenomenon in the unsteady flow field. It also linearizes the process of jet nonlinear vector deflection. |
| first_indexed | 2024-03-09T05:36:14Z |
| format | Article |
| id | doaj.art-0578bd9f5d8148389f5b4c37914eed73 |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-09T05:36:14Z |
| publishDate | 2022-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-0578bd9f5d8148389f5b4c37914eed732023-12-03T12:28:02ZengMDPI AGApplied Sciences2076-34172022-07-011215756710.3390/app12157567Experimental Investigation on Jet Vector Deflection Jumping Phenomenon of Coanda Effect NozzleShaoqing Chi0Yunsong Gu1Key Laboratory of Unsteady Aerodynamics and Flow Control, Ministry of Industry and Information Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, ChinaKey Laboratory of Unsteady Aerodynamics and Flow Control, Ministry of Industry and Information Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, ChinaThe Coanda effect nozzle is a fluid thrust vectoring technology that uses the Coanda effect to control jet vector deflection. The jumping phenomenon often occurs in the process of controlling jet vector deflection. This phenomenon leads to the nonlinearity of thrust vector control. It destroys the control performance of the aircraft and brings potential dangers to the safety of the aircraft. The jumping phenomenon occurs in an unsteady flow field different from the traditional flow phenomenon. The flow structure in an unsteady flow field changes with time, so it is not easy to control by the traditional active flow control method. This paper explains the reasons for the jumping phenomenon from two aspects: flow field stability and flow structure. Secondly, the unsteady flow field with the jumping phenomenon is studied and analyzed by a flow visualization experiment and dynamic force measurement. Furthermore, the dynamic modal decomposition (DMD) method is used to extract the characteristic frequencies of the critical vortices causing jets to jump in unsteady flow fields. Finally, a pulsed jet with the same characteristic frequency is used to control the varying vortices in the unsteady flow field. The experimental results show that the active flow control method, which extracts the characteristic frequency of the critical flow field structure by DMD, effectively suppresses the jumping phenomenon in the unsteady flow field. It also linearizes the process of jet nonlinear vector deflection.https://www.mdpi.com/2076-3417/12/15/7567Coanda effectfluid thrust vectoring nozzleactive flow controlthe jumping phenomenonDMD |
| spellingShingle | Shaoqing Chi Yunsong Gu Experimental Investigation on Jet Vector Deflection Jumping Phenomenon of Coanda Effect Nozzle Applied Sciences Coanda effect fluid thrust vectoring nozzle active flow control the jumping phenomenon DMD |
| title | Experimental Investigation on Jet Vector Deflection Jumping Phenomenon of Coanda Effect Nozzle |
| title_full | Experimental Investigation on Jet Vector Deflection Jumping Phenomenon of Coanda Effect Nozzle |
| title_fullStr | Experimental Investigation on Jet Vector Deflection Jumping Phenomenon of Coanda Effect Nozzle |
| title_full_unstemmed | Experimental Investigation on Jet Vector Deflection Jumping Phenomenon of Coanda Effect Nozzle |
| title_short | Experimental Investigation on Jet Vector Deflection Jumping Phenomenon of Coanda Effect Nozzle |
| title_sort | experimental investigation on jet vector deflection jumping phenomenon of coanda effect nozzle |
| topic | Coanda effect fluid thrust vectoring nozzle active flow control the jumping phenomenon DMD |
| url | https://www.mdpi.com/2076-3417/12/15/7567 |
| work_keys_str_mv | AT shaoqingchi experimentalinvestigationonjetvectordeflectionjumpingphenomenonofcoandaeffectnozzle AT yunsonggu experimentalinvestigationonjetvectordeflectionjumpingphenomenonofcoandaeffectnozzle |