Numerical Research on the Jet-Mixing Mechanism of Convergent Nozzle Excited by a Fluidic Oscillator and an Air Tab
Unsteady numerical simulations, coupled with the SST (Shear Stress Transport) k-ω turbulence model, were conducted to study the mixing-enhancement characteristics of the excited jet generated by the fluidic oscillator and the air tab in a single channel convergent nozzle with an inlet total pressure...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-01-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/16/3/1412 |
| _version_ | 1797624668934373376 |
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| author | Ming Li Zhijun Lei Hanliu Deng Xiaoqing Ouyang Yanfeng Zhang Xingen Lu Gang Xu Junqiang Zhu |
| author_facet | Ming Li Zhijun Lei Hanliu Deng Xiaoqing Ouyang Yanfeng Zhang Xingen Lu Gang Xu Junqiang Zhu |
| author_sort | Ming Li |
| collection | DOAJ |
| description | Unsteady numerical simulations, coupled with the SST (Shear Stress Transport) k-ω turbulence model, were conducted to study the mixing-enhancement characteristics of the excited jet generated by the fluidic oscillator and the air tab in a single channel convergent nozzle with an inlet total pressure of 140–200 kPa. Compared with the steady air-tab jet, the sweeping jet generated by the fluidic oscillator has roughly the same penetration in the main flow, but it can induce streamwise vortices and planar vortices of larger scale and longer duration, which is beneficial to enhance jet mixing efficiency in the range of 1.0 D<i><sub>N</sub></i> (D<i><sub>N</sub></i> represents the diameter of the main nozzle outlet) downstream from the main nozzle. When <i>x</i> > 1.0 D<i><sub>N</sub></i>, the jet mixing is mainly dominated by the shear layer between the main jet and the ambient. As the sweeping jet suppresses the expansion of the main jet, which reduces the contact area between the main jet and the ambient, its mixing efficiency is less than that of the air tab in this region. With the increasing inlet total pressure of the fluidic oscillator, the influence range of the sweeping jet is increased, but its mixing efficiency does not increase significantly. In general, the fluidic oscillator can use a small jet flow (<5%) to achieve a high mixing efficiency (i.e., 60% at <i>x</i> = 2.0 D<i><sub>N</sub></i>) at the expense of low total pressure loss (<2.3%), which indicates that it has good engineering applicability. |
| first_indexed | 2024-03-11T09:45:50Z |
| format | Article |
| id | doaj.art-372a807e076c43f791c1d9f26e0c594b |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-11T09:45:50Z |
| publishDate | 2023-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-372a807e076c43f791c1d9f26e0c594b2023-11-16T16:37:07ZengMDPI AGEnergies1996-10732023-01-01163141210.3390/en16031412Numerical Research on the Jet-Mixing Mechanism of Convergent Nozzle Excited by a Fluidic Oscillator and an Air TabMing Li0Zhijun Lei1Hanliu Deng2Xiaoqing Ouyang3Yanfeng Zhang4Xingen Lu5Gang Xu6Junqiang Zhu7Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013, ChinaKey Laboratory of Light-Duty Gas Turbine, Institute of Engineering Thermophysics, C.A.S., Beijing 100190, ChinaKey Laboratory of Light-Duty Gas Turbine, Institute of Engineering Thermophysics, C.A.S., Beijing 100190, ChinaResearch Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013, ChinaKey Laboratory of Light-Duty Gas Turbine, Institute of Engineering Thermophysics, C.A.S., Beijing 100190, ChinaKey Laboratory of Light-Duty Gas Turbine, Institute of Engineering Thermophysics, C.A.S., Beijing 100190, ChinaKey Laboratory of Light-Duty Gas Turbine, Institute of Engineering Thermophysics, C.A.S., Beijing 100190, ChinaKey Laboratory of Light-Duty Gas Turbine, Institute of Engineering Thermophysics, C.A.S., Beijing 100190, ChinaUnsteady numerical simulations, coupled with the SST (Shear Stress Transport) k-ω turbulence model, were conducted to study the mixing-enhancement characteristics of the excited jet generated by the fluidic oscillator and the air tab in a single channel convergent nozzle with an inlet total pressure of 140–200 kPa. Compared with the steady air-tab jet, the sweeping jet generated by the fluidic oscillator has roughly the same penetration in the main flow, but it can induce streamwise vortices and planar vortices of larger scale and longer duration, which is beneficial to enhance jet mixing efficiency in the range of 1.0 D<i><sub>N</sub></i> (D<i><sub>N</sub></i> represents the diameter of the main nozzle outlet) downstream from the main nozzle. When <i>x</i> > 1.0 D<i><sub>N</sub></i>, the jet mixing is mainly dominated by the shear layer between the main jet and the ambient. As the sweeping jet suppresses the expansion of the main jet, which reduces the contact area between the main jet and the ambient, its mixing efficiency is less than that of the air tab in this region. With the increasing inlet total pressure of the fluidic oscillator, the influence range of the sweeping jet is increased, but its mixing efficiency does not increase significantly. In general, the fluidic oscillator can use a small jet flow (<5%) to achieve a high mixing efficiency (i.e., 60% at <i>x</i> = 2.0 D<i><sub>N</sub></i>) at the expense of low total pressure loss (<2.3%), which indicates that it has good engineering applicability.https://www.mdpi.com/1996-1073/16/3/1412mixing mechanismair tabfluidic oscillatorsweeping jetconvergent nozzle |
| spellingShingle | Ming Li Zhijun Lei Hanliu Deng Xiaoqing Ouyang Yanfeng Zhang Xingen Lu Gang Xu Junqiang Zhu Numerical Research on the Jet-Mixing Mechanism of Convergent Nozzle Excited by a Fluidic Oscillator and an Air Tab Energies mixing mechanism air tab fluidic oscillator sweeping jet convergent nozzle |
| title | Numerical Research on the Jet-Mixing Mechanism of Convergent Nozzle Excited by a Fluidic Oscillator and an Air Tab |
| title_full | Numerical Research on the Jet-Mixing Mechanism of Convergent Nozzle Excited by a Fluidic Oscillator and an Air Tab |
| title_fullStr | Numerical Research on the Jet-Mixing Mechanism of Convergent Nozzle Excited by a Fluidic Oscillator and an Air Tab |
| title_full_unstemmed | Numerical Research on the Jet-Mixing Mechanism of Convergent Nozzle Excited by a Fluidic Oscillator and an Air Tab |
| title_short | Numerical Research on the Jet-Mixing Mechanism of Convergent Nozzle Excited by a Fluidic Oscillator and an Air Tab |
| title_sort | numerical research on the jet mixing mechanism of convergent nozzle excited by a fluidic oscillator and an air tab |
| topic | mixing mechanism air tab fluidic oscillator sweeping jet convergent nozzle |
| url | https://www.mdpi.com/1996-1073/16/3/1412 |
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