Enhancing subsonic ejector performance by incorporating a fluidic oscillator as the primary nozzle: a numerical investigation
Primary flow structures affect ejector performance by impacting momentum transfer to the secondary flow and pressure reduction in the suction chamber. This study investigated the potential benefits of oscillating the primary flow in ejectors to enhance the shear-turbulence mixing and momentum exchan...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2023-11-01
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| Series: | International Journal of Thermofluids |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2666202723001453 |
| _version_ | 1797401718107930624 |
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| author | Mahdi Tavakoli Mahdi Nili-Ahmadabadi Amir Joulaei Man Yeong Ha |
| author_facet | Mahdi Tavakoli Mahdi Nili-Ahmadabadi Amir Joulaei Man Yeong Ha |
| author_sort | Mahdi Tavakoli |
| collection | DOAJ |
| description | Primary flow structures affect ejector performance by impacting momentum transfer to the secondary flow and pressure reduction in the suction chamber. This study investigated the potential benefits of oscillating the primary flow in ejectors to enhance the shear-turbulence mixing and momentum exchange between the primary and secondary flows and improve the entrainment ratio. A vortex-based fluidic oscillator was scaled down and designed to serve as the primary nozzle in a two-dimensional subsonic ejector, embedded between the secondary channels. Prior to installation, optimal values for the nozzle exit position and mixing chamber height were obtained through a parametric study and used in the ejector with the oscillator. To evaluate the impact of the fluidic oscillator on the ejector entrainment ratio, unsteady Reynolds-averaged Navier–Stokes equations were solved using the k–ε standard and k–ω shear-stress transport turbulence models in the Fluent 2022 R2 software. The results indicated that a harmonically oscillating primary flow was generated, increasing the mixing entrainment and momentum transfer while reducing the pressure in the suction and mixing chambers. The oscillator improved the ejector's entrainment ratio by 38.3% compared to the baseline, and 11.6% compared to the parametrically optimized ejector. It also expanded the ejector's performance range. |
| first_indexed | 2024-03-09T02:14:09Z |
| format | Article |
| id | doaj.art-d2de4fa840ba4ed19a834e2392d4eda7 |
| institution | Directory Open Access Journal |
| issn | 2666-2027 |
| language | English |
| last_indexed | 2024-03-09T02:14:09Z |
| publishDate | 2023-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | International Journal of Thermofluids |
| spelling | doaj.art-d2de4fa840ba4ed19a834e2392d4eda72023-12-07T05:30:43ZengElsevierInternational Journal of Thermofluids2666-20272023-11-0120100429Enhancing subsonic ejector performance by incorporating a fluidic oscillator as the primary nozzle: a numerical investigationMahdi Tavakoli0Mahdi Nili-Ahmadabadi1Amir Joulaei2Man Yeong Ha3Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, IranDepartment of Mechanical Engineering, Isfahan University of Technology, Isfahan, Iran; Corresponding authorDepartment of Mechanical Engineering, Isfahan University of Technology, Isfahan, IranSchool of Mechanical Engineering, Pusan National University, Busan, Republic of Korea; Corresponding authorPrimary flow structures affect ejector performance by impacting momentum transfer to the secondary flow and pressure reduction in the suction chamber. This study investigated the potential benefits of oscillating the primary flow in ejectors to enhance the shear-turbulence mixing and momentum exchange between the primary and secondary flows and improve the entrainment ratio. A vortex-based fluidic oscillator was scaled down and designed to serve as the primary nozzle in a two-dimensional subsonic ejector, embedded between the secondary channels. Prior to installation, optimal values for the nozzle exit position and mixing chamber height were obtained through a parametric study and used in the ejector with the oscillator. To evaluate the impact of the fluidic oscillator on the ejector entrainment ratio, unsteady Reynolds-averaged Navier–Stokes equations were solved using the k–ε standard and k–ω shear-stress transport turbulence models in the Fluent 2022 R2 software. The results indicated that a harmonically oscillating primary flow was generated, increasing the mixing entrainment and momentum transfer while reducing the pressure in the suction and mixing chambers. The oscillator improved the ejector's entrainment ratio by 38.3% compared to the baseline, and 11.6% compared to the parametrically optimized ejector. It also expanded the ejector's performance range.http://www.sciencedirect.com/science/article/pii/S2666202723001453Fluidic oscillatorvelocity fluctuationejectorsecondary mass flow rateentrainment ratiomixing shear layer |
| spellingShingle | Mahdi Tavakoli Mahdi Nili-Ahmadabadi Amir Joulaei Man Yeong Ha Enhancing subsonic ejector performance by incorporating a fluidic oscillator as the primary nozzle: a numerical investigation International Journal of Thermofluids Fluidic oscillator velocity fluctuation ejector secondary mass flow rate entrainment ratio mixing shear layer |
| title | Enhancing subsonic ejector performance by incorporating a fluidic oscillator as the primary nozzle: a numerical investigation |
| title_full | Enhancing subsonic ejector performance by incorporating a fluidic oscillator as the primary nozzle: a numerical investigation |
| title_fullStr | Enhancing subsonic ejector performance by incorporating a fluidic oscillator as the primary nozzle: a numerical investigation |
| title_full_unstemmed | Enhancing subsonic ejector performance by incorporating a fluidic oscillator as the primary nozzle: a numerical investigation |
| title_short | Enhancing subsonic ejector performance by incorporating a fluidic oscillator as the primary nozzle: a numerical investigation |
| title_sort | enhancing subsonic ejector performance by incorporating a fluidic oscillator as the primary nozzle a numerical investigation |
| topic | Fluidic oscillator velocity fluctuation ejector secondary mass flow rate entrainment ratio mixing shear layer |
| url | http://www.sciencedirect.com/science/article/pii/S2666202723001453 |
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