The Effects of Compressibility on the Performance and Modal Structures of a Sweeping Jet Emitted from Various Scales of a Fluidic Oscillator
Investigations of fluidic oscillators, or sweeping jet actuators, have primarily been conducted within the incompressible flow regime, which limits the accuracy of estimating fluidic oscillator performance for compressible flows. The objective of this study was to evaluate the effects of gas compres...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-07-01
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| Series: | Fluids |
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| Online Access: | https://www.mdpi.com/2311-5521/7/7/251 |
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| author | Daniel J. Portillo Eugene Hoffman Matt Garcia Elijah LaLonde Christopher Combs R. Lyle Hood |
| author_facet | Daniel J. Portillo Eugene Hoffman Matt Garcia Elijah LaLonde Christopher Combs R. Lyle Hood |
| author_sort | Daniel J. Portillo |
| collection | DOAJ |
| description | Investigations of fluidic oscillators, or sweeping jet actuators, have primarily been conducted within the incompressible flow regime, which limits the accuracy of estimating fluidic oscillator performance for compressible flows. The objective of this study was to evaluate the effects of gas compressibility on the performance of a fluidic oscillator. A commonly used fluidic oscillator geometry (the Bray geometry) was scaled to five different sizes, 3D printed, and tested over a range of air flow rates. High-speed Schlieren images captured the sweeping jet exiting the fluidic oscillators, and custom MATLAB algorithms were used to calculate the oscillation frequencies and angles. A spectral proper orthogonal decomposition (SPOD) method was used to identify and compare the mode structures within the flow fields. All the results were compared using dimensionless parameters to observe performance trends. The results showed that the oscillation frequencies were directly proportional to the flow rate, while the oscillation angles were inversely proportional to the flow rate, regardless of scale size. The angular velocities were not proportional to the flow rate or scale size and exhibited maxima within the evaluated ranges. For all scale sizes, the mode structures were symmetric across the centerlines of the fluidic oscillators and extended further beyond the fluidic oscillators at higher flow rates. These results enable the prediction of fluidic oscillator performance, which can significantly improve the design process for an application where a fluidic oscillator may be used, such as aerospace applications, power generation, heat exchangers, or medical devices. |
| first_indexed | 2024-03-09T03:26:11Z |
| format | Article |
| id | doaj.art-29700d5586144dc38e1fc046a0908d83 |
| institution | Directory Open Access Journal |
| issn | 2311-5521 |
| language | English |
| last_indexed | 2024-03-09T03:26:11Z |
| publishDate | 2022-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Fluids |
| spelling | doaj.art-29700d5586144dc38e1fc046a0908d832023-12-03T15:02:17ZengMDPI AGFluids2311-55212022-07-017725110.3390/fluids7070251The Effects of Compressibility on the Performance and Modal Structures of a Sweeping Jet Emitted from Various Scales of a Fluidic OscillatorDaniel J. Portillo0Eugene Hoffman1Matt Garcia2Elijah LaLonde3Christopher Combs4R. Lyle Hood5Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX 78249, USADepartment of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX 78249, USADepartment of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX 78249, USADepartment of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX 78249, USADepartment of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX 78249, USADepartment of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX 78249, USAInvestigations of fluidic oscillators, or sweeping jet actuators, have primarily been conducted within the incompressible flow regime, which limits the accuracy of estimating fluidic oscillator performance for compressible flows. The objective of this study was to evaluate the effects of gas compressibility on the performance of a fluidic oscillator. A commonly used fluidic oscillator geometry (the Bray geometry) was scaled to five different sizes, 3D printed, and tested over a range of air flow rates. High-speed Schlieren images captured the sweeping jet exiting the fluidic oscillators, and custom MATLAB algorithms were used to calculate the oscillation frequencies and angles. A spectral proper orthogonal decomposition (SPOD) method was used to identify and compare the mode structures within the flow fields. All the results were compared using dimensionless parameters to observe performance trends. The results showed that the oscillation frequencies were directly proportional to the flow rate, while the oscillation angles were inversely proportional to the flow rate, regardless of scale size. The angular velocities were not proportional to the flow rate or scale size and exhibited maxima within the evaluated ranges. For all scale sizes, the mode structures were symmetric across the centerlines of the fluidic oscillators and extended further beyond the fluidic oscillators at higher flow rates. These results enable the prediction of fluidic oscillator performance, which can significantly improve the design process for an application where a fluidic oscillator may be used, such as aerospace applications, power generation, heat exchangers, or medical devices.https://www.mdpi.com/2311-5521/7/7/251fluidic oscillatorsweeping jet actuatorflow controlturbulencecompressibilitymodal analysis |
| spellingShingle | Daniel J. Portillo Eugene Hoffman Matt Garcia Elijah LaLonde Christopher Combs R. Lyle Hood The Effects of Compressibility on the Performance and Modal Structures of a Sweeping Jet Emitted from Various Scales of a Fluidic Oscillator Fluids fluidic oscillator sweeping jet actuator flow control turbulence compressibility modal analysis |
| title | The Effects of Compressibility on the Performance and Modal Structures of a Sweeping Jet Emitted from Various Scales of a Fluidic Oscillator |
| title_full | The Effects of Compressibility on the Performance and Modal Structures of a Sweeping Jet Emitted from Various Scales of a Fluidic Oscillator |
| title_fullStr | The Effects of Compressibility on the Performance and Modal Structures of a Sweeping Jet Emitted from Various Scales of a Fluidic Oscillator |
| title_full_unstemmed | The Effects of Compressibility on the Performance and Modal Structures of a Sweeping Jet Emitted from Various Scales of a Fluidic Oscillator |
| title_short | The Effects of Compressibility on the Performance and Modal Structures of a Sweeping Jet Emitted from Various Scales of a Fluidic Oscillator |
| title_sort | effects of compressibility on the performance and modal structures of a sweeping jet emitted from various scales of a fluidic oscillator |
| topic | fluidic oscillator sweeping jet actuator flow control turbulence compressibility modal analysis |
| url | https://www.mdpi.com/2311-5521/7/7/251 |
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