Fluid dynamics of a bistable diverter under ultrasonic excitation - Part II: Flow visualisation and fundamental mechanisms
The switching mechanism and underlying flow physics of an actively controlled fluidic device are investigated using both large eddy simulation (LES) and particle imaging velocimetry (PIV). The fluidic device considered herein uses acoustic excitation of inherent flow instabilities to control the mov...
| Main Authors: | , , , |
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| Format: | Journal article |
| Language: | English |
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American Society of Mechanical Engineers
2021
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| _version_ | 1797106624415924224 |
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| author | Mair, M Bacic, M Chakravarthy, K Williams, B |
| author_facet | Mair, M Bacic, M Chakravarthy, K Williams, B |
| author_sort | Mair, M |
| collection | OXFORD |
| description | The switching mechanism and underlying flow physics of an actively controlled fluidic device are investigated using both large eddy simulation (LES) and particle imaging velocimetry (PIV). The fluidic device considered herein uses acoustic excitation of inherent flow instabilities to control the movement of the jet. Acoustic excitation at the preferred frequency is shown to yield high saturation amplitudes resulting in the formation of large vortical structures that do not undergo pairing. Basic flow features including the shear layer instabilities are further examined to explain why the excitation mode that triggers the switching process changes from a shear layer-based mode (Stθ=0.012) to a jet orifice mode (Sth=0.25) as the Reynolds number increases. |
| first_indexed | 2024-03-07T07:05:09Z |
| format | Journal article |
| id | oxford-uuid:b2028317-ab3a-4fd7-81ff-af993b0fc86e |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T07:05:09Z |
| publishDate | 2021 |
| publisher | American Society of Mechanical Engineers |
| record_format | dspace |
| spelling | oxford-uuid:b2028317-ab3a-4fd7-81ff-af993b0fc86e2022-04-22T09:56:56ZFluid dynamics of a bistable diverter under ultrasonic excitation - Part II: Flow visualisation and fundamental mechanismsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:b2028317-ab3a-4fd7-81ff-af993b0fc86eEnglishSymplectic ElementsAmerican Society of Mechanical Engineers2021Mair, MBacic, MChakravarthy, KWilliams, BThe switching mechanism and underlying flow physics of an actively controlled fluidic device are investigated using both large eddy simulation (LES) and particle imaging velocimetry (PIV). The fluidic device considered herein uses acoustic excitation of inherent flow instabilities to control the movement of the jet. Acoustic excitation at the preferred frequency is shown to yield high saturation amplitudes resulting in the formation of large vortical structures that do not undergo pairing. Basic flow features including the shear layer instabilities are further examined to explain why the excitation mode that triggers the switching process changes from a shear layer-based mode (Stθ=0.012) to a jet orifice mode (Sth=0.25) as the Reynolds number increases. |
| spellingShingle | Mair, M Bacic, M Chakravarthy, K Williams, B Fluid dynamics of a bistable diverter under ultrasonic excitation - Part II: Flow visualisation and fundamental mechanisms |
| title | Fluid dynamics of a bistable diverter under ultrasonic excitation - Part II: Flow visualisation and fundamental mechanisms |
| title_full | Fluid dynamics of a bistable diverter under ultrasonic excitation - Part II: Flow visualisation and fundamental mechanisms |
| title_fullStr | Fluid dynamics of a bistable diverter under ultrasonic excitation - Part II: Flow visualisation and fundamental mechanisms |
| title_full_unstemmed | Fluid dynamics of a bistable diverter under ultrasonic excitation - Part II: Flow visualisation and fundamental mechanisms |
| title_short | Fluid dynamics of a bistable diverter under ultrasonic excitation - Part II: Flow visualisation and fundamental mechanisms |
| title_sort | fluid dynamics of a bistable diverter under ultrasonic excitation part ii flow visualisation and fundamental mechanisms |
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