Inertio-elastic flow instability in a micro-cavity swept by a visco-elastic fluid
Inertio-elastic instability characteristics of visco-elastic fluids sweeping a micro-cavity mounted in a micro-duct have been investigated in order to develop a effective micro mixer. The cavity depth, the cavity length and the width of the wider flow path were fixed at 200, 1,000 and 400 μm, respec...
| Main Authors: | , , |
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| Format: | Article |
| Language: | Japanese |
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The Japan Society of Mechanical Engineers
2015-03-01
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| Series: | Nihon Kikai Gakkai ronbunshu |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/transjsme/81/823/81_14-00650/_pdf/-char/en |
| _version_ | 1797988637183311872 |
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| author | Hiroshi SUZUKI Ruri HIDEMA Yoshiyuki KOMODA |
| author_facet | Hiroshi SUZUKI Ruri HIDEMA Yoshiyuki KOMODA |
| author_sort | Hiroshi SUZUKI |
| collection | DOAJ |
| description | Inertio-elastic instability characteristics of visco-elastic fluids sweeping a micro-cavity mounted in a micro-duct have been investigated in order to develop a effective micro mixer. The cavity depth, the cavity length and the width of the wider flow path were fixed at 200, 1,000 and 400 μm, respectively while the solvent Reynolds number was changed from 0.100 to 100. As a visco-elastic fluid, a cationic surfactant/counter-ion system was applied. The molar ratio of counter-ion to surfactant was changed from 1.5 to 10 in order to control rheological characteristics of the fluid. Flow visualization experiments were performed with a high-speed camera mounted on a microscope. From the results, it was that a tonguing motion of the separation fluid bubble tip formed in the downstream region in the cavity occurs at a certain Weissenberg number larger than 200 due to the inertio-elastic instability. The fluctuating bulge structure was also observed on the upstream side wall of the cavity in a higher range of the Weissenberg number. These characteristics were considered to be effective for a mixing process. It was also found that the separation bubble size is determined with Weissenberg number for all fluids treated in this study, but the previous correlation suggested for a macro-scale system does not agree with the present results. This indicated that some different relaxation structure exists in a micro-scale system. |
| first_indexed | 2024-04-11T08:07:25Z |
| format | Article |
| id | doaj.art-c8f8d3fd0e154f0bbd0d04e41045e6eb |
| institution | Directory Open Access Journal |
| issn | 2187-9761 |
| language | Japanese |
| last_indexed | 2024-04-11T08:07:25Z |
| publishDate | 2015-03-01 |
| publisher | The Japan Society of Mechanical Engineers |
| record_format | Article |
| series | Nihon Kikai Gakkai ronbunshu |
| spelling | doaj.art-c8f8d3fd0e154f0bbd0d04e41045e6eb2022-12-22T04:35:29ZjpnThe Japan Society of Mechanical EngineersNihon Kikai Gakkai ronbunshu2187-97612015-03-018182314-0065014-0065010.1299/transjsme.14-00650transjsmeInertio-elastic flow instability in a micro-cavity swept by a visco-elastic fluidHiroshi SUZUKI0Ruri HIDEMA1Yoshiyuki KOMODA2Department of Chemical Science and Engineering, Kobe UniversityOrganization of Advanced Science and Technology, Kobe UniversityDepartment of Chemical Science and Engineering, Kobe UniversityInertio-elastic instability characteristics of visco-elastic fluids sweeping a micro-cavity mounted in a micro-duct have been investigated in order to develop a effective micro mixer. The cavity depth, the cavity length and the width of the wider flow path were fixed at 200, 1,000 and 400 μm, respectively while the solvent Reynolds number was changed from 0.100 to 100. As a visco-elastic fluid, a cationic surfactant/counter-ion system was applied. The molar ratio of counter-ion to surfactant was changed from 1.5 to 10 in order to control rheological characteristics of the fluid. Flow visualization experiments were performed with a high-speed camera mounted on a microscope. From the results, it was that a tonguing motion of the separation fluid bubble tip formed in the downstream region in the cavity occurs at a certain Weissenberg number larger than 200 due to the inertio-elastic instability. The fluctuating bulge structure was also observed on the upstream side wall of the cavity in a higher range of the Weissenberg number. These characteristics were considered to be effective for a mixing process. It was also found that the separation bubble size is determined with Weissenberg number for all fluids treated in this study, but the previous correlation suggested for a macro-scale system does not agree with the present results. This indicated that some different relaxation structure exists in a micro-scale system.https://www.jstage.jst.go.jp/article/transjsme/81/823/81_14-00650/_pdf/-char/envisco-elastic fluidmicro-cavityinertio-elastic instabilitymicro-mxingsurfactant solutionvisualization |
| spellingShingle | Hiroshi SUZUKI Ruri HIDEMA Yoshiyuki KOMODA Inertio-elastic flow instability in a micro-cavity swept by a visco-elastic fluid Nihon Kikai Gakkai ronbunshu visco-elastic fluid micro-cavity inertio-elastic instability micro-mxing surfactant solution visualization |
| title | Inertio-elastic flow instability in a micro-cavity swept by a visco-elastic fluid |
| title_full | Inertio-elastic flow instability in a micro-cavity swept by a visco-elastic fluid |
| title_fullStr | Inertio-elastic flow instability in a micro-cavity swept by a visco-elastic fluid |
| title_full_unstemmed | Inertio-elastic flow instability in a micro-cavity swept by a visco-elastic fluid |
| title_short | Inertio-elastic flow instability in a micro-cavity swept by a visco-elastic fluid |
| title_sort | inertio elastic flow instability in a micro cavity swept by a visco elastic fluid |
| topic | visco-elastic fluid micro-cavity inertio-elastic instability micro-mxing surfactant solution visualization |
| url | https://www.jstage.jst.go.jp/article/transjsme/81/823/81_14-00650/_pdf/-char/en |
| work_keys_str_mv | AT hiroshisuzuki inertioelasticflowinstabilityinamicrocavitysweptbyaviscoelasticfluid AT rurihidema inertioelasticflowinstabilityinamicrocavitysweptbyaviscoelasticfluid AT yoshiyukikomoda inertioelasticflowinstabilityinamicrocavitysweptbyaviscoelasticfluid |