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Transition from periodic to chaotic AC electroosmotic flows near electric double layer
Author(s) -
Hu Zhongyan,
Zhao Tianyun,
Zhao Wei,
Yang Fang,
Wang Hongxun,
Wang Kaige,
Bai Jintao,
Wang Guiren
Publication year - 2021
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.17148
Subject(s) - reynolds number , mechanics , electric field , oscillation (cell signaling) , newtonian fluid , anemometer , microfluidics , chemistry , flow (mathematics) , particle image velocimetry , physics , thermodynamics , turbulence , biochemistry , quantum mechanics
Electroosmotic flows (EOFs) on insulated interfacial surface commonly exists as interfacial flows. Previously theoretical studies indicate that EOFs of Newtonian fluids on the insulated interfacial surface are steady in microchannels with symmetric zeta potentials (Suresh and Homsy, Physics of Fluids, 2004, 16, 2,349). Restricted by flow diagnostic methods in microfluidics, few velocity measurements of instantaneous EOFs have been reported, and the existence of unsteady EOFs on the insulated surface remains unclear. In this investigation, the velocity fluctuations of EOFs generated under AC electric field (named as ACFEOF) overlapped on a steady pressure‐driven flow are measured by laser induced fluorescence photobleaching anemometer, at the diffuse electric double layer (EDL) on the bottom wall far from electrodes. Chaotic velocity fluctuations according to unsteady ACFEOF has been, for the first time, observed. Stokes number ( St ) and electrical Reynolds number ( Re E ) related to oscillation and electro‐inertial effect are suggested to control chaotic ACFEOF.