A Sequence of Electrokinetic-Instability Bifurcations Resulting in a Chaotic-Flow Regime

摘要

Recently, electroosmotic phenomena have attracted great attention in connection with the rapid development of micro-, nano-, and biotechnologies. Among numerous modern applications, we note micropumps, biological membranes, and cells, and applications in the pharmaceutical industry, in medical diagnostics, and in the fields related to the fabrication of microchips. In the presence of an ion flux to a selective surface (semipermeable electric membranes, electrodes, or artificial systems of micro- or nanochannels), a new type of electrohydrodynamic instability, the so-called electrokinetic or electroconvective instability responsible for the occurrence of supercritical currents, is observed. In, direct numerical simulation of the initial stages of evolution of electroconvective instability was carried out, the basic coherent structures arising under an initial instability were revealed, and the physical mechanisms of interaction of these structures and the manifestations of the secondary instability were determined.