Magnetic effect for electrochemically driven cellular convection

Hydrodynamic instability analogous to Rayleigh-Benard convection is observe d in an electrolytic solution between two parallel copper wire electrodes. The laser interferometric technique can reveal the dissipation structure cr eated by the motion of the fluid, which is controlled electrochemically. It is shown that under the presence of horizontal magnetic field the roll cel ls move horizontally along the electrodes. The electrochemically driven con vection is simply controlled and monitored by setting and measuring the ele ctrochemical parameters and forms many kinds of spatiotemporal patterns, es pecially under the magnetic field. The phenomenon is modeled by considering a Boussinesq fluid under a concentration gradient. The stability of the re sulting equations is studied by linear stability analysis. The time depende nt nonlinear system is investigated numerically and the main features of th e experimental response are reproduced. [S1063-651X(99)05006-0].