ELECTROCONVECTION INSTABILITY OF POORLY CONDUCTING FLUID IN ALTERNATING ELECTRIC FIELD

Abstract

The flat horizontal layer of the poorly conducting fluid is placed in the alternating electric field and heated from above. Its behavior is investigated in the electroconvection low-mode model. The approximation in which density and conductivity of the fluid are linearly dependent on temperature is used. Linear instability is analyzed by means of the Floquet theory. The system of eight differential equations, which describe the motion of the fluid, is integrated using the Runge-Kutta-Merson fourth-order method. The marginal stability curves are plotted in coordinates “wave number – nondimensional electric parameter.” The critical values of the wave number and the nondimensional electric parameter are determined for various external influence frequencies. The nonlinear regimes of the fluid flow are investigated at the critical value of the wave number. The fluid electroconvection flow intensity as a function of the nondimensional electric parameter is plotted. The various types of the oscillation regimes are discovered, and the competition regions of different electroconvection modes with various flow intensities are found.