Thermodiffusive magneto convection in ferrofluids with two-frequency gravity modulation

Thermosolutal convection in magnetic fluids is considered in the presence of vertical magnetic field and bifrequency vertical vibrations. Using the Floquet theory, the regions of parametric instability have been obtained for different values of parameters and threshold acceleration necessary for instability has been found numerically. With two-frequency forcing, bicritical point has been observed where subharmonic instability and harmonic instability simultaneously occur with distinct values of the wave numbers. The change in concentration of magnetic particles in the magnetic fluids has been found to affect the instability behavior and the threshold acceleration. (C) 2004 Elsevier B.V. All rights reserved.