ABSTRAKT

Linear stability analysis of double-diffusive convection in a binary fluid layer/saturated porous layer is performed. The prime objective of this study is to investigate the influence of time-periodic vertical vibrations on the onset threshold. The regular perturbation method is used to compute critical Rayleigh number. The first nontrivial correction to the critical Rayleigh number is calculated as a function of frequency of modulation, solute Rayleigh number, Lewis number, Prandtl number, Darcy number, normalized porosity, and viscosity ratio. In the degenerate cases of Brinkman model the results of Darcy porous layer and viscous fluid layer are recovered, respectively, for very small and large Darcy number. In general, gravity modulation exhibits a stabilizing effect Effective control of convection is achieved by proper tuning of governing parameters. The results of this study are useful in the areas of crystal growth in microgravity conditions and also in bridging the gap between the results of Darcy and viscous fluid layer limits.