Condition of the onset and nonlinear regimes of convection of a three-component isothermal mixture in a porous rectangle under modulation of the concentration gradient
N. S. Bulgakova · Fluid Dynamics · 2012
Convection of an isothermal three-component mixture saturating a porous block with a rectangular cross-section is investigated numerically when the concentration gradient of one of the components is modulated about a certain mean value. The shape of the neutral curves separating the growing and decaying disturbances in the amplitude-modulation frequency plane is investigated for various diffusion Rayleigh numbers. The results of calculations based on the linearized and complete systems of equations which describe convection of a mixture in a porous medium are analyzed and compared. The supercritical regimes of concentration convection are studied for steady-state boundary conditions and in the case of a periodic modulation of the concentration gradient of one of the components.