Significance of modulated gravity on triple‐diffusive convection of liquids through permeable media: Ginzburg–Landau analysis of heat and mass transfer

Source abstract

Abstract The importance of modulated gravity in the nonlinear dynamics of Newtonian fluids flowing through a permeable Darcy porous medium in achieving fluid buoyancy control, porous media dynamics, and microgravity studies, which are important for environmental science and space exploration, is growing, particularly in the context of triple‐diffusive convection. However, limited information is available on the dynamics of Newtonian fluids undergoing triple‐diffusive convection through permeable media when modulated gravity is introduced, particularly using the Ginzburg–Landau technique. In this case, the fluid convective system is subjected to vertical gravitational vibrations. The physical system considered involves a porous layer, stretched indefinitely in the x ‐direction, sandwiched between two parallel plates at z = 0 and z = d . The temperature and concentration of the bottom plate are higher than those at the top plate due to heating, salting, and saturation of the porous layer with Newtonian fluid from below. The gravitational acceleration is time‐dependent, consisting of both a constant gravity term and a time‐dependent oscillatory component. The amplitude of gravity modulation is assumed to be small, relevant to practical applications. The presence of a third diffusive component increases the critical thermal Darcy–Rayleigh number required for the onset of convection, demonstrating that triple‐diffusive convection has a higher threshold than double‐diffusive convection. The modulation amplitude () plays a critical role in the behavior of disturbance amplitude, demonstrating that significant variations in convection characteristics are contingent upon the presence of gravitational modulation.