Double diffusive convection in a rotating anisotropic porous layer saturated with viscoelastic fluid

The onset of double diffusive convection in a binary viscoelastic fluid-saturated anisotropic rotating porous layer is studied using a linear and a weakly non-linear stability analyses. The modified Darcy law for the viscoelastic fluid of the Oldroyd type is used to model the momentum equation. The onset criterion for stationary and oscillatory convection is derived analytically. There is a competition between the processes of thermal, solute diffusions and viscoelasticity that causes the convection to set in through oscillatory rather than stationary. The effect of anisotropy parameters, Vadasz number, relaxation and retardation parameters on the stability of the system is investigated. It is found that contrary to their usual influence on the onset of convection in the absence of rotation, the thermal anisotropy parameter and Vadasz number show contrasting effect on the onset criterion. The non-linear theory based on the truncated representation of Fourier series method is used to find the transient heat and mass transfer. The effect of various parameters on heat and mass transfer is also considered.