The effect of rotation on the onset of convection in compfessible Walters‘ (model B‘) elastico-viscous fluid heated from below saturating a porous medium is considered. For the porous medium, the Brinkman model is employed and Walters‘ (model B‘) fluid used to characterize the viscoelastic fluid. By applying normal mode analysis method, the dispersion relation has been derived and solved analytically. It is observed that the medium permeability, compressibility, gravity field and vscoelasticity introduce oscillatory modes. For stationary convection, the rotation has stabilizing effect whereas Darcy number and medium permeability have destabilizing/stabilizing effect on the system under certain conditions. and Obsahuje seznam literatury a názvosloví
The present paper investigates the thermal convection in Walters‘ (model B‘) fluid saturated by a porous medium in the presence of uniform vertical magnetic field. For the porous medium, Brinkman model is employed and Walters‘ (model B‘) fluid model is used to describe the rheological behavior of elastico-viscous fluid. By applying normal mode analysis method, the dispersion relation has been derived and solved analytically. It is observed that the magnetic field and viscoelasticity introduce oscillatory modes. For stationary convection, it is observed that the Walters‘ (model B‘) elastico-viscous fluid behaves like an ordinary Newtonian fluid. The effects of Darcy number, magnetic field and medium permeability have been discussed analytically and numerically in detail. The case of overstability has also been discussed and a sufficient condition for the non-existence of overstability is derived. and Obsahuje seznam literatury, názvosloví a řeckých znaků