Onset of oscillatory convection in a porous cylinder saturated with a viscoelastic fluid

A stability analysis determining the onset of oscillatory convection in a bounded cylindrical cavity containing a viscoelastic fluid saturated porous medium is performed for insulated sidewalls, isothermal top wall, and bottom heated by constant heat flux or constant temperature. The dependence of the critical Darcy-Rayleigh number and the preferred convective motion on both the aspect ratio of the cylinder and the viscoelastic parameters is established. The differences between bottom constant heat flux heating and bottom constant temperature heating are compared. (c) 2007 American Institute of Physics.