Thermal Convection of Micropolar Fluid in the Presence of Suspended Particles and Rotation Saturating a Porous Medium

A study has been made of the convection of micropolar fluids heated from below in the presence of suspended particles (fine dust) and uniform vertical rotation Ω(0, 0, Ω) in a porous medium. The effect of Coriolis forces on the stability is chosen along the direction of the gravitational field. It is found that the presence of coupling between thermal and micropolar effects, rotation parameter, medium permeability and suspended particles may introduce overstability in the system. Using the Boussinesq approximation, the linearized stability theory and normal mode analysis, the exact solutions are obtained for the case of two free boundaries. Graphs have been plotted by giving numerical values to the parameters accounting for rotation Ω(0, 0, Ω) medium permeability, dynamic microrotation viscosity K and coefficient of angular viscosity γ' to depict the stability characteristics, for both the cases of stationary convection and overstability. It is found that Rayleigh number for the case of overstability and stationary convection increases with increase in rotation parametre and decreases with increase in micropolar coefficients and medium permeability, for a fixed wave number, showing thereby the stabilizing effect of rotation parametre , destabilizing effect of micropolar coefficients and medium permeability on the thermal convection of micropolar fluids.