Thermal instability in Rivlin-Ericksen elastico-viscous fluid in the presence of finite Larmor radius and variable gravity in porous medium

The effect of the finite Larmor radius (FLR) and variable gravity force in the thermal instability of Rivlin-Ericksen elastico-viscous fluid in porous medium is considered. It is found that the presence of magnetic field (hen ce of FLR) and visco-elasticity introduces oscillatory modes, when gravity is increasing upward but oscillatory modes are non-existent in their absenc e. It is also found that system is stable, when gravity decreases upward. W hen instability sets in as stationary convection finite Larmor radius have stabilizing effect whereas magnetic field and medium permeability has stabi lizing or destabilizing effect under certain conditions. The sufficient con ditions for the non-existence of overstability are also found.