Ferro-thermal-convection in a micropolar ferrofluid saturated porous layer and submitted to a Robin thermal boundary condition

The theoretical analysis is carried out for the problem of ferro-thermal-convection (FTC) onset in a micropolar ferrofluid-saturated porous layer submitted to a Robin type of thermal boundary condition. The boundaries are considered to be lower-rigid at isothermal, while upper-rigid at Robin-type of thermal boundary condition. The higher order Galerkin-type of weighted residual method is used to obtain the eigenvalue. The behavior of the critical stability parameters is discussed in various dimensionless physical parameters akin to the magnetic number, non-linearity of magnetization parameter, Biot number, coupling parameter, Darcy number, spin diffusion parameter and heat conduction of micropolar parameter. The result shows that the onset of thermomagnetic convection is postponed with an increase in N1, Bi and N5 but convection is accelerated with an increase in M1, M3 and N3. Furthermore, some known results are compared with existing results.