Author(s)

R. Nataraj¹, S. Bhavya²

¹Department of Mathematics, Don Bosco Institute of Technology, Bangalore, India.
²Department of Mathematics, Dr. Ambedkar Institute of Technology, Bangalore, India.

The effect of viscosity depending exponentially on temperature on the onset of penetrative ferro-thermal-convection (FTC) in a saturated horizontal porous layer in the presence of vertical magnetic field is investigated. The bounding surface of the ferrofluid layer is considered to be rigid-rigid and insulated to temperature perturbations. The resulting eigenvalue problem is solved numerically using the Galerkin technique and also analytically by a regular perturbation technique with wave number as a perturbation parameter. The analytical and numerical results are found to be concurrence. The characteristics of stability of the system are strongly dependent on the viscosity parameter B. The effect of B on the onset of ferroconvection in a porous layer is dual in nature depending on the choices of physical parameters and a sublayer starts to form at higher values of B. Whereas, increase in magnetic number M₁ and the Darcy number Da is to advance the onset of ferroconvection in a porous layer. The nonlinearity of fluid magnetization M₃ is found to have no influence on the onset of ferroconvection.

Ferroconvection, Internal Heating, Variable Viscosity, Porous Media, Galerkin Technique, Insulated Boundary

Nataraj, R. and Bhavya, S. (2019) Effect of Exponentially Temperature-Dependent Viscosity on the Onset of Penetrative Ferro-Thermal-Convection in a Saturated Porous Layer via Internal Heating. Journal of Electromagnetic Analysis and Applications, 11, 101-116. doi: 10.4236/jemaa.2019.117007.