Effect of Exponentially Temperature-Dependent Viscosity on the Onset of Penetrative Ferro-Thermal-Convection in a Saturated Porous Layer via Internal Heating

• 作者: R. Nataraj S. Bhavya
• 来源期刊: 电磁分析与应用期刊(英文)
• 学科: 数学
• 关键词: Ferroconvection Internal HEATING Variable VISCOSITY POROUS Media GALERKIN Technique Insulated BOUNDARY
• 年，卷（期）: 2019,（7）
• 页码范围: 101-116
• 页数: 16页
• 分类号: O1

摘要

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.