Nonlinear stability and dynamics of RayleighBard convection in variable viscosity ferromagnetic liquids
- Title
- Nonlinear stability and dynamics of RayleighBard convection in variable viscosity ferromagnetic liquids
- Creator
- Jayalatha, G.; Prakash, R.; Siddheshwar, P.G.; Sekhar, G.N.
- Description
- RayleighBard convection in ferromagnetic liquids provides a fundamental framework for understanding magneto-thermal transport in systems where buoyancy, magnetic forces and material properties interact. Most nonlinear studies of ferroconvection, however, assume constant viscosity, even though in practical ferrofluids viscosity may vary with temperature and be influenced by an applied magnetic field. In this work, we examine the stability and nonlinear dynamics of a Newtonian ferromagnetic liquid confined between rigid isothermal boundaries and subjected to a uniform vertical magnetic field, while explicitly accounting for viscosity variations arising from thermal and magnetic effects. Linear stability analysis is carried out using a truncated Galerkin approach, leading to an analytical expression for the stationary critical Rayleigh number that incorporates the viscosity-dependence parameter and magnetic numbers. To investigate post-onset behavior, a generalized Lorenz-type system is derived through a minimal FourierGalerkin truncation, allowing steady, oscillatory and irregular convection states to be explored within a low-dimensional nonlinear framework. Heat transport is interpreted through a Nusselt number formulation expressed in terms of the reduced system variables, with time-averaged values used in non-steady regimes. The model recovers established constant-viscosity ferroconvection results in the appropriate limiting case and demonstrates how viscosity variation modifies stability thresholds, amplitude saturation and convective transport trends. The present formulation provides a compact theoretical basis for assessing the combined influence of thermorheological and magnetorheological effects on convection dynamics in ferrofluid layers relevant to magnetic thermal control applications. The Author(s), under exclusive licence to SocietItaliana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2026.
- Source
- European Physical Journal Plus;Volume;141;Issue;3;Article No.;289;
- Date
- 01-01-2026
- Publisher
- Springer Science and Business Media Deutschland GmbH
- Coverage
- Jayalatha G., Department of Mathematics, RV College of Engineering, Karnataka, Bengaluru, 560059, India; Prakash R., Department of Mathematics, RV College of Engineering, Karnataka, Bengaluru, 560059, India; Siddheshwar P.G., Centre for Mathematical Needs, Christ University, Karnataka, Bengaluru, 560029, India; Sekhar G.N., Department of Mathematics, BMS College of Engineering, Karnataka, Bengaluru, 560019, India
- Rights
- Restricted Access; Hardcopy may be available in the library
- Relation
- ISSN: 21905444;
- Format
- online
- Language
- English
- Type
- Article
Collection
Citation
Jayalatha, G.; Prakash, R.; Siddheshwar, P.G.; Sekhar, G.N., “Nonlinear stability and dynamics of RayleighBard convection in variable viscosity ferromagnetic liquids,” CHRIST (Deemed To Be University) Institutional Repository, accessed June 19, 2026, https://archives.christuniversity.in/items/show/23008.