The effect of rotation on ferroconvection in the presence of couple stress forces in porous medium: a nonlinear analysis

• Published in: European physical journal plus Vol. 139; no. 3; p. 236
• Main Authors: Thakur, Akanksha, Kumar, Sunil, Devi, Reeta
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 11.03.2024; Springer Nature B.V
• Subjects: Applied and Technical Physics; Atomic; Boundary conditions; Complex Systems; Condensed Matter Physics; Drug delivery systems; Eigenvalues; Energy; Energy methods; Ferrofluids; Fluids; Linear analysis; Magnetic fields; Mathematical and Computational Physics; Molecular; Nonlinear analysis; Optical and Plasma Physics; Parameters; Physics; Physics and Astronomy; Porous materials; Porous media; Rayleigh number; Regular Article; Rotation; Stability analysis; Theoretical; Viscosity
• ISSN: 2190-5444; 2190-5444
• DOI: 10.1140/epjp/s13360-024-05048-8

This study investigates the effect of rotation on ferrofluid layer saturating a porous medium, heated from below, in the presence of couple stress forces. The analysis considers three bounding surfaces (i.e. free-free, rigid-free, and rigid-rigid) and formulates eigenvalue problems by employing linear and nonlinear analyses. Linear analysis employs normal mode analysis, while nonlinear analysis utilizes the energy method, introducing a generalized energy functional. The energy decay is established through nonlinear energy argument. The Galerkin type method is applied to solve the obtained eigenvalue problems. The findings reveal the existence of a subcritical region, which diminishes with an increase in the magnetization and medium permeability whereas, it expands with an increase in the couple stress parameter and rotation. Additionally, the effect of these parameters on the stability analysis has also been discussed. The detailed analysis of various parameters for different combinations of bounding surfaces has also been analyzed. Graphical abstract