2024/04/12 by Snehashish Sarkar, Sarkar, Snehashish, Sutapa Mandal +3
Biochemistry, Genetics and Molecular Biology · Engineering · Physics and Astronomy · #Chaotic Dynamics (nlin.CD) #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Fluid Dynamics and Turbulent Flows #Geomagnetism and Paleomagnetism Studies #Pattern Formation and Solitons (nlin.PS) #Solar and Space Plasma Dynamics
paper · pdf · doi:10.48550/arxiv.2404.08481
openalex publication_date 2024/04/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate the instabilities and associated bifurcation structure near the onset of rotating magnetoconvection of low Prandtl number fluids by performing three dimensional direct numerical simulations. Previous studies considered zero magnetic Prandtl number (Pm) limit for the investigation of bifurcation structure near the onset of convection. Here we numerically investigate the effect of Pm on the bifurcation structure. The classical Rayleigh-Bénard convection setup in the presence of horizontal magnetic field and rotation about the vertical axis are considered for the study. The control parameters, including the Taylor number (Ta), Chandrasekhar number (Q), reduced Rayleigh number (r), and magnetic Prandtl number (Pm) are varied in the ranges 0 < Ta≤ 500, 0 < Q≤ 1000, 0.8≤ r ≤ 2 and 0 < Pm < 1 by considering Prandtl numbers Pr= 0.025 and 0.1. The investigation reveals the presence of supercritical, subcritical and hybrid transitions to convection. These transitions leads to infinitesimal and finite amplitude fluid patterns at the onset of convection. The finite amplitude solutions can be both stationary and time dependent. The bifurcation structures associated with these flow patterns at the onset are studied in detail. For very small Pm, the bifurcation structure is found to be qualitatively similar to the ones observed in the Pm→ 0 limit. However, as Pm is increased, several new solutions appear at the onset and the resulting bifurcation structures are greatly modified.