Thermal instability analysis of convection in a horizontal nanofluid layer with rigid-rigid boundary condition

This study investigates the phenomenon of double-diffusive convection in viscoelastic nanofluids under the influence of external magnetic fields. The findings provide vital insights into how temperature gradients and magnetic forces affect fluid layer stability, demonstrating that these interactions can either enhance or delay the onset of convective instabilities. The study’s goal is to develop a robust mathematical model that captures the dynamics of these interactions and employs linear stability analysis to understand how they affect fluid dynamics. The main objective is to transform the governing partial differential equations (PDE) into a system of ordinary differential equations (ODE) by using the linear stability analysis. The Galerkin-type weighted residual method is used to derive analytical solutions that explain the stability characteristics of the system. The influence of the scaled stress relaxation parameter, scaled strain retardation parameter and Chandrasekhar number on the system’s stability was analysed with result interpretation carried out using Maple software. The stress relaxation advance the onset of oscillatory convection while the strain retardation delay the onset of oscillatory convection. The presence of magnetic field introduces a stabilizing effect on the nanofluid layer. These findings suggest that adjusting magnetic field strength and viscoelastic parameters can effectively regulate convective behavior in nanofluid systems, with potential applications in thermal management and energy-related technologies.