Multiple solutions and temporal stability for ternary hybrid nanofluid flow between non-parallel plates with entropy generation analysis

The present study employs the predictor homotopy analysis method (PHAM) to investigate the behaviour of incompressible, steady ternary hybrid nanofluid flow through a converging or diverging channel (non-parallel plates). The study aims to capture multiple solutions containing various shapes of nanoparticles, including spherical (Alumina [Al2O3]), platelet-like (Graphene [Gr]), and cylindrical (carbon nanotube [CNT]). The impact of physical parameters (such as Reynolds number, nanoparticle volume fractions, and heat source/sink parameters) on critical physical quantities has been studied. The study also considers the backflow regime, which results in multiple flow patterns in converging plates but is absent in diverging ones. Additionally, the article deals with a second-law analysis assuming several parameters, and PHAM is used to investigate the temporal stability of both solution branches. The results show the existence of a stable branch with positive eigenvalues. Stability analysis confirms that the upper branch of the solution is physically significant. The study contributes to understanding the behaviour of nanofluid flow and its applications in various fields.