An innovative tri-hybrid blood-based model with couple stresses for drug delivery applications in convergent-divergent channels

This research aims to investigate the Jeffery–Hamel model for flow and thermal behavior of ternary nanofluid flow through converging/diverging channels with stretchable/shrinkable walls. Silver (Ag), titanium dioxide [Formula: see text], and aluminum oxide [Formula: see text]. Solid nanoparticles are preferred for drug delivery applications, with blood serving as the base fluid. A radial magnetic field influences the blood flow and is primarily analyzed through the couple stresses. Consequently, in the current investigation, the addition of a magnetic field and couple stress, which capture microstructural behavior, provides an in-depth comprehension of flow dynamics in these channels. The Darcy–Forchheimer porous medium is employed to examine the tri-hybrid nanofluid’s motion and thermal characteristics. Additionally, the drag forces applied by the channel increase with greater porosity parameters and inertia coefficients. The coupled system of equations, describing the physical problem, is converted into ordinary differential equations through appropriate transformations. The momentum and energy equations are solved numerically using the Simpson rule after reducing their order, while the SOR method is applied to solve the linear equations following domain discretization with the FDM. Results indicate that a higher couple stress parameter enhances fluid mobility, increasing the velocity profile, while the Forchheimer parameter increases resistance in convergent channels and moderates deceleration in divergent channels, affecting velocity accordingly. Applied magnetic forces are found to effectively control fluid motion and enhance the temperature profile through Joule heating. Reynolds number boosts velocity in convergent channels while reducing it in divergent ones, with opposite effects on the temperature profile. An increase in the Radiation parameter raises the temperature in convergent channels but lowers it in divergent channels, while a higher Eckert number elevates the temperature in both channels due to viscous dissipation. Therefore, these new insights into heat transfer would be beneficial for the problems of energy storage in the modern technological world.