Bioconvective Chemically Reactive Radiative Squeezing Flow of a Casson Hybrid Nanofluid Between Two Parallel Plates Under Variable Viscosity

ABSTRACT Hybrid nanofluids, known for their superior thermal and electrical conductivity, have demonstrated remarkable potential in enhancing the heat transfer capability of conventional base fluids. This study analyzes the effects of viscous dissipation and heat radiation on two‐dimensional unsteady incompressible squeezing flow transporting hybrid nanoparticles between two parallel plates with variable viscosity. By incorporating the appropriate similarity transformations, the governing partial differential equations are converted into a system of coupled nonlinear ordinary differential equations. The mathematical simulation is performed using the shooting technique combined with the fourth‐order Runge–Kutta method. As the squeezing intensifies, the Nusselt number at the lower plate decreases by nearly 30%, while that at the upper plate increases by about 35%, reducing the interplate heat transfer difference from 54% to nearly 13%. The outcomes of this research are beneficial for applications in microfluidic cooling, lubrication systems, and biomedical heat regulation.