Numerical analysis of dissipative peristaltic nanofluid flow through a chemically reactive non-uniform flexible channel with double-diffusive convection

Peristaltic transport of chemically reactive nanofluids exhibiting double-diffusive behaviour has attracted growing attention due to its relevance in microfluidic engineering, biomedical devices and environmentally driven transport processes. Motivated by these applications, the present study formulates a comprehensive mathematical model to examine peristaltically driven flow of a double-diffusive Ree–Eyring nanofluid through a slanted, symmetric and geometrically non-uniform microchannel filled with a porous medium. The model incorporates activation energy effects together with coupled thermal and solutal convection, while accounting for shear-dependent rheology through the Ree–Eyring constitutive relation. The resulting system of boundary value equations is solved numerically using the Lobatto IIIA approach through the bvp5c solver implemented in MATLAB. Parametric investigations reveal the influence of governing parameters on velocity, shear stress, temperature distribution, nanoparticle and solute concentrations, heat transfer rate and streamline patterns. The results show that increasing the solutal Grashof number and Ree-Eyring parameter suppresses fluid velocity, while thermal gradients are significantly intensified by internal heat generation and thermophoretic effects. Notably, enhancing the Brownian motion parameter from 0.2 to 0.3 leads to a 26.45% reduction in wall mass transfer rate. These findings provide new physical insight into peristaltic transport mechanisms in bioadaptive and environmentally responsive fluid systems.