Modeling and improving blood flow dynamics for industrial applications using a variable property second grade nanofluid with convective boundary effects

This study presents a numerical examination of a steady, two-dimensional second-grade nanofluid flowing due to a stretching sheet with convective boundary conditions. The model incorporates temperature-dependent thermophysical properties, featuring an exponential decay of viscosity and density alongside a linear variation in thermal conductivity. To ensure a physically consistent solution for the resulting fourth-order momentum equation, an augmented boundary condition and a judiciously selected sign for the normal stress modulus are implemented. The governing nonlinear partial differential equations are transformed into a coupled system of ordinary differential equations via similarity variables and solved computationally using the Runge Kutta shooting technique. Graphical and tabular results elucidate the impact of pivotal dimensionless parameters on the flow, thermal, and concentration fields, as well as on engineering quantities of interest. A key finding affirms the unidirectional transfer of heat from the sheet to the nanofluid, offering new insights into the behavior of second-grade nanofluids with variable properties. A principal finding of this investigation is that increasing viscosity, density variation, suction, and thermophoretic transport collectively modify the boundary-layer behavior by suppressing the near-wall fluid motion, enhancing thermal and concentration distributions, and significantly influencing the skin-friction characteristics. The outcomes of this study are validated through comparison with available peer-reviewed results, showing good agreement that supports the reliability of the numerical model and the consistency of the obtained solutions.