Abstract
The current study investigates the flow of viscous nanofluids over the stretching surface with variable thickness in the presence of heterogeneous and homogeneous reactions. Comparison is made for water-based nanofluids with copper (Cu), silver (Ag), copper oxide (CuO), aluminum oxide (Al2O3), and titanium oxide (TiO2) as nanoparticles. The heat transfer phenomenon is characterized by nonlinear thermal radiation. The formulation of the model consists of partial differential equations with convective boundary conditions, which are converted into ordinary differential equations with the help of boundary layer approximation. The convergent series solution is computed with the help of an efficient analytical method, namely the Optimal Homotopy technique. For the validation of the suggested approach, the convergence of the obtained results is illustrated for different values of involved parameters. Moreover, residual errors for the varied number of terms in the derived series solution are displayed graphically. To validate the accuracy of the present results, a comparison with previously published results is presented. The influence of various variables on the velocity profile, the distribution profiles of temperature, and concentration is graphically discussed. Heat transfer rate (or local Nusselt number) and skin friction coefficient are estimated through the Tables. It is observed that temperature rises for higher radiation parameter and the temperature of aluminum oxide nanofluid is more because of its higher thermal conductivity as compared to other four nanoparticles. The study also reveals that with an improvement in the volume fraction of nanoparticles, the degree of the heat transfer rate and the coefficient of skin friction also increases.