MHD nonlinear thermally radiative Ag - TiO 2/H 2 O hybrid nanofluid flow over a stretching cylinder with Newtonian heating and activation energy

Hybrid nanofluids are significant in biomedical, industrial, transportation, as well as several engineering applications due to their high thermal conductivity and mass transfer enhancement nature in contrast to regular fluids and nanofluids. Taking this into consideration, the present problem explores the flow of hybrid nanofluid (Ag - TiO2/H2O) over a stretching cylinder subject to Newtonian heat and mass conditions. The novel aspect of the current work is to analyze the heat and mass transfer characteristics of MHD hybrid nanofluid flow on Darcy-Forchheimer porous medium in addition to activation energy, nonlinear thermal radiation, heat generation/absorption, viscous and Joulian dissipation. Further, Silver (Ag) and Titanium oxide (TiO2) are the constituent nanoparticles of the water-based hybrid nanofluid owing to their stable chemical features and extensive industrial manufacturing. By introducing suitable similarity transformations, the governing partial differential equations (PDEs) of the developed model are reduced to ordinary differential equations (ODEs), and then the numerical solution is procured with shooting technique by using MATLAB solver bvp4c. The influence of the pertinent parameters is depicted graphically and described elaborately. The analysis indicates that velocity exhibits a declining trend against the permeability and Forchheimer parameters, while the temperature profiles show opposite behavior. The radiation and conjugate heat parameters (R, gamma(1)) upgrade the heat transfer rate, while the curvature and conjugate mass parameters (alpha(c), gamma(2)) amplify the mass transfer rate. The maximum heat transfer rate of Ag - TiO2/H2O hybrid nanofluid is 2.3344 attained for gamma(1) = 0.6. The investigation demonstrates larger heat and mass transfer rates for Ag - TiO2/H2O hybrid nanofluid than Ag - H2O nanofluid. The outcomes of the present investigation have practical applications in conjugate heat transfer over fins, development of vaccines, effluent treatment plants, solar cells, heat exchangers, and many more. An excellent agreement is achieved on comparing our numerical results with the published results in the literature.