Double-diffusive stagnation point flow over a vertical surface with thermal radiation: Assisting and opposing flows

In numerous industrial procedures, the main concern of design engineers is ensuring adequate heat and mass transfer, such as in the heating and cooling practices of solar water heaters, geothermal systems, extrusion of metal, insulation of buildings, electronics, turbines, aerodynamics, electronics, paper manufacturing, and glass fiber production. The unsteady double-diffusive mixed convection flow of boundary layer nanofluids above a vertical region near stagnation point flow is developed and examined here. The Brownian motion and thermophoresis effects are incorporated by using Buongiorno's model. In the thermal energy equations, diffusion of regular and cross types is also used. By the use of the local similarity method along with suitable similarity transformations, nonlinear unsteady partial differential equations are converted to nonlinear ordinary differential equations and are numerically solved by the Keller-Box method. The investigation expresses that these profiles of solute concentration and nanoparticle concentration, temperature, and velocity in their boundary layers, respectively, depending on several parameters. A graphic analysis of all these parameters' possessions on nature's boundary layers is depicted. The highest rate of heat transfer is obtained with negligible thermophoresis effect. Furthermore, it is perceived that an increase in Nc and Nt results in a reduction in the reduced Sherwood number of nanoparticles, whereas addition results in an increase in the Nb number. There is a reverse effect on the temperature field and layer thickness for heat generation. In the wake of the above-mentioned potential applications, the current study of fluid flow has been found to be very interesting and innovative in the analysis of the influence of Brownian motion and thermophoresis effects near stagnation point flow, which will further make revolutions in industrial fields. Moreover, Buongiorno's model predicts the characteristics of double-diffusive fluids in enhancing heat transfers. This investigation has been established as a result of the numerous industrial applications mentioned above.

Automated summary

In various industrial processes, design engineers focus on ensuring efficient heat and mass transfer, such as in heating and cooling practices of solar water heaters, geothermal systems, metal extrusion, building insulation, electronics, turbines, aerodynamics, paper manufacturing, and glass fiber production. This study investigates the unsteady double-diffusive mixed convection flow of boundary layer nanofluids near a stagnation point, incorporating the effects of Brownian motion and thermophoresis using Buongiorno's model. By employing the local similarity method and suitable transformations, the non-linear partial differential equations are transformed into non-linear ordinary differential equations and solved numerically using the Keller-Box method. The investigation reveals the dependence of solute and nanoparticle concentrations, temperature, and velocity profiles on various parameters, with graphical analysis demonstrating their impact on the boundary layer characteristics. The study highlights the potential applications and innovations in industrial fields resulting from the analysis of Brownian motion and thermophoresis effects near the stagnation point in fluid flow, while also emphasizing the relevance of Buongiorno's model for enhancing heat transfers in double-diffusive fluids.