Non-Orthogonal Stagnation Point Flow of a Nanofluid along a Moving Surface

Abstract

Non- orthogonal stagnation point flow is the generalization of Hiemanz flow. This flow contains an orthogonal stagnation-point flow to which is added a shear flow whose vorticity is fixed at infinity. Non-orthogonal stagnation point flow was first ever discussed by Stuart. It is observed that the streamlines near a stagnation point are tilted outward due to normal stress working in the stagnation point flow. Non-orthogonal stagnation point flows appeared in many physical phenomena, in industry, instrumentation, engineering, and anterior cerebral flows in humans. In the present thesis, we have to deal with the models related to non-orthogonal flows along the vertical and horizontal stretching surfaces. When it comes to nanofluids, non-orthogonal flows with nanoparticles can achieve exciting thermal conduction properties. Non-orthogonal stagnation point flows of Newtonian and non-Newtonian nanofluids are the main focus of this dissertation. This study comprises mathematical models, numerical solutions, graphical and tabular results for mass and heat transfer characteristics, and flow patterns of a nanofluid along vertical and horizontal stretching surfaces. The thermal aspects of nanoparticles are incorporated into the mathematical models by using various thermal conductivity models for nanofluids. The modified Chebyshev collocation method is used for the analysis. It is a recently developed numerical method using the Picard iterative technique and it can tackle nonlinear systems of differential equations with an accuracy of 10−7. The novelty of this study comprises mainly the application of the modified Chebyshev collocation method for solutions of highly nonlinear coupled differential equations, the mixed convection analysis, and thermal aspects of nanofluids with various effects including double diffusion, entropy generation, porous medium, and magnetic field. It is found that in the non-orthogonal flows the temperature gradient is reduced by enhancing the stretching parameter and the angle of the strike. The skin friction on the stretching surfaces is also affected by the angle of incidence.