Numerical study of non-Newtonian fluid flow over an exponentially stretching surface: an optimal HAM validation

Present study is devoted to investigate the Casson fluid flow phenomena over an exponentially stretching surface at the heated wall. The stresses defined for Casson fluid model are reduced in the form of partial differential equations via boundary layer approximation and then converted into the system of nonlinear ODEs by means of similarity transformation. Present Casson fluid model is tackled via three different techniques: in which the numerical results are obtained through Runge–Kutta Felburge method and verified these results with the help of homotopy analysis method and modified technique known as optimal homotopy analysis method. Graphical comparisons and numerical tables are constructed to validate the results for three different techniques. The effects of each emerging parameters on velocity and temperature profiles are demonstrated through graphs. Moreover, skin friction and Nusselt number are also calculated and also provide the comparison between Newtonian fluid and non-Newtonian fluid. It is concluded that non-Newtonian fluid shows the higher skin friction coefficient as compared to Newtonian fluid, while the Nusselt number is more dominant for Newtonian case as compared to non-Newtonian case for different values of temperature exponent. Temperature exponent also play a significant role in heat transfer within the boundary layer domain.