Mathematical Modeling and Numerical Simulation of ",Sisko Fluid Flow over a Stretching Surface

Abstract

Flow behavior of several complex fluids is characterized by viscosity dependency on the rate of deformation. Such type of viscosity dependency is one of the basic category of non-Newtonian fluids rather than Newtonian fluids. Appropriate prediction ofrheological characteristics such as shear stress and shear strain are forcible in useful applications. For instance, protein formulations/injections, inkjet printing and food/beverage manufacturing and so forth. Such engineering importance insured that the modeling and in-depth study of non-Newtonian fluids is one of the need of the day. The contributions in this thesis push further the mathematical modeling and analysis of generalized Newtonian Sisko fluid which is declared a subclass of non-Newtonian fluids. This thesis consists of two main parts: One presenting mathematical modeling of Sisko fluid and the other one describing and analyzing the results for flow, heat and mass transfer. In current t hesis, we present a contribution to the mathematical formulations for 2D as well as 3D steady and unsteady Sisko fluid flows with heat and mass transfer. The modeled governing PDEs are transformed through some dimensionless variables into ordinary differential equations (ODEs). The whole computational work is carried out with the help of well known numerical approaches namely RKF with shooting technique, built in boundary value problem (BVP) solver bvp4c and Richardson extrapolation with built in command BVP traprich. A meaningful physical interpretation in the form of computational analysis is performed to characterize the behavior of velocity, pressure, temperature and concentration of Sisko fluid. The major observations associated to the flows of pseudo-plastic as well as dilatant fluids which are the sub cases of Sisko fluid are highlighted with the important enhancement behavior of the velocity and associated momentum boundary layer thiclmess(MBLT) with higher material and curvature parameters. This study is more important in the context where the magnitude of pressure inside the boundary layer(BL) is observed in the growing conduct for weaker values of the curvature parameter and outside of the BL the magnitude becomes zero. However, this study reported a very significant decreasxv ing trend in the temperature and concentration as well as related thermal boundary layer thickness(TBLT) and concentration boundary layer thickness(CBLT) with enhancing material and curvature parameters. Ultimately, the research work presented in this thesis will aid in the understanding and analyzing the diverse rheological characteristics of the generalized Newtonian Sisko fluid.