g-jitter induced mixed convection flow of newtonian and non - newtonian nanofluid past an inclined stretching sheet

Abstract

A new class of heat transfer fluid based on nanotechnology known as nanofluid has attracted much attention of many researchers due to its potential to improve the thermal properties of conventional fluids. This new approach which significantly enhance the heat transfer is becoming popular in many industrial applications such as cooling applications, nuclear reactors, transportation industry, electronics and instrumentation and biomedical applications. In this thesis, a mathematical model of mixed convection flow of nanofluid is developed based on Tiwari and Das model to study the influence of solid nanoparticles volume fraction on the Newtonian and non- Newtonian fluid flow with heat transfer. Specifically, the flow of nanofluid past an inclined stretching sheet for viscous, second grade, Jeffrey and Casson fluids with the effect of g-jitter is considered. The velocity and temperature of the sheet are assumed to vary linearly with distance through the sheet. The governing equation which consist of coupled non-linear partial differential equations are solved numerically using an implicit finite-difference scheme known as Keller-box method. The numerical results of surface shear stress in terms of skin friction and heat transfer coefficient in terms of Nusselt number as well as the velocity and temperature profiles for amplitude of modulation, frequency of oscillation, solid nanoparticles volume fraction, inclination angle, second grade parameter, Deborah number, ratio of relaxation to retardation times and Casson parameter for assisting and opposing flows are presented graphically and analyzed in details. Numerical result shows that, the presence of solid nanoparticles in all types of fluid enhance the temperature profiles and consequently increase the heat transfer coefficients. It is also found that, the second grade parameter and Deborah number give rise to the values of the heat transfer coefficient but to a contradiction for the inclination angle, ratio of relaxation to retardation times and Casson parameter. Comparative results amongst all types of fluids also show that, Casson nanofluid has the highest heat transfer coefficient but the lowest for skin friction coefficient.