Impact of Cattaneo-Christov Heat Flux in Newtonian and Non-Newtonian Nanofluid Flows

Abstract

Analysis of heat and mass transfer of Newtonian and non-Newtonian nanofluid flows in varied complex geometries emphasizing Cattaneo-Christov heat flux is elucidated in this thesis. This thesis focuses on the problems that concentrate on the modified Fourier law which is the upgraded form of the classical Fourier law under various scenarios and geometries including disk, cylinder, and sheets extended in two and three dimensions. The topic of fluid flows due to nanofluid has also been the epicenter of discussion owing to its widespread industrial and mechanical applications in biomedical such as cancer therapy. Measuring heat transfer can be useful in assessing the amount of heat transported through a wall or a nervous system, or the quantity of gamma-ray or solar radiant energy delivered to a specific area. Using a heat flux detector under natural convection conditions could be effective for lower-powered devices. Nanofluid is used to cool microchips in computers, radiators in automobiles, and energy storage systems. The envisioned flow models encompass the effects of variable thermal conductivity and diffusion coefficients, heat generation/absorption, non-uniform heat source-sink, viscous dissipation, velocity, and thermal slips, convective boundary conditions, homogenous-heterogenous reactions with surface catalyzed reaction, and gyrotactic microorganism in different geometries. The renowned hybrid nanofluid models namely Yamada-Ota, Hamilton-Crosser, and Xue following Tawari and Das flow pattern are considered. The geometries considered in this thesis include two and three-dimensional flows, flow over a rotating disk, a cylinder, and in a channel. The physical flow model, which takes the form of differential equations, is governed by boundary layer approximations. For various values of the emergent parameters, physical quantities like velocities, temperature, concentration, Sherwood and Nusselt numbers, and skin friction coefficients are computed numerically and examined in depth. A MATLAB built-in function bvp4c is used to draw the association of varied profiles with parameters through graphical illustrations and to validate the findings by comparing them with earlier published works. An excellent correlation between the results is obtained. The key finding of this thesis leads to conclude that the results of hybrid nanofluid are dominant as compared to nanofluid flow and similarly Yamada-Ota model achieves better results than the Xue model. The velocity and temperature of dust particles increase as the fluid-particle interaction parameter increases. The greater thermal relaxation time parameter decreases the fluid temperature. The significance of our study is the that heat transfer phenomenon is applicable in various physical situations and manufacturing processes are designed to maximize efficiency.