Enhancing heat transfer efficiency through nanofluid applications

Abstract

The present thesis is related to theoretical study of various nanofluid flows in different conditions. The formulation of mathematical model must warrant two important aspects: (i) the model should represent a real-world problem and possible industrial applications (ii) the mathematical model so formulated must have solutions either analytical or numerical or both. The motivation of each flow model has been spelt out clearly with an emphasis to the supplementary and complementary aspects of earlier studies so that the generality and validation can be accomplished. newlineThe present topic mostly related to the flow through two parallel plates as well as stretching/shrinking of the sheets. It has wide range of applications in modern technology. Moreover, governing equations of related model possess similarity solution as suggested by L. J. Crane to solve a steady two-dimensional incompressible boundary layer flow caused by the stretching of a sheet which moves in its own plane. The study of Newtonian fluid flows over a stretching surface has important application in polymer industry. For instance, a number of technical processes relating to polymers involve the cooling of continuous strips/filaments extruded from a die by drawing them through a stagnant fluid with controlled cooling system and in the process of drawing, these strips are sometimes stretched. The quality of the final product depends to a large extent on the rate of heat transfer at the stretching surface. newlineThe governing equations characterizing the flow heat and mass transfer phenomena are solved numerically as well as analytically. The analytical method is based upon homotopy perturbation method, standard differential methods, etc. The coupled non-linear partial differential equations, governing the flow-model with appropriate boundary conditions are reduced to ordinary differential equations with suitable similarity transformations. Then Runge-Kutta fourth order method with shooting technique has been applied to solve the equations.