Effects of pressure stress work and viscous dissipation in natural convection flows from a horizontal circular cylinde

Abstract

In this thesis under the title, “Effects of pressure stress work and viscous dissipation in natural convection flows from a horizontal circular cylinder”, we have studied two problems namely effects of pressure stress work and viscous dissipation in natural convection flows from a horizontal circular cylinder and joule heating effects on magnetohydrodynamic (MHD) natural convection flows in presence of pressure stress work and viscous dissipation from a horizontal circular cylinder which belongs to two different chapters. In chapter two, the steady laminar natural convection flow along the surface of a uniformly heated horizontal circular cylinder, taking into account the effects of viscous dissipation and pressure stress work, has been studied. The results have been obtained by transforming the governing boundary layer equations into a system of non-dimensional equations and by applying implicit finite difference method together with Newton’s linearization approximation. Numerical results for different values of the viscous dissipation parameter, pressure stress work parameter, and Prandtl number have been obtained. The velocity profiles, temperature distributions, skin friction co-efficient and the rate of heat transfer have been presented graphically for the effects of the aforementioned parameters. In chapter three, the joule heating effects on MHD natural convection flow from a horizontal circular cylinder in the presence of pressure stress work and viscous dissipation has been investigated. The governing boundary layer equations are first transformed into a non-dimensional form and the resulting nonlinear systems of partial differential equations are then solved numerically using finite-difference method. The numerical results of the surface shear stress in terms of skin friction coefficient and the rate of heat transfer, velocity as well as temperature profiles are shown graphically and discussed for a selection of parameters set consisting of joule heating parameter J, magnetic parameter M and the Prandlt number Pr.