Rabia Malik

Three-Dimensional Flow of an Oldroyd-B Nanofluid towards Stretching Surface with Heat Generation/Absorption

This article addresses the steady three-dimensional flow of an Oldroyd-B nanofluid over a bidirectional stretching surface with heat generation/absorption effects. Suitable similarity transformations are employed to reduce the governing partial differential equations into coupled nonlinear ordinary differential equations. These nonlinear ordinary differential equations are then solved analytically by using the homotpy analysis method (HAM). Graphically results are presented and discussed for various parameters, namely, Deborah numbers and , heat generation/absorption parameter Prandtl parameter , Brownian motion parameters, thermophoresis parameter and Lewis number . We have seen that the increasing values of the Brownian motion parameter and thermophoresis parameter leads to an increase in the temperature field and thermal boundary layer thickness while the opposite behavior is observed for concentration field and concentration boundary layer thickness. To see the validity of the present work, the numerical results are compared with the analytical solutions obtained by Homotopy analysis method and noted an excellent agreement for the limiting cases.

Flow and heat transfer in Sisko fluid with convective boundary condition.

In this article, we have studied the flow and heat transfer in Sisko fluid with convective boundary condition over a non-isothermal stretching sheet. The flow is influenced by non-linearly stretching sheet in the presence of a uniform transverse magnetic field. The partial differential equations governing the problem have been reduced by similarity transformations into the ordinary differential equations. The transformed coupled ordinary differential equations are then solved analytically by using the homotopy analysis method (HAM) and numerically by the shooting method. Effects of different parameters like power-law index , magnetic parameter , stretching parameter , generalized Prandtl number Pr and generalized Biot number are presented graphically. It is found that temperature profile increases with the increasing value of and whereas it decreases for . Numerical values of the skin-friction coefficient and local Nusselt number are tabulated at various physical situations. In addition, a comparison between the HAM and exact solutions is also made as a special case and excellent agreement between results enhance a confidence in the HAM results.

Flow and Heat Transfer to Sisko Nanofluid over a Nonlinear Stretching Sheet

The two-dimensional boundary layer flow and heat transfer to Sisko nanofluid over a non-linearly stretching sheet is scrutinized in the concerned study. Our nanofluid model incorporates the influences of the thermophoresis and Brownian motion. The convective boundary conditions are taken into account. Implementation of suitable transformations agreeing with the boundary conditions result in reduction of the governing equations of motion, energy and concentration into non-linear ordinary differential equations. These coupled non-linear ordinary differential equations are solved analytically by using the homotopy analysis method (HAM) and numerically by the shooting technique. The effects of the thermophoresis and Brownian motion parameters on the temperature and concentration fields are analyzed and graphically presented. The secured results make it clear that the temperature distribution is an increasing function of the thermophoresis and Brownian motion parameters and concentration distribution increases with the thermophoresis parameter but decreases with the Brownian motion parameter. To see the validity of the present work, we made a comparison with the numerical results as well as previously published work with an outstanding compatibility.

Mixed convective heat transfer to Sisko fluid over a radially stretching sheet in the presence of convective boundary conditions

In this article, the mixed convective heat transfer to Sisko fluid over a radially stretching surface in the presence of convective boundary conditions is investigated. The viscous dissipation and thermal radiation effects are also taken into account. The suitable transformations are applied to convert the governing partial differential equations into a set of nonlinear coupled ordinary differential equations. The analytical solution of the governing problem is obtained by using the homotopy analysis method (HAM). Additionally, these analytical results are compared with the numerical results obtained by the shooting technique. The obtained results for the velocity and temperature are analyzed graphically for several physical parameters for the assisting and opposing flows. It is found that the effect of buoyancy parameter is more prominent in case of the assisting flow as compared to the opposing flow. Further, in tabular form the numerical values are given for the local skin friction coefficient and local Nusselt number. A remarkable agreement is noticed by comparing the present results with the results reported in the literature as a special case.

Forced convective heat transfer to Sisko fluid flow past a stretching cylinder

The numerical solutions are investigated for the forced convection heat transfer resulting from MHD flow of an electrically conducting Sisko fluid over an impermeable continuously stretching cylinder in its axial direction. The convective boundary conditions along with the viscous dissipation are considered. The governing equations are transformed using the local-similarity transforms and then solved numerically by using shooting technique. It is found from the analysis that the temperature is smaller in case of flow over a flat plate than that of cylinder. Further, influence of the pertinent parameters is more prominent for the shear thinning fluid compared to the shear thickening fluid. The validation of present numerical results is affirmed by presenting a comparison with the series solutions obtained by the homotopy analysis method as well as some existing literature.

Nonlinear radiative heat transfer to stagnation-point flow of Sisko fluid past a stretching cylinder

In the present paper, we endeavor to perform a numerical analysis in connection with the nonlinear radiative stagnation-point flow and heat transfer to Sisko fluid past a stretching cylinder in the presence of convective boundary conditions. The influence of thermal radiation using nonlinear Rosseland approximation is explored. The numerical solutions of transformed governing equations are calculated through forth order Runge-Kutta method using shooting technique. With the help of graphs and tables, the influence of non-dimensional parameters on velocity and temperature along with the local skin friction and Nusselt number is discussed. The results reveal that the temperature increases however, heat transfer from the surface of cylinder decreases with the increasing values of thermal radiation and temperature ratio parameters. Moreover, the authenticity of numerical solutions is validated by finding their good agreement with the HAM solutions.

ANALYTIC SOLUTIONS FOR MHD FLOWS OF AN OLDROYD-B FLUID BETWEEN TWO SIDEWALLS PERPENDICULAR TO THE PLATE

This study is concerned with analytic solutions of some magnetohydrodynamic (MHD) flows of an Oldroyd-B fluid. The fluid is assumed to be electrically conducting in the presence of a uniform magnetic field and occupies the space over a flat plate between two sidewalls perpendicular to the plate. The governing equation of motion is treated analytically, yielding the derivation of exact solutions under integral and series form. By assigning numerical values to various parameters, the integrals encountered are evaluated numerically. In the absence of sidewalls, all solutions that have been obtained reduce to those corresponding to the motion over an infinite plate. The impacts of several quantities are investigated on the resulting velocity field and the tangential stress at the bottom wall.