S. A. Shehzad

Mixed Convection Stagnation Point Flow of Casson Fluid with Convective Boundary Conditions

The mixed convection stagnation-point flow of an incompressible non-Newtonian fluid over a stretching sheet under convective boundary conditions is investigated. Mathematical formulation is presented for a Casson fluid. The resulting partial differential equations are converted into the ordinary differential equations by the suitable transformations. The velocity and temperature profiles are computed by employing the homotopy analysis method. The plotted graphs illustrate the flow and heat transfer characteristics and their dependence upon the embedded parameters. Numerical values of skin-friction coefficient and Nusselt number are given and examined. Comparison of the present results with the existing solution is also given.

Effects of mass transfer on MHD flow of casson fluid with chemical reaction and suction

Effect of mass transfer in the magnetohydrodynamic flow of a Casson fluid over a porous stretching sheet is addressed in the presence of a chemical reaction. A series solution for the resulting nonlinear flow is computed. The skin friction coefficient and local Sherwood number are analyzed through numerical values for various parameters of interest. The velocity and concentration fields are illustrated for several pertinent flow parameters. We observed that the Casson parameter and Hartman number have similar effects on the velocity in a qualitative sense. We further analyzed that the concentration profile decreases rapidly in comparison to the fluid velocity when we increased the values of the suction parameter.

Nonlinear thermal radiation in three-dimensional flow of Jeffrey nanofluid

Three-dimensional flow of Jeffrey fluid is modeled.Radiative flow is taken into account.Thermophoresis and Brownian motion effects are incorporated.Series solutions are developed to analyze the results.Values of local Nusselt and Sherwood numbers are computed and discussed. This article explores the characteristics of thermophoresis and Brownian motion in magnetohydrodynamic three-dimensional flow of nano Jeffrey fluid. Flow analysis is modeled in the presence of thermal radiation. The resulting stretched flow problems have been solved for the velocity, temperature and concentration. The constructed expressions depend upon ratio of relaxation to retardation times, Deborah number, magnetic parameter, ratio of stretching rates, Lewis number, Prandtl number, radiation parameter, thermophoresis and Brownian motion parameters. Plots are presented and analyzed specifically for the temperature and nanoparticle concentration profiles. Numerical computations are performed for local Nusselt and Sherwood numbers. Impact reflecting the contributions of various embedded on the local Nusselt and Sherwood numbers is point out. It is observed that temperature and nanoparticle concentration profiles are decreased with an increase in Deborah number. An increase in thermophoresis parameter shows rise to the temperature and nanoparticle concentration fields. It is also seen that temperature and nanoparticle concentration profiles are quite opposite when Brownian motion parameter is increased.

Mixed convection flow of viscoelastic nanofluid by a cylinder with variable thermal conductivity and heat source/sink

Purpose – The purpose of this paper is to examine the effects of variable thermal conductivity in mixed convection flow of viscoelastic nanofluid due to a stretching cylinder with heat source/sink. Design/methodology/approach – The authors have computed the existence of the solution for Walter’s B and second grade fluids corresponding to Pr=0.5 and Pr=1.5. Skin-friction coefficient, local Nusselt and Sherwood numbers are computed numerically for different values of emerging parameters. Findings – A comparative study with the existing solutions in a limiting sense is made and analyzed. The authors found that the dimensionless velocity filed and momentum boundary layer thickness are increased when the values of viscoelastic parameter increase. The present non-Newtonian fluid flow reduces to the viscous flow in the absence of viscoelastic parameter. The larger values of viscoelastic parameter corresponds to the higher values of local Nusselt and Sherwood numbers. Originality/value – No such analysis exists i...

Nonlinear thermal radiation and cubic autocatalysis chemical reaction effects on the flow of stretched nanofluid under rotational oscillations

Combined effects of nonlinear thermal radiation and cubic autocatalysis chemical reaction on the three dimensional flow of stretched nanofluid along a rotating sheet have been investigated in this paper. The flow field is assumed to be suspended with magnetic iron oxide nanoparticles (IONPs). Hamilton-Crosser model is applied to measure effective thermal conductivity of nanofluid. Rosseland approximation is employed to obtain the nonlinear radiative heat flux. For novelty and practical point of view, influence of fluctuating surface velocity and periodic surface temperature constraints are incorporated into the governing equations which in turn are made dimension free by employing suitable transformations. For numerical solutions, an explicit finite difference scheme has been proposed under the restrictions of derived stability conditions.

MHD Mixed Convective Peristaltic Motion of Nanofluid with Joule Heating and Thermophoresis Effects

The primary objective of present investigation is to introduce the novel aspect of thermophoresis in the mixed convective peristaltic transport of viscous nanofluid. Viscous dissipation and Joule heating are also taken into account. Problem is modeled using the lubrication approach. Resulting system of equations is solved numerically. Effects of sundry parameters on the velocity, temperature, concentration of nanoparticles and heat and mass transfer rates at the wall are studied through graphs. It is noted that the concentration of nanoparticles near the boundaries is enhanced for larger thermophoresis parameter. However reverse situation is observed for an increase in the value of Brownian motion parameter. Further, the mass transfer rate at the wall significantly decreases when Brownian motion parameter is assigned higher values.

MHD stagnation point flow of Jeffrey fluid by a radially stretching surface with viscous dissipation and Joule heating

Abstract The steady stagnation-point flow of an electrically conducting fluid due to convectively heated stretched disk in the radial direction is considered. Effects of viscous dissipation and Joule heating are present. Mathematical modelling is based upon constitutive relations of Jeffrey fluid. The governing partial differential equations are first transformed into the coupled system of ordinary differential equations and then solved for the convergent series solutions. Numerical values of skin friction coefficient and local Nusselt number are also computed and analysed.

Influence of heat and mass flux conditions in hydromagnetic flow of Jeffrey nanofluid

This article explores the hydromagnetic steady flow of Jeffrey fluid in the presence of thermal radiation. The chosen nanofluid model takes into account the Brownian motion and thermophoresis effects. Flow and heat transfer characteristics are determined by a stretching surface with flux conditions. The nonlinear boundary layer flow through partial differential systems is converted into the ordinary differential systems. The resulting reduced systems are computed for the convergent solutions of velocity, temperature and nanoparticle concentration. Graphs of dimensionless temperature and nanoparticle concentration profiles are presented for different values of emerging parameters. Skin-friction coefficient are computed and analyzed in both hydrodynamic and hydromagnetic flow situations.

Thermal and concentration stratifications effects in radiative flow of Jeffrey fluid over a stretching sheet.

In this article we investigate the heat and mass transfer analysis in mixed convective radiative flow of Jeffrey fluid over a moving surface. The effects of thermal and concentration stratifications are also taken into consideration. Rosselands approximations are utilized for thermal radiation. The nonlinear boundary layer partial differential equations are converted into nonlinear ordinary differential equations via suitable dimensionless variables. The solutions of nonlinear ordinary differential equations are developed by homotopic procedure. Convergence of homotopic solutions is examined graphically and numerically. Graphical results of dimensionless velocity, temperature and concentration are presented and discussed in detail. Values of the skin-friction coefficient, the local Nusselt and the local Sherwood numbers are analyzed numerically. Temperature and concentration profiles are decreased when the values of thermal and concentration stratifications parameters increase. Larger values of radiation parameter lead to the higher temperature and thicker thermal boundary layer thickness.

Hydromagnetic steady flow of Maxwell fluid over a bidirectional stretching surface with prescribed surface temperature and prescribed surface heat flux.

This paper investigates the steady hydromagnetic three-dimensional boundary layer flow of Maxwell fluid over a bidirectional stretching surface. Both cases of prescribed surface temperature (PST) and prescribed surface heat flux (PHF) are considered. Computations are made for the velocities and temperatures. Results are plotted and analyzed for PST and PHF cases. Convergence analysis is presented for the velocities and temperatures. Comparison of PST and PHF cases is given and examined.