Mixed convection heat transfer over a non-linear stretching surface with variable fluid properties

This article presents a numerical solution for the steady two-dimensional mixed convection MHD flow of an electrically conducting viscous fluid over a vertical stretching sheet, in its own plane. The stretching velocity and the transverse magnetic field are assumed to vary as a power function of the distance from the origin. The temperature dependent fluid properties, namely, the fluid viscosity and the thermal conductivity are assumed to vary, respectively, as an inverse function of the temperature and a linear function of the temperature. A generalized similarity transformation is introduced to study the influence of temperature dependent fluid properties. The transformed boundary layer equations are solved numerically, using a finite difference scheme known as Keller Box method, for several sets of values of the physical parameters, namely, the stretching parameter, the temperature dependent viscosity parameter, the magnetic parameter, the mixed convection parameter, the temperature dependent thermal conductivity parameter and the Prandtl number. The numerical results thus obtained for the flow and heat transfer characteristics reveal many interesting behaviors. These behaviors warrant further study of the effects of the physical parameters on the flow and heat transfer characteristics. Here it may be noted that, in the case of the classical Navier-Stokes fluid flowing past a horizontal stretching sheet, McLeod and Rajagopal (1987) 42 showed that there exist an unique solution to the problem. This may not be true in the present case. Hence we would like to explore the non-uniqueness of the solution and present the findings in the subsequent paper. © 2009 Elsevier Ltd. All rights reserved

MHD power-law fluid flow and heat transfer over a non-isothermal stretching sheet

This article presents a numerical solution for the magnetohydrodynamic (MHD) non-Newtonian power-law fluid flow over a semi-infinite non-isothermal stretching sheet with internal heat generation/absorption. The flow is caused by linear stretching of a sheet from an impermeable wall. Thermal conductivity is assumed to vary linearly with temperature. The governing partial differential equations of momentum and energy are converted into ordinary differential equations by using a classical similarity transformation along with appropriate boundary conditions. The intricate coupled non-linear boundary value problem has been solved by Keller box method. It is important to note that the momentum and thermal boundary layer thickness decrease with increase in the power-law index in presence/absence of variable thermal conductivity

Unsteady convective boundary layer flow of a viscous fluid at a vertical surface with variable fluid properties

In this paper we present numerical solutions to the unsteady convective boundary layer flow of a viscous fluid at a vertical stretching surface with variable transport properties and thermal radiation. Both assisting and opposing buoyant flow situations are considered. Using a similarity transformation, the governing time-dependent partial differential equations are first transformed into coupled, non-linear ordinary differential equations with variable coefficients. Numerical solutions to these equations subject to appropriate boundary conditions are obtained by a second order finite difference scheme known as the Keller-Box method. The numerical results thus obtained are analyzed for the effects of the pertinent parameters namely, the unsteady parameter, the free convection parameter, the suction/injection parameter, the Prandtl number, the thermal conductivity parameter and the thermal radiation parameter on the flow and heat transfer characteristics. It is worth mentioning that the momentum and thermal boundary layer thicknesses decrease with an increase in the unsteady parameter. © 2012 Published by Elsevier Ltd

Axisymmetric magneto-hydrodynamic (MHD) flow and heat transfer at a non-isothermal stretching cylinder

An investigation is made to study the effects of transverse curvature and the temperature dependent thermal conductivity on the magneto-hydrodynamic (MHD) axisymmetric flow and heat transfer characteristics of a viscous incompressible fluid induced by a non-isothermal stretching cylinder in the presence of internal heat generation/absorption. It is assumed that the cylinder is stretched in the axial direction with a linear velocity and the surface temperature of the cylinder is subjected to vary non-isothermally. Here the thermal conductivity is assumed to vary linearly with temperature. Using a similarity transformation, the governing system of partial differential equations is first transformed into coupled non-linear ordinary differential equations with variable coefficients. The resulting intricate non-linear boundary value problem is solved numerically by a second order finite difference scheme for different values of the pertinent parameters for two cases: (i) the prescribed surface temperature (PST case) and (ii) the prescribed heat flux (PHF case). Numerical results are obtained for two different cases namely, zero and non-zero values of the curvature parameter to get the effects on the velocity and temperature fields. The combined effects of the curvature parameter and the thermal conductivity parameter are examined. The physical significances of the numerical results are presented for several limiting cases. © 2012 Elsevier Inc. All rights reserved

Diffusion of a chemically reactive species of a power-law fluid past a stretching surface

A numerical solution for the steady magnetohydrodynamic (MHD) non-Newtonian power-law fluid flow over a continuously moving surface with species concentration and chemical reaction has been obtained. The viscous flow is driven solely by the linearly stretching sheet, and the reactive species emitted from this sheet undergoes an isothermal and homogeneous one-stage reaction as it diffuses into the surrounding fluid. Using a similarity transformation, the governing non-linear partial differential equations are transformed into coupled nonlinear ordinary differential equations. The governing equations of the mathematical model show that the flow and mass transfer characteristics depend on six parameters, namely, the power-law index, the magnetic parameter, the local Grashof number with respect to species diffusion, the modified Schmidt number, the reaction rate parameter, and the wall concentration parameter. Numerical solutions for these coupled equations are obtained by the KellerBox method, and the solutions obtained are presented through graphs and tables. The numerical results obtained reveal that the magnetic field significantly increases the magnitude of the skin friction, but slightly reduces the mass transfer rate. However, the surface mass transfer strongly depends on the modified Schmidt number and the reaction rate parameter; it increases with increasing values of these parameters. The results obtained reveal many interesting behaviors that warrant further study of the equations related to non-Newtonian fluid phenomena, especially shear-thinning phenomena. Shear thinning reduces the wall shear stress. © 2011 Elsevier Ltd. All rights reserved

Convergence of Ishikawa Iteration Process for General Class of Function

In this paper, we introduce a general class of function and prove the convergence result of Ishikawa iteration considered in Banach spaces

The effect of variable viscosity on MHD viscoelastic fluid flow and heat transfer over a stretching sheet

An analysis has been carried out to study the momentum and heat transfer characteristics in an incompressible electrically conducting non-Newtonian boundary layer flow of a viscoelastic fluid over a stretching sheet. The partial differential equations governing the flow and heat transfer characteristics are converted into highly non-linear coupled ordinary differential equations by similarity transformations. The effect of variable fluid viscosity, Magnetic parameter, Prandtl number, variable thermal conductivity, heat source/sink parameter and thermal radiation parameter are analyzed for velocity, temperature fields, and wall temperature gradient. The resultant coupled highly non-linear ordinary differential equations are solved numerically by employing a shooting technique with fourth order Runge-Kutta integration scheme. The fluid viscosity and thermal conductivity, respectively, assumed to vary as an inverse and linear function of temperature. The analysis reveals that the wall temperature profile decreases significantly due to increase in magnetic field parameter. Further, it is noticed that the skin friction of the sheet decreases due to increase in the Magnetic parameter of the flow characteristics. © 2009 Elsevier B.V. All rights reserved

Peristaltic-Ciliary Flow of A Casson Fluid through An Inclined Tube

The paper is concerned with the peristaltic-ciliary transport of a viscoplastic fluid (Casson fluid) through an inclined cylindrical tube. The peristalsis-cilia induced motion is analysed in the moving frame of reference under the lubrication approximations. Solutions to the flow characteristics petering to yielded and unyielded regions are obtained. The effects of various physical parameters on the axial velocity, the pumping characteristics, the pressure rise, and the frictional force over one wavelength, along with the trapping phenomenon are presented through graphs. Further, the peristaltic flow and peristaltic-ciliary flow results are compared. It is noticed that the axial velocity and the size of trapping bolus in the unplug flow region decrease with an increase in the yield stress. In addition, the axial velocity and the axial pressure gradient in the peristaltic-ciliary pumping are higher than those in the peristaltic pumping

Occurrence of Banana bract mosaic virus on Musa ornata Roxb based hybrids in India

Not AvailableMusa ornata, wild species of banana is being used as a cut flower, potted plants and for landscape gardening etc., They are also being utilized in banana hybridization programmes for introgressing pest and disease tolerant traits into banana cultivars in addition to the development of inter specific ornamental banana hybrids. Symptoms of banana bract mosaic virus (BBrMV) was observed in the bracts of interspecific M. ornata based hybrid developed using another wild species i.e., Musa rubra Kurz at ICAR-National Research Centre for Banana (NRCB), Tiruchirapalli. Presence of the virus in the bracts, leaves and roots of symptomatic plants was confirmed through triple antibody sandwich enzyme linked immunosorbent assay with BBrMV monoclonal and polyclonal antibodies. BBrMV HC-Pro (1370 bp), CP (900 bp) and VPg (570 bp) genes were amplified from the infected bracts using reverse transcriptase polymerase chain reaction with BBrMV respective gene primers. The amplicons of these three genes were cloned and sequenced. Blastn analysis revealed that HC-Pro, VPg and CP gene sequences has 97.67%, 97.72% and 99.67% similarity with the respective gene sequences of BBrMV infecting banana. Phylogenetic analysis clustered the test isolate with other BBrMV isolates of banana and other hosts based on CP and HC-Pro and VPg gene sequences. The virus is transmitted through Pentalonia nigronervosa and the transmitted plants expressed symptoms under glass house conditions. To the best of our knowledge, this is the first report of BBrMV on ornamental M. ornata hybrid in India and its transmission occurs through Pentalonia nigronervosa.ICAR-Consortia Research Platform (CRP) on vaccines and diagnostic