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Mahantesh M. Nandeppanavar - One of the best experts on this subject based on the ideXlab platform.

  • heat transfer in mhd viscoelastic Boundary Layer flow over a stretching sheet with non uniform heat source sink
    Communications in Nonlinear Science and Numerical Simulation, 2009
    Co-Authors: Subhas M Abel, Mahantesh M. Nandeppanavar
    Abstract:

    Abstract This paper presents the study of momentum and heat transfer characteristics in a hydromagnetic flow of viscoelastic liquid over a stretching sheet with non-uniform heat source, where the flow is generated due to a linear stretching of the sheet and influenced by uniform magnetic field applied vertically. Here an analysis has been carried out to study the effect of magnetic field on the visco-elastic liquid flow and heat transfer over a stretching sheet with non-uniform heat source. The non-linear Boundary Layer Equation for momentum is converted into ordinary differential Equation by means of similarity transformation and is solved exactly. Heat transfer differential Equation is also solved analytically. The effect of magnetic field on velocity, skin friction and temperature profiles are presented graphically and discussed.

  • Viscoelastic MHD flow and heat transfer over a stretching sheet with viscous and ohmic dissipations
    Communications in Nonlinear Science and Numerical Simulation, 2008
    Co-Authors: M. Subhas Abel, Emmanuel Sanjayanand, Mahantesh M. Nandeppanavar
    Abstract:

    Abstract A mathematical analysis has been carried out on momentum and heat transfer characteristics in an incompressible electrically conducting viscoelastic Boundary Layer fluid flow over a linear stretching sheet. Momentum Boundary Layer Equation takes into account the effect of transverse magnetic field and electric field. Thermal Boundary Layer Equation takes into account the viscous dissipation and Ohmic dissipation due to transverse magnetic field and electric field. Highly non-linear momentum Boundary Layer Equation and thermal Boundary Layer Equation are converted into similarity Equations and then solved numerically by employing fifth order Runge–Kutta–Fehlberg method with shooting. The results are analysed for the situation when stretching Boundary is prescribed by non-isothermal temperature, namely, prescribed surface temperature (PST) which varies quadratically with the flow directional coordinate x. The effects of various physical parameters like viscoelastic parameter, Prandtl number, local Reynolds number, Eckert number Hartmann number and electric parameter on various momentum and heat transfers characteristics are analysed. Some of the important findings of this paper are (i) The combined effect of increasing the values of local Reynolds number Re x and local electric parameter (E1) is to decrease skin-friction coefficient Cf largely. (ii) In presence of magnetic field the effect of electric field is to decrease temperature near the stretching Boundary and increase the same significantly away from the stretching sheet. (iii) If electric field is present and the Prandtl number is lower then there would be a significant decrease of temperature near the Boundary sheet in case of viscoelastic fluid. (iv) The presence of electric field reverses the direction of heat transfer on the Boundary stretching sheet more significantly in case of viscoelastic fluid.

Dulal Pal - One of the best experts on this subject based on the ideXlab platform.

  • heat and mass transfer in mhd non darcian flow of a micropolar fluid over a stretching sheet embedded in a porous media with non uniform heat source and thermal radiation
    Communications in Nonlinear Science and Numerical Simulation, 2010
    Co-Authors: Dulal Pal, Sewli Chatterjee
    Abstract:

    Abstract A mathematical analysis has been carried out to study magnetohydrodynamic Boundary Layer flow, heat and mass transfer characteristic on steady two-dimensional flow of a micropolar fluid over a stretching sheet embedded in a non-Darcian porous medium with uniform magnetic field. Momentum Boundary Layer Equation takes into account of transverse magnetic field whereas energy Equation takes into account of Ohmic dissipation due to transverse magnetic field, thermal radiation and non-uniform source effects. An analysis has been performed for heating process namely the prescribed wall heat flux (PHF case). The governing system of partial differential Equations is first transformed into a system of non-linear ordinary differential Equations using similarity transformation. The transformed Equations are non-linear coupled differential Equations which are then linearized by quasi-linearization method and solved very efficiently by finite-difference method. Favorable comparisons with previously published work on various special cases of the problem are obtained. The effects of various physical parameters on velocity, temperature, concentration distributions are presented graphically and in tabular form.

  • effect of variable viscosity on mhd non darcy mixed convective heat transfer over a stretching sheet embedded in a porous medium with non uniform heat source sink
    Communications in Nonlinear Science and Numerical Simulation, 2010
    Co-Authors: Dulal Pal, Hiranmoy Mondal
    Abstract:

    Abstract An analysis has been presented to investigate the effect of temperature-dependent viscosity on non-Darcy MHD mixed convective heat transfer past a porous medium by taking into account of Ohmic dissipation and non-uniform heat source/sink. Thermal Boundary Layer Equation takes into account of viscous dissipation and Ohmic dissipation due to transverse magnetic field and electric field. The governing fundamental Equations are first transformed into system of ordinary differential Equations using self-similarity transformation and are solved numerically by using the fifth-order Runge–Kutta–Fehlberg method with shooting technique for various values of the physical parameters. The effects of variable viscosity, porosity, Eckert number, Prandtl number, magnetic field, electric field and non-uniform heat source/sink parameters on velocity and temperature profiles are analyzed and discussed. Favorable comparisons with previously published work on various special cases of the problem are obtained. Numerical results on the development of the local skin-friction co-efficient and local Nusselt number with non-uniform heat source/sink are tabulated for various physical parameters to show the interesting aspects of the solution.

Hannes Uecker - One of the best experts on this subject based on the ideXlab platform.

  • an integral Boundary Layer Equation for film flow over inclined wavy bottoms
    Physics of Fluids, 2009
    Co-Authors: Tobias Hacker, Hannes Uecker
    Abstract:

    We study the flow of an incompressible liquid film down a wavy incline. Applying a Galerkin method with only one ansatz function to the Navier–Stokes Equations, we derive a second-order weighted residual integral Boundary Layer Equation, which, in particular, may be used to describe eddies in the troughs of the wavy bottom. We present numerical results which show that our model is qualitatively and quantitatively accurate in wide ranges of parameters, and we use the model to study some new phenomena, for instance, the occurrence of a short wave instability (at least in a phenomenological sense) for laminar flows which does not exist over a flat bottom.

  • an integral Boundary Layer Equation for film flow over inclined wavy bottoms
    arXiv: Analysis of PDEs, 2008
    Co-Authors: Tobias Hacker, Hannes Uecker
    Abstract:

    We study the flow of an incompressible liquid film down a wavy incline. Applying a Galerkin method with only one ansatz function to the Navier-Stokes Equations we derive a second order weighted residual integral Boundary Layer Equation, which in particular may be used to describe eddies in the troughs of the wavy bottom. We present numerical results which show that our model is qualitatively and quantitatively accurate in wide ranges of parameters, and we use the model to study some new phenomena, for instance the occurrence of a short wave instability for laminar flows which does not exist over flat bottom.

  • approximation of the integral Boundary Layer Equation by the kuramoto sivashinsky Equation
    Siam Journal on Applied Mathematics, 2003
    Co-Authors: Hannes Uecker
    Abstract:

    In suitable parameter regimes the integral Boundary Layer Equation (IBLe) can be formally derived as a long wave approximation for the flow of a viscous incompressible fluid down an inclined plane. For very long waves with small amplitude, the IBLe can be further reduced to the Kuramoto--Sivashinsky Equation (KSe). Here we justify this reduction of the IBLe to the KSe. Using energy estimates, we show that solutions of the KSe approximate solutions of the IBLe over sufficiently long time scales. This is a step towards understanding the approximation properties of the KSe for the full Navier--Stokes system describing the inclined film flow.

Sewli Chatterjee - One of the best experts on this subject based on the ideXlab platform.

  • heat and mass transfer in mhd non darcian flow of a micropolar fluid over a stretching sheet embedded in a porous media with non uniform heat source and thermal radiation
    Communications in Nonlinear Science and Numerical Simulation, 2010
    Co-Authors: Dulal Pal, Sewli Chatterjee
    Abstract:

    Abstract A mathematical analysis has been carried out to study magnetohydrodynamic Boundary Layer flow, heat and mass transfer characteristic on steady two-dimensional flow of a micropolar fluid over a stretching sheet embedded in a non-Darcian porous medium with uniform magnetic field. Momentum Boundary Layer Equation takes into account of transverse magnetic field whereas energy Equation takes into account of Ohmic dissipation due to transverse magnetic field, thermal radiation and non-uniform source effects. An analysis has been performed for heating process namely the prescribed wall heat flux (PHF case). The governing system of partial differential Equations is first transformed into a system of non-linear ordinary differential Equations using similarity transformation. The transformed Equations are non-linear coupled differential Equations which are then linearized by quasi-linearization method and solved very efficiently by finite-difference method. Favorable comparisons with previously published work on various special cases of the problem are obtained. The effects of various physical parameters on velocity, temperature, concentration distributions are presented graphically and in tabular form.

Andrei D. Polyanin - One of the best experts on this subject based on the ideXlab platform.

  • one dimensional reductions and functional separable solutions to unsteady plane and axisymmetric Boundary Layer Equations for non newtonian fluids
    International Journal of Non-linear Mechanics, 2016
    Co-Authors: Andrei D. Polyanin, Alexei I Zhurov
    Abstract:

    Abstract The paper deals with Equations describing the unsteady axisymmetric Boundary Layer of power-law non-Newtonian fluids on a body of revolution. The axisymmetric Boundary-Layer Equation for the stream function is shown to reduce to a single third-order PDE of the form w tz + w z w xz − w x w zz = κ r n + 1 ( x ) w zz n − 1 w zzz + F ( t , x ) , where n is a rheological parameter of the fluid; the function r(x), determining the shape of the body, is assumed arbitrary. For this non-linear PDE, we describe one-dimensional reductions as well as a number of new generalized and functional separable solutions, which depend on two to five arbitrary functions. The solutions are obtained with the direct method of functional separation of variables by using particular solutions to an auxiliary ODE and systems of first-order PDEs. Many of the solutions are expressed in terms of elementary functions, which, together with significant arbitrariness, makes them especially useful for solving certain model problems and testing numerical and approximate analytical methods in fluid dynamics. Apart from power-law fluids, the paper looks at three-parameter polynomial and generalized Sisko models of non-Newtonian fluids. The unsteady plane Boundary-Layer Equations for the general non-Newtonian fluid model are shown to admit a reduction to an ODE. The paper presents new exact solutions to the plane Boundary-Layer Equations for power-law fluids as well as some other rheologically complex fluids.