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Faiza A Salama - One of the best experts on this subject based on the ideXlab platform.

  • the effects of temperature dependent viscosity and thermal conductivity on unsteady mhd convective heat transfer past a semi infinite vertical porous Moving Plate with variable suction
    Computational Materials Science, 2007
    Co-Authors: M.a. Seddeek, Faiza A Salama
    Abstract:

    In this article, we studied the effects of variable viscosity and thermal conductivity on an unsteady two-dimensional laminar flow of a viscous incompressible conducting fluid past a semi-infinite vertical porous Moving Plate taking into account the effect of a magnetic field in the presence of variable suction. The fluid viscosity is assumed to vary as an inverse linear function of temperature but the thermal conductivity is assumed to vary as a linear function of temperature. It is assumed that the porous Plate moves with a constant velocity in the direction of fluid flow, and the free stream velocity follows the exponentially increasing small perturbation law. The governing equations for the flow are transformed into a system of nonlinear ordinary differential equations by perturbation technique and are solved numerically by using the shooting method. The effects of the various parameters on the velocity and temperature profiles as well as the surface skin-friction coefficient are presented graphically.

M.a. Seddeek - One of the best experts on this subject based on the ideXlab platform.

Ali J Chamkha - One of the best experts on this subject based on the ideXlab platform.

  • soret effect due to mixed convection on unsteady magnetohydrodynamic flow past a semi infinite vertical permeable Moving Plate in presence of thermal radiation heat absorption and homogenous chemical reaction
    International Journal of Applied and Computational Mathematics, 2017
    Co-Authors: M C Raju, Ali J Chamkha, J Philip, S V K Varma
    Abstract:

    In this article we have investigated the Soret effect due to mixed convection on unsteady magneto hydrodynamic flow past a semi-infinite vertical permeable Moving Plate in presence of thermal radiation, heat absorption and homogenous chemical reaction, subjected to variable suction. The Plate is assumed to be embedded in a uniform porous medium and moves with a constant velocity in the flow direction in the presence of a transverse magnetic field. The equations governing the flow are transformed into a system of nonlinear ordinary differential equations by using perturbation technique. Graphical results for the velocity distribution, temperature distribution and concentration distribution based on the numerical solutions are presented and discussed. We also discuss the effects of various parameters on the skin-friction coefficient and the rate of heat transfer in the form of Nusselt number and rate of mass transfer in the form of Sherwood number at the surface. Velocity distribution is observed to increase with an increase in Soret number and in the presence of permeability, where as it shows reverse effects in the case of heat absorption coefficient, magnetic parameter, radiation parameter and chemical reaction parameter.

  • unsteady mhd convective heat and mass transfer past a semi infinite vertical permeable Moving Plate with heat absorption
    International Journal of Engineering Science, 2004
    Co-Authors: Ali J Chamkha
    Abstract:

    The problem of unsteady, two-dimensional, laminar, boundary-layer flow of a viscous, incompressible, electrically conducting and heat-absorbing fluid along a semi-infinite vertical permeable Moving Plate in the presence of a uniform transverse magnetic field and thermal and concentration buoyancy effects is considered. The Plate is assumed to move with a constant velocity in the direction of fluid flow while the free stream velocity is assumed to follow the exponentially increasing small perturbation law. Time-dependent wall suction is assumed to occur at the permeable surface. The dimensionless governing equations for this investigation are solved analytically using two-term harmonic and non-harmonic functions. The obtained analytical results reduce to previously published results on a special case of the problem. Numerical evaluation of the analytical results is performed and some graphical results for the velocity, temperature and concentration profiles within the boundary layer and tabulated results for the skin-friction coefficient, Nusselt number and the Sherwood number are presented and discussed.

Youn J Kim - One of the best experts on this subject based on the ideXlab platform.

  • unsteady mhd convective heat transfer past a semi infinite vertical porous Moving Plate with variable suction
    International Journal of Engineering Science, 2000
    Co-Authors: Youn J Kim
    Abstract:

    Abstract In this paper we study the unsteady two-dimensional laminar flow of a viscous incompressible electrically conducting fluid in the vicinity of a semi-infinite vertical porous Moving Plate in the presence of a transverse magnetic field. The Plate moves with constant velocity in the direction of fluid flow, and the free stream velocity follows the exponentially increasing small perturbation law. A uniform magnetic field acts perpendicular to the porous surface which absorbs the fluid with a suction velocity varying with time. The effects of material parameters on the velocity and temperature fields across the boundary layer are investigated. Numerical results show that for a constant Plate Moving velocity with a given magnetic and permeability parameters, and Prandtl and Grashof numbers, the effect of increasing values of suction velocity parameter results in a slight increasing surface skin friction for lower values of Plate Moving velocity. It is also observed that for several values of Prandtl number, the surface heat transfer decreases by increasing the magnitude of suction velocity.

V. Naso - One of the best experts on this subject based on the ideXlab platform.

  • Radiative Effects on Mixed Convection in a Uniformly Heated Vertical Convergent Channel with an Unheated Moving Plate
    Advances in Applied Mathematics and Mechanics, 2011
    Co-Authors: A. Andreozzi, N. Bianco, V. Naso
    Abstract:

    Fluids engineering is extremely important in a wide variety of materials processing systems, such as soldering, welding, extrusion of plastics and other polymeric materials, Chemical Vapor Deposition (CVD), composite materials manufacturing. In particular, mixed convection due to Moving surfaces is very important in these applications. Mixed convection in a channel, as a result of buoyancy and motion of one of its walls has received little research attention and few guidelines are available for choosing the best performing channel configuration, particularly when radiative effects are significant. In this study a numerical investigation of the effect of radiation on mixed convection in air due to the interaction between a buoyancy flow and an unheated Moving Plate induced flow in a uniformly heated convergent vertical channel is carried out. The Moving Plate has a constant velocity and moves in the buoyancy force direction. The principal walls of the channel are heated at uniform heat flux. The numerical analysis is accomplished by means of the commercial code Fluent. The effects of the wall emissivity, the minimum channel spacing, the converging angle and the Moving Plate velocity are investigated and results in terms of air velocity and temperature fields inside the channel and wall temperature profiles, both of the Moving and the heated Plates, are given. Nusselt numbers, both accounting and not for the radiative contribution to heat removal, are also presented.

  • Effect of a Moving Plate on heat transfer in a uniform heat flux vertical channel
    International Journal of Heat and Mass Transfer, 2008
    Co-Authors: A. Andreozzi, N. Bianco, O. Manca, V. Naso
    Abstract:

    Abstract A numerical investigation of mixed convection in air due to the interaction between a buoyancy flow and the flow induced by a Moving Plate in a vertical channel is carried out. An adiabatic Plate moves at a constant velocity in the mid-plane of the channel in the direction of the buoyancy force and the principal walls of the channel are heated at uniform heat flux. The effects of the channel aspect ratio, Rayleigh and Reynolds numbers are investigated and results in terms of the dimensionless channel wall and Moving Plate temperatures are given. Results show that the larger the channel aspect ratio, L / ( b / 2 ) , the stronger the effects of the Moving Plate. Increasing Reynolds number significantly decreases the dimensionless temperature of the channel walls. A composite correlation between Nusselt number and Reynolds and Richardson numbers is proposed in the range from natural convection to forced convection up to Re = 1.32 × 10 4 and 9.86 × 10 - 6 ⩽ Ri ⩽ 1.15 × 10 3 , for the channel aspect ratio in the [20.3–81.2] range.

  • Numerical Analysis Of Mixed Convection In Air InAn Inclined Channel With A Moving Plate
    Computational Methods and Experimental Measurements XIII, 2007
    Co-Authors: A. Andreozzi, N. Bianco, G. Lacasa, V. Naso
    Abstract:

    A numerical investigation of mixed convection in air due to the interaction between a buoyancy flow and a Moving Plate induced flow in an inclined channel is presented. The Moving Plate has a constant velocity and is unheated whereas the other channel wall is stationary and heated at uniform heat flux. The numerical analysis is obtained by means of the commercial Fluent code. The effects of the inclination angle, channel spacing, heat flux and Moving Plate velocity are investigated and results in terms of the heated channel wall and Moving Plate temperatures are given.

  • Mixed Convection Heat Transfer in a Convergent Vertical Channel With a Moving Plate
    Volume 4: Fatigue and Fracture Heat Transfer Internal Combustion Engines Manufacturing and Technology and Society, 2006
    Co-Authors: A. Andreozzi, N. Bianco, G. Lacasa, V. Naso
    Abstract:

    A numerical investigation of mixed convection in air in a convergent vertical channel, due to the interaction between a buoyancy flow and a Moving Plate induced flow, is presented. The Plate moves at a constant velocity along the buoyancy force direction and the principal inclined walls of the channel are heated at uniform heat flux. The numerical analysis is carried out by means of the finite volume method, using the commercial code Fluent. The effects of the channel spacing, wall heat flux, Moving Plate velocity and converging angle are investigated. Heated wall temperature increases at increasing converging angle, except for natural convection in a 10 mm minimum channel gap. The effect of the converging angle on the wall temperatures is less marked at the larger channel spacing. Maximum temperature of the Moving Plate is attained in the parallel wall channel for a 30 W m−2 wall heat flux, both in the 10 mm and 40 mm channel, whereas for a 220 W m−2 wall heat flux in the 40 mm channel in mixed convection, maximum wall temperatures are exhibited for a 10° angle. Nusselt, Reynolds and Richardson numbers are correlated by a monomial equation for each converging angle and a unique monomial correlation for all investigated angles in the 2.1·10−2 – 5.1·105 Richardson number range is presented.Copyright © 2006 by ASME

  • Mixed Convection Heat Transfer In AVertical Channel With A Moving Plate
    2005
    Co-Authors: A. Andreozzi, N. Bianco, O. Manca, V. Naso
    Abstract:

    In this study a numerical investigation of mixed convection in air due to the interaction between a buoyancy flow and a Moving Plate induced flow in a vertical channel is carried out. The Moving Plate has a constant velocity and moves along the buoyancy force direction whereas the principal walls of the channel are heated with uniform heat flux. The effects of the channel spacing, heat flux and Moving Plate velocity are investigated and results in terms of the channel wall and Moving Plate temperatures are given. Results show that the Moving Plate effects are more significant when the channel gap b is lower, for lower Moving Plate velocity values. For higher Moving Plate velocity values these effects are more considerable for all b values and for lower heat flux values.