/pdf/laminar-free-convection-heat-transfer-from-vertical-47mkrktfsy.pdf

Laminar free convection heat transfer from vertical cylinders

3 Abstract: In this present work the effects of time-dependent axial velocity Effects on MHD free convection flow of viscous fluid over a vertical moving cylinder with thermal conductivity and viscosity depending on temperature,the surface of which is exposed to a constant wall temperatures. Numerical solutions of the Navier- Stokes equations, concentration equation and energy equation are derived in this problem. A reduction of these equations is obtained by use of appropriate transformations. The semi-similar solution of the Navier-Stokes equations, concentration equation and energy equation has been obtained numerically using by the implicit finite difference scheme of Crank-Nicolson's type. The velocity, concentration and temperature profiles for different values of cylinder axial velocity are plotted.The influence of the thermal Grashof number, mass Grashof number, Schmidt number, Prandtl number, viscosity-variation parameter, thermal conductivity variation parameter and magnetic parameter for different values of cylinder axial velocity on free convection flow and heat transfer are discussed. It is observed that, when Prandtl number increases the velocity and temperature decrease in the boundary layer. Also, it is found that as increase in the magnetic parameter leads to decrease in the velocity feld and rise in the thermal boundary thickness.

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Time-Dependent Axial Velocity Effects on Mhd Free Convection Flow and Heat Transfer of a Viscous Fluid over a Vertical Moving Cylinder with Thermal Conductivity and Viscosity Depending on Temperature

This paper presents a numerical analysis of the MHD free convection and mass transfer flow of a dissipative fluid along a vertical plate with time-dependent plate velocity, the surface of which is exposed to a constant heat flux. The non-linear system of partia l differential equations is numerically solved by the implicit finite differenc e scheme of Crank- Nicolson's type. The velocity, temperature and conc entration profiles for different values of plate velocity are plotted. The influence of the buoyancy ratio parameter, dissipation number, Grashof number , Prandtl number, Schmidt number and magnetic parameter on heat and m ass transfer are discussed. It is found that, the velocity as well as temperature increases with effects dissipation number. the velocity and temper ature decreases with increases in the magnetic parameter, while concentr ation profiles increases with increases in magnetic parameter. the velocity increases as well as the temperature and the concentration decreases with i ncreases buoyancy ratio parameter. The velocity increases as well as the te mperature and the concentration decreases with increases Grashof numb er.

Komeil Rahmdel

Papers

Time-Dependent Axial Velocity Effects on Mhd Free Convection Flow and Heat Transfer of a Viscous Fluid over a Vertical Moving Cylinder with Thermal Conductivity and Viscosity Depending on Temperature

Time-Dependent Plate Velocity Effects on MHD Free Convection and Mass Transfer Flow of a Dissipative Fluid over a Vertical Plate