scholarly journals Numerical solution of Stokes problem for free convection effects in dissipative dusty medium

2004 ◽  
Vol 2004 (72) ◽  
pp. 3975-3988 ◽  
Author(s):  
V. Venkataraman ◽  
K. Kannan
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Skin Friction ◽  
Stokes Problem ◽  
Temperature Fields ◽  
Dust Particles ◽  
Two Phase ◽  
Dusty Fluid ◽  
Dissipative Heat ◽  
Phase Fluid

The flow past an infinite vertical isothermal plate started impulsively in its own plane in a viscous incompressible two-phase fluid has been considered by taking into account the viscous dissipative heat. The coupled nonlinear equations governing the flow are solved for fluid and particle phases by finite difference method. The velocity and temperature fields have been shown graphically forGbeing positive for dusty air and it was observed that the same results hold for water. (Gdenotes the Grashof number andG>0corresponds to cooling of the plate by free convection currents.) The results forG<0(heating of the plate) have been verified and discussed. The numerical values of skin friction and the rate of heat transfer of dusty fluid are shown in tables. The effects ofGandE(the Eckert number) on the flow field are discussed. It is observed that dusty fluid causes an increase in skin friction. The increase in mass concentration of dust particles decreases the heat transfer rate. The presence of inert particles does not admit the reverse type of flow even for large values oft.

scholarly journals Consequence of Heat Transfer on Free Convection Flow of Casson Fluid with Hall Effect

2019 ◽  
Vol 8 (10S) ◽  
pp. 90-95
Keyword(s):  
Heat Transfer ◽  
Differential Equations ◽  
Free Convection ◽  
Hall Effect ◽  
Skin Friction ◽  
Casson Fluid ◽  
Temperature Fields ◽  
Convection Flow ◽  
Free Convection Flow ◽  
Fluid Parameter

Effect of heat transfer on free convection flow of Casson fluid over a vertical plate with Hall effect has been studied. A similarity analysis method was used to transform the system of partial differential equations describing the problem into an ordinary differential equations, Analytical solutions are obtained by solving the ODE to analyze the velocity and temperature fields. Variations of interesting parameters on the velocity, heat transfer and skin friction are observed by plotting graphs. Further, it was concluded that the Casson fluid parameter and hall parameter has an retarding influence on velocity profile and also in the skin friction.

scholarly journals On heat transfer to pulsatile flow of a two-phase fluid

2005 ◽  
Vol 2005 (15) ◽  
pp. 2497-2510
Author(s):  
A. K. Ghosh ◽  
S. P. Chakraborty
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Pulsatile Flow ◽  
Particle System ◽  
Temperature Fields ◽  
Two Phase ◽  
Unsteady Temperature ◽  
Flow Parameters ◽  
Temperature Distributions ◽  
Phase Fluid

The problem of heat transfer to pulsatile flow of a two-phase fluid-particle system contained in a channel bounded by two infinitely long rigid impervious parallel walls has been studied in this paper. The solutions for the steady and the fluctuating temperature distributions are obtained. The rates of heat transfer at the walls are also calculated. The results are discussed numerically with graphical presentations. It is shown that the presence of the particles not only diminishes the steady and unsteady temperature fields but also decreases the reversal of heat flux at the hotter wall irrespective of the influences of other flow parameters.

Free convection effects on the oscillatory flow past an infinite, vertical, porous plate with constant suction. II

1973 ◽  
Vol 333 (1592) ◽  
pp. 37-50 ◽  
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Skin Friction ◽  
Oscillatory Flow ◽  
Porous Plate ◽  
Transient Temperature ◽  
Dissipative Heat ◽  
Constant Suction ◽  
Two Dimensional Flow ◽  
Transient Velocity

An analysis of a two-dimensional flow of an incompressible, viscous fluid is presented here for the unsteady flow. The mathematical analysis having been presented in part I, only the solutions for the transient velocity profiles, transient temperature profiles, the amplitude and the phase of the skin friction and the rate of heat transfer are presented in this paper. They are shown graphically. The effects of heating or cooling the plate ( G < > 0) the Eckert number ( E ), the Prandtl number ( P ), and the frequency ( ω ) are discussed. It has been observed that a reversed type of flow occurs when the plate is heated by the free convection currents. The amplitude of the skin friction is not affected significantly by the free convection currents when the frequency is large. In the case of air, the phase of the skin friction is more, when the plate is cooled than that when it is heated, by the free convection currents. Also, owing to greater viscous dissipative heat for G > 0, or to greater cooling of the plate, the amplitude of the skin friction increases, whereas owing to greater viscous dissipative heat for G < 0 or to greater heating of the plate, the amplitude of the skin friction decreases. But the amplitude of the rate of heat transfer increases owing to greater heating or cooling of the plate. However, it is more when the plate is cooled than that when the plate is heated.

Free-convection effects in the boundary layer along a vertically stretching flat surface

1992 ◽  
Vol 70 (12) ◽  
pp. 1253-1260 ◽  
Author(s):  
John E. Daskalakis
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Free Convection ◽  
Skin Friction ◽  
Flat Surface ◽  
Relaxation Method ◽  
Boussinesq Approximation ◽  
Axial Coordinate ◽  
Prandtl Numbers ◽  
Energy Equations

We assess the effects of free convection on the boundary layer formed along a flat surface stretching vertically in a quiescent fluid. The flow is laminar and incompressible, the buoyancy forces conform to the Boussinesq approximation and the surface temperature is variable. The two-point boundary value problem of the coupled momentum and energy equations is solved using a simple and accurate relaxation method that provides the general nonsimilar solution to the flow. The effect of free-convection currents on velocity and temperature profiles, skin friction, and heat transfer is studied by varying the flow Grashof and Prandtl numbers. Zero shear stress and heat-transfer rate are predicted at some axial coordinate on a surface with decreasing wall temperature. Also the skin friction is markedly modified by the buoyancy while the heat transfer at the surface is correspondingly only moderately influenced.

scholarly journals Laminar free convection induced by a line heat source, and heat transfer from wires at small Grashof numbers

1998 ◽  
Vol 362 ◽  
pp. 199-227 ◽  
Author(s):  
AMABLE LIÑÁN ◽  
VADIM N. KURDYUMOV
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Line Source ◽  
Outer Region ◽  
Analytical Description ◽  
Temperature Fields ◽  
Thermal Plume ◽  
Line Heat Source ◽  
First Approximation ◽  
Wide Range

The buoyancy-induced laminar flow and temperature fields associated with a line source of heat in an unbounded environment are described by numerically solving the non-dimensional Boussinesq equations with the appropriate boundary conditions. The solution is given for values of the Prandtl number, the single parameter, ranging from zero to infinity. The far-field form of the solution is well known, including a self-similar thermal plume above the source. The analytical description close to the source involves constants that must be evaluated with the numerical solution.These constants are used when calculating the free convection heat transfer from wires (or cylinders of non-circular shape) at small Grashof numbers. We find two regions in the flow field: an inner region, scaled with the radius of the wire, where the effects of convection can be neglected in first approximation, and an outer region where, also in first approximation, the flow and temperature fields are those due to a line source of heat. The cases of large and small Prandtl numbers are considered separately. There is good agreement between the Nusselt numbers given by the asymptotic analysis and by the numerical analysis, which we carry out for a wide range of Grashof numbers, extending to very small values the range of existing numerical results; there is also agreement with the existing correlations of the experimental results. A correlation expression is proposed for the relation between the Nusselt and Grashof numbers, based on the asymptotic forms of the relation for small and large Grashof numbers.

The Effect of Mass Transfer on Free Convection

1960 ◽  
Vol 82 (3) ◽  
pp. 260-263 ◽  
Author(s):  
R. Eichhorn
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Free Convection ◽  
Skin Friction ◽  
Leading Edge ◽  
Temperature Profiles ◽  
Constant Wall Temperature ◽  
Constant Property ◽  
Boundary Layer Equations ◽  
Similar Solutions

Consideration is given to the constant property laminar boundary layer equations with free convection and mass transfer. It is shown that similar solutions are possible for blowing rate distributions varying as the distance from the leading edge raised to the power (n − 1)/4 where n is the exponent in a power law surface temperature distribution. Solutions to the equations in the form of skin friction and heat-transfer parameters, and velocity and temperature profiles are presented for the constant wall temperature case for a fluid with Pr = 0.73. The cases considered range from strong suction to strong blowing. Mass transfer has a pronounced effect on the heat transfer but only a slight effect on the skin friction. In light of the solutions presented, these effects are shown to be physically rational.

Momentum and Heat Transfer in Laminar Flow of Gas With Liquid-Droplet Suspension Over a Circular Cylinder

1967 ◽  
Vol 89 (2) ◽  
pp. 185-193 ◽  
Author(s):  
M. E. Goldstein ◽  
Wen-Jei Yang ◽  
J. A. Clark
Keyword(s):  
Heat Transfer ◽  
Circular Cylinder ◽  
Skin Friction ◽  
Gas Flow ◽  
Flow Problem ◽  
Liquid Droplet ◽  
Two Phase ◽  
Momentum And Heat Transfer ◽  
Layer Flow ◽  
Gas Liquid Flow

An analysis has been made to determine the heat transfer and friction characteristics in a two-phase (gas-liquid) flow over a circular cylinder. It is demonstrated that the resulting two-layer flow problem can be formulated exactly within the framework of laminar boundary layer theory. Two cases are studied; (1) For the parameter E greater or equal to 0.1 and the drop trajectories straight and, (2) For E less or equal to 0.1 and for any drop trajectory. Solutions obtained in power series include the local liquid-film thickness, velocity and temperature profiles, skin friction and Nusselt number. Numerical results disclose a significant increase in both heat transfer rate and skin friction over those of a pure gas flow. The theoretical prediction compares favorably with experimental results of Acrivos, et al. [1].

Thermal Convection in an Infinite Porous Medium Induced by a Heated Sphere

1997 ◽  
Vol 119 (3) ◽  
pp. 647-650 ◽  
Author(s):  
R. Ganapathy
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Rayleigh Number ◽  
Free Convection ◽  
Wall Temperature ◽  
Transient Behavior ◽  
Temperature Fields ◽  
Series Expansions ◽  
Medium Permeability ◽  
Velocity And Temperature Fields

This paper investigates the transient behavior of the free convection motion and heat transfer induced by a heated sphere with prescribed wall temperature embedded instantaneously in an infinite porous medium. Solutions for the velocity and temperature fields have been obtained in the form of series expansions in Rayleigh number which is based on the medium permeability and the temperature of the sphere. All discussions are based on the assumption that the flow is governed by Darcy's law and the thermal Rayleigh number is small.

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