Unsteady Free-Convection Flow on a Vertical Oscillating Porous Plate With Constant Heating

2008 ◽  
Vol 76 (1) ◽  
Author(s):  
C. J. Toki
Keyword(s):  
Free Convection ◽  
Porous Plate ◽  
Convection Flow ◽  
Heating Effects ◽  
Laplace Transform Technique ◽  
The Laplace Transform ◽  
Suction Or Injection ◽  
Constant Heating ◽  
Oscillating Plate ◽  
Special Case

In this paper, we consider the unsteady free-convection flows of a viscous and incompressible fluid near an oscillating porous infinite vertical plate (or wall) during the heating of the plate. The governing equations are solved in closed form by the Laplace transform technique, when the Prandtl number (Pr) of the fluid is arbitrary and the suction (or injection) is constant. This solution is applied for a special case of the constant heating effects from the harmonically oscillating plate. The resulting velocity and temperature are shown graphically and are also discussed for the case of air (Pr=0.71) or water (Pr=7.0) flows.

Free Convection and Mass Transfer Flow Near a Moving Vertical Porous Plate: An Analytical Solution

2008 ◽  
Vol 75 (1) ◽  
Author(s):  
C. J. Toki
Keyword(s):  
Mass Transfer ◽  
Analytical Solution ◽  
Free Convection ◽  
Schmidt Number ◽  
Porous Plate ◽  
Grashof Number ◽  
Vertical Porous Plate ◽  
Laplace Transform Technique ◽  
The Laplace Transform ◽  
Transfer Flow

An exact solution of the problem of the unsteady free convection and mass transfer flow near an infinite vertical porous plate, which moves with time-dependent velocity in a viscous and incompressible fluid, is presented here by the Laplace transform technique. All expressions of the new solutions of the present problem were obtained in closed forms with arbitrary Prandtl number (Pr), Schmidt number (Sc), thermal Grashof number (Gr), and mass Grashof number (Gm). Two applications of physical interest for porous or nonporous plate are discussed. Applying numerical values into the expressions of analytical solution, we was also discussed the vertical air flows—the usual phenomenon at plumes into the atmosphere.

scholarly journals Influence of Thermal Radiation on Unsteady MHD Free Convection Flow of Jeffrey Fluid over a Vertical Plate with Ramped Wall Temperature

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Nor Athirah Mohd Zin ◽  
Ilyas Khan ◽  
Sharidan Shafie
Keyword(s):  
Free Convection ◽  
Thermal Radiation ◽  
Wall Temperature ◽  
Vertical Plate ◽  
Convection Flow ◽  
Jeffrey Fluid ◽  
Dimensionless Time ◽  
Free Convection Flow ◽  
Laplace Transform Technique ◽  
The Laplace Transform

Influence of thermal radiation on unsteady magnetohydrodynamic (MHD) free convection flow of Jeffrey fluid over a vertical plate with ramped wall temperature is studied. The Laplace transform technique is used to obtain the analytical solutions. Expressions for skin friction and Nusselt number are also obtained. Results of velocity and temperature distributions are shown graphically for embedded parameters such as Jeffrey fluid parameterλ, Prandtl numberPr, Grashof numberGr, Hartmann numberHa, radiation parameterRd, and dimensionless timeτ. It is observed that the amplitude of velocity and temperature profile for isothermal are always higher than ramped wall temperature.

A Note on Exact Solutions for the Unsteady Free Convection Flow of a Jeffrey Fluid

2015 ◽  
Vol 70 (6) ◽  
pp. 397-401 ◽  
Author(s):  
Ilyas Khan
Keyword(s):  
Shear Stress ◽  
Free Convection ◽  
Exact Solutions ◽  
Newtonian Fluid ◽  
Numerical Solutions ◽  
Convection Flow ◽  
Jeffrey Fluid ◽  
Free Convection Flow ◽  
Laplace Transform Technique ◽  
The Laplace Transform

AbstractIn this note, we investigate the unsteady free convection flow of a Jeffrey fluid past an infinite isothermal vertical plate. Exact solutions are obtained using the Laplace transform technique. These solutions are expressed in terms of exponential and complementary error functions, and satisfy all imposed initial and boundary conditions as well as the governing equations. The expression for the shear stress is also evaluated. The corresponding solutions for a Newtonian fluid can be easily obtained as a special case. It is found from the velocity and shear stress solutions that they strongly depend on the material parameters of a Jeffrey fluid. The exact solutions obtained here can be used as a benchmark for checking the correctness of other approximate or numerical solutions. In addition, this note will help in understanding the characteristics of non-Newtonian fluid flows that are subject to free convection due to buoyancy force.

Heat Transfer in Eccentric-Concentric Rotation of a Disk and Fluid at Infinity

2016 ◽  
Vol 13 (10) ◽  
pp. 6482-6487
Author(s):  
Ilyas Khan ◽  
Tarek Nabil Ahmed Abdelhameed ◽  
L. C. C Dennis
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Strong Influence ◽  
Fluid Velocity ◽  
Convection Flow ◽  
Dimensionless Time ◽  
Free Convection Flow ◽  
Laplace Transform Technique ◽  
The Laplace Transform ◽  
Convection Parameter

Heat transfer due to free convection flow in eccentric-concentric rotation of a disk and fluid at infinity is studied in this work Exact solutions for velocity and temperature are obtained by using the Laplace transform technique. The performed calculations disclose that the free convection parameter, Prandtl number, radiation parameter, and dimensionless time have strong influence on fluid velocity and temperature. The graphs are presented for such influence and examined carefully.

scholarly journals Free convection flow of micropolar fluids over an oscillating vertical plate

2017 ◽  
Vol 13 (4) ◽  
pp. 654-658 ◽  
Author(s):  
Asma Khalid ◽  
Ilyas Khan ◽  
Sharidan Shafie
Keyword(s):  
Free Convection ◽  
Vertical Plate ◽  
Analytical Investigation ◽  
Convection Flow ◽  
Free Convection Flow ◽  
Micropolar Fluids ◽  
Isothermal Temperature ◽  
Physical Conditions ◽  
Laplace Transform Technique ◽  
The Laplace Transform

An analytical investigation is carried out to study the unsteady free convection flow of micropolar fluids over an oscillating vertical plate. Wall couple stress is engaged at the bounding plate with isothermal temperature. Problem is modelled in terms of coupled partial differential equations together with some physical conditions and then written in non-dimensional form. Exact solutions are obtained using the Laplace transform technique. Analytical results of velocity, microrotation and temperature are plotted in graphs and discussed for various embedded parameters. Excellent validation of present results is achieved with existing results in literature. It is observed that, the velocity is smaller for micropolar fluids than for Newtonian fluids.

Transient free convection flow due to the arbitrary motion of a vertical plate

1970 ◽  
Vol 67 (3) ◽  
pp. 677-688
Author(s):  
P. C. Sinha ◽  
Punyatma Singh
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Vertical Plate ◽  
Fluid Velocity ◽  
Temperature Fields ◽  
Convection Flow ◽  
Free Convection Flow ◽  
Laplace Transform Technique ◽  
The Laplace Transform ◽  
Layer Flow

The paper deals with the free convection flow along a vertical plate moving arbitrarily in its own plane. The basic equations of the boundary-layer flow and heat transfer are linearized and the first two approximations are considered. The first approximation is the case of steady-state free convection flow while the second approximation is the response of the fluid velocity and temperature fields to the motion of the plate for which limiting solutions are obtained by the Laplace transform technique in two regions; namely, for large times and for small times. The particular case when the plate is given an impulsive start at t = 0 is investigated in detail. It is shown how the skin friction and the rate of heat transfer at the plate respond to the motion of the plate.

scholarly journals MASS TRANSFER OF FREE CONVECTION FLOW BETWEEN TWO PARALLEL OSCILLATING PLATES.

2019 ◽  
Vol 1 (2) ◽  
pp. 118-121
Author(s):  
Fasihah Zulkiflee ◽  
Sharidan Shafie ◽  
Ahmad Qushairi Mohamad
Keyword(s):  
Nusselt Number ◽  
Free Convection ◽  
Skin Friction ◽  
Schmidt Number ◽  
Convection Flow ◽  
Parallel Plates ◽  
Governing Equations ◽  
Free Convection Flow ◽  
Laplace Transform Technique ◽  
The Laplace Transform

This paper investigated unsteady free convection flow between two parallel plates with mass diffusion. One of the plate are considered oscillating. Appropriate non-dimensional variables are used to reduce the dimensional governing equations along with imposed initial and boundary conditions. The exact solution for velocity, temperature and concentration profiles are obtained using the Laplace Transform technique. The graphical results of the solutions are presented to illustrate the behavior of the fluid flow with the influenced of Schmidt number, Prandtl number, oscillating parameter, Grashof and mass Grashof number. The corresponding expressions for skin friction, Nusselt number and Sherwood number are also calculated. It is observed that increasing Prandtl and Schmidt number will increased the Nusselt number but decreased the skin friction.

EXACT SOLUTIONS FOR MHD NATURAL CONVECTION FLOW NEAR AN OSCILLATING PLATE EMERGED IN A POROUS MEDIUM

2012 ◽  
Vol 57 (1) ◽  
Author(s):  
ABDULHAMEED MOHAMMED ◽  
ILYAS KHAN ◽  
SHARIDAN SHAFIE
Keyword(s):  
Natural Convection ◽  
Analytical Investigation ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Moving Plate ◽  
Laplace Transform Technique ◽  
Model Equations ◽  
Oscillating Plate ◽  
Special Case ◽  
Infinite Vertical Plate

Analytical investigation was conducted on the transient natural convection flow past an oscillating infinite vertical plate in present of magnetic field and radiative heat transfer. The classical solution of this problem for impulsively moving plate is given by Seth in [2] and is found to be a special case of the solution to be presented. The governing model equations are solved analytically with the help of Laplace transform technique. The results are expressed in terms of the velocity and temperature profiles as well as the skin-friction and Nusselt number.

scholarly journals A Study of Chemically Reactive Species and Thermal Radiation Effects on an Unsteady MHD Free Convection Flow Through a Porous Medium Past a Flat Plate with Ramped Wall Temperature

2017 ◽  
Vol 22 (4) ◽  
pp. 945-964
Author(s):  
K. K. Pandit ◽  
D. Sarma ◽  
S. I. Singh
Keyword(s):  
Porous Medium ◽  
Free Convection ◽  
Thermal Radiation ◽  
Flat Plate ◽  
Radiation Effects ◽  
Fluid Velocity ◽  
Practical Interest ◽  
Convection Flow ◽  
Laplace Transform Technique ◽  
The Laplace Transform

Abstract An investigation of the effects of a chemical reaction and thermal radiation on unsteady MHD free convection heat and mass transfer flow of an electrically conducting, viscous, incompressible fluid past a vertical infinite flat plate embedded in a porous medium is carried out. The flow is induced by a general time-dependent movement of the vertical plate, and the cases of ramped temperature and isothermal plates are studied. An exact solution of the governing equations is obtained in closed form by the Laplace Transform technique. Some applications of practical interest for different types of plate motions are discussed. The numerical values of fluid velocity, temperature and species concentration are displayed graphically whereas the numerical values of skin friction, Nusselt number and Sherwood number are presented in a tabular form for various values of pertinent flow parameters for both ramped temperature and isothermal plates.

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