Transient Free Convection Flow Past an Infinite Moving Vertical Cylinder in a Stably Stratified Fluid

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
R. K. Deka ◽  
A. Paul
Keyword(s):  
Nusselt Number ◽  
Steady State ◽  
Skin Friction ◽  
Thermal Stratification ◽  
Fluid Velocity ◽  
Vertical Cylinder ◽  
Convection Flow ◽  
Physical Parameters ◽  
Flow Past ◽  
Laplace Transform Technique

This paper presents an analytical treatment for the unsteady one-dimensional natural convective flow past an infinite moving vertical cylinder in the presence of thermal stratification. Exact solutions of the dimensionless unsteady coupled linear governing equations are obtained, in terms of Bessel functions by the Laplace transform technique, for the tractable case of unit Prandtl number. Numerical computations for velocity, temperature, skin-friction, and Nusselt number are made for various set of physical parameters and presented in graphs. Due to the presence of thermal stratification, the fluid velocity and temperature approach steady state, whereas the corresponding flow in an unstratified fluid does not. The steady state is attained at smaller times as the stratification increases. Furthermore, in the presence of stratification, the skin-friction and Nusselt number approaches fixed value as time progresses, while for unstratified fluid, there is a gradual decrease as time increases.

Unsteady free convection flow past a periodically accelerated vertical plate with Newtonian heating

2016 ◽  
Vol 26 (7) ◽  
pp. 2119-2138 ◽  
Author(s):  
M.C. Raju ◽  
S.V.K. Varma ◽  
A.J. Chamkha
Keyword(s):  
Mass Transfer ◽  
Free Convection ◽  
Skin Friction ◽  
Heat And Mass Transfer ◽  
Convection Flow ◽  
Convection Boundary Layer ◽  
Physical Parameters ◽  
Content Type ◽  
Flow Past ◽  
Laplace Transform Technique

Purpose The purpose of this paper is to present an analytical study for a problem of unsteady free convection boundary layer flow past a periodically accelerated vertical plate with Newtonian heating (NH). Design/methodology/approach The equations governing the flow are studied in the closed form by using the Laplace transform technique. The effects of various physical parameters are studied through graphs and the expressions for skin friction, Nusselt number and Sherwood number are also derived and discussed numerically. Findings It is observed that velocity, concentration and skin friction decrease with the increasing values of Sc whereas temperature distribution decreases in the increase in Pr in the presence of NH. Research limitations/implications This study is limited to a Newtonian fluid. This can be extended for non-Newtonian fluids. Practical implications Heat and mass transfer frequently occurs in chemically processed industries, distribution of temperature and moisture over agricultural fields, dispersion of fog and environment pollution and polymer production. Social implications Free convection flow of coupled heat and mass transfer occurs due to the temperature and concentration differences in the fluid as a result of driving forces. For example, in atmospheric flows, thermal convection resulting from heating of the earth by sunlight is affected differences in water vapor concentration. Originality/value The authors have studied heat and mass transfer effects on unsteady free convection boundary layer flow past a periodically accelerated vertical surface with NH, where the heat transfer rate from the bounding surface with a finite heat capacity is proportional to the local surface temperature, and which is usually termed as conjugate convective flow. The equations governing the flow are studied in the closed form by using the Laplace transform technique. The effects of various physical parameters are studied through graphs and the expression for skin friction also derived and discussed.

scholarly journals EFFECT OF HEAT AND MASS TRANSFER AND THERMAL RADIATION ON A STEADY MHD CONVECTIVE FLOW WITH VISCOUS DISSIPATION AND SUCTION/INJECTION

2022 ◽  
Vol 52 (1) ◽  
pp. 35-41
Author(s):  
Silpisikha Goswami ◽  
Kamalesh Kumar Pandit ◽  
Dipak Sarma
Keyword(s):  
Nusselt Number ◽  
Thermal Radiation ◽  
Temperature Profile ◽  
Skin Friction ◽  
Viscous Dissipation ◽  
Sherwood Number ◽  
Fluid Velocity ◽  
Physical Parameters ◽  
Flow Equations ◽  
The Impact

Our motive is to examine the impact of thermal radiation and suction or injection with viscous dissipation on an MHD boundary layer flow past a vertical porous stretched sheet immersed in a porous medium. The set of the flow equations is converted into a set of non-linear ordinary differential equations by using similarity transformation. We use Runge Kutta method and shooting technique in MATLAB Package to solve the set of equations. The impact of non-dimensional physical parameters on flow profiles is analysed and depicted in graphs. We observe the influence of non-dimensional physical quantities on the Nusselt number, the Sherwood number, and skin friction and presented in tables. A comparison of the obtained numerical results with existing results in a limiting sense is also presented. We enhance radiation to observe the deceleration of fluid velocity and temperature profile for both suction and injection. While enhancing porosity parameter accelerates velocity whereas decelerates temperature profile. As the heat source parameter increases, the temperature of the fluid decreases for both suction and injection, it has been found. With the increasing values of the radiation parameter, the skin friction and heat transfer rate decreases. Increasing magnetic parameter decelerates the skin friction, Nusselt number, and Sherwood number.

The Effects of Radiation on Free Convection Flow with Ramped Wall Temperature in Brinkman Type Fluid

2013 ◽  
Vol 62 (3) ◽  
Author(s):  
Muhamad Najib Zakaria ◽  
Abid Hussanan ◽  
Ilyas Khan ◽  
Sharidan Shafie
Keyword(s):  
Nusselt Number ◽  
Free Convection ◽  
Laplace Transform ◽  
Vertical Plate ◽  
Convection Flow ◽  
Physical Parameters ◽  
Governing Equations ◽  
Free Convection Flow ◽  
Laplace Transform Technique ◽  
Effects Of Radiation

The present paper is on study of the influence of radiation on unsteady free convection flow of Brinkman type fluid near a vertical plate containing a ramped temperature profile. Using the appropriate variables, the basic governing equations are reduced to nondimensional equations valid with the imposed initial and boundary conditions. The exact solutions are obtained by using Laplace transform technique. The influence of radiation near a ramped temperature plate is also compared with the flow near a plate with constant temperature. The numerical computations are carried out for various values of the physical parameters such as velocity, temperature, skin friction and Nusselt number and presented graphically.

scholarly journals Unsteady Free Convection Flow between Two Vertical Parallel Plates with Newtonian Heating

MATEMATIKA ◽  
2019 ◽  
Vol 35 (2) ◽  
pp. 117-127
Author(s):  
Fasihah Zulkiflee ◽  
Ahmad Qushairi Mohamad ◽  
Sharidan Shafie ◽  
Arshad Khan
Keyword(s):  
Nusselt Number ◽  
Free Convection ◽  
Skin Friction ◽  
Approximate Solutions ◽  
Convection Flow ◽  
Parallel Plates ◽  
Newtonian Heating ◽  
Free Convection Flow ◽  
Laplace Transform Technique ◽  
Incompressible Viscous Fluids

Free convection flow in a boundary layer region is a motion that results from the interaction of gravity with density differences within a fluid. These differences occur due to temperature or concentration gradients or due to their composition. Studies pertaining free convection flows of incompressible viscous fluids have received much attention in recent years both theoretically (exact or approximate solutions) and experimentally. The situation where the heat be transported to the convective fluid via a bounding surface having finite heat capacity is known as Newtonian heating (or conjugate convective flows). In this paper, the unsteady free convection flow of an incompressible viscous fluid between two parallel plates with Newtonian heating is studied. Appropriate non-dimensional variables are used to reduce the dimensional governing equations along with imposed initial and boundary conditions into dimensionless forms. The exact solutionsfor velocity and temperature are obtained using the Laplace transform technique. The corresponding expressions for skin friction and Nusselt number are also calculated. The graphical results are displayed to illustrate the influence of various embedded parameters such as Newtonian heating parameter and Grashof number. The results show that the effect of Newtonian heating parameter increases the Nusselt number but reduces the skin friction.

MHD Free Convection Flow Past an Impulsively Started Infinite Vertical Plate With Thermal Stratification and Radiation

2012 ◽  
Author(s):  
Rudra Kt. Deka ◽  
Bhaben Ch. Neog
Keyword(s):  
Thermal Stratification ◽  
Vertical Plate ◽  
Fluid Velocity ◽  
Transverse Magnetic ◽  
Convection Flow ◽  
Flow Past ◽  
The One ◽  
Technique Comparison ◽  
Unsteady Natural Convection ◽  
Infinite Vertical Plate

An exact solution to the one-dimensional unsteady natural convection flow past an impulsively started infinite vertical plate with combined effect of thermal stratification and radiation under the influence of transverse magnetic field is presented. The solutions for fluid velocity, temperature are obtained by the Laplace transformation technique. Comparison is made between the solutions with and without thermal stratification and the differences in both the cases are presented graphically. Comparison reveals that thermal stratification has significant impact on convection flow past vertical plates on radiating MHD flows.

scholarly journals Chemical Reaction Effect on Transient Free Convective Flow past an Infinite Moving Vertical Cylinder

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Ashish Paul ◽  
Rudra Kanta Deka
Keyword(s):  
Chemical Reaction ◽  
Sherwood Number ◽  
Vertical Cylinder ◽  
Physical Parameters ◽  
Grashof Number ◽  
Closed Form Solutions ◽  
Flow Past ◽  
Laplace Transform Technique ◽  
The Laplace Transform ◽  
First Order Chemical Reaction

An analysis is performed to study the heat and mass transfer on the flow past an infinite moving vertical cylinder, in the presence of first-order chemical reaction. The closed-form solutions of the dimensionless governing partial differential equations are obtained in terms of Bessel's functions and modified Bessel's functions by the Laplace transform technique. The transient velocity profiles, temperature profiles, and concentration profiles are studied for various sets of physical parameters, namely, the chemical reaction parameter, Prandtl number, Schmidt number, thermal Grashof number, mass Grashof number, and time. The skin friction, Nusselt number, and Sherwood number are also obtained and presented in graphs. It is observed that in presence of as well as increase in chemical reaction the flow velocity decreases. Also, in presence of destructive chemical reaction the concentration profile and Sherwood number tend to the steady state at large time.

scholarly journals Unsteady Natural Convection Flow past an Infinite Cylinder with Thermal and Mass Stratification

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Ashish Paul ◽  
Rudra Kanta Deka
Keyword(s):  
Schmidt Number ◽  
Infinite Cylinder ◽  
Convection Flow ◽  
Physical Parameters ◽  
Free Convection Flow ◽  
Fluid Medium ◽  
Flow Past ◽  
Laplace Transform Technique ◽  
Mass Stratification ◽  
Unsteady Natural Convection

This paper presents an analytical solution of unsteady one-dimensional free convection flow past an infinite vertical circular cylinder in a stratified fluid medium. The dimensionless coupled linear governing partial differential equations are solved by Laplace transform technique for unit Prandtl number and Schmidt number. Effects of various physical parameters are presented with graphs. Numerical values of boundary layer thickness for different parameters are presented in table. Due to the effects of thermal and mass stratifications, the velocity, temperature, and skin friction, Nusselt number shows oscillatory behaviour at smaller times and then reaches steady state at larger times.

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.

scholarly journals Thermo-diffusion effects on the magnetohydrodynamic natural convection flow of a chemically reactive Brinkman type nanofluid in a porous medium

2019 ◽  
Vol 51 (2) ◽  
pp. 168-179 ◽  
Author(s):  
G. S. Seth ◽  
R. Kumar ◽  
R. Tripathi
Keyword(s):  
Natural Convection ◽  
Skin Friction ◽  
Fluid Velocity ◽  
Surface Concentration ◽  
Convection Flow ◽  
Fluid Temperature ◽  
Species Concentration ◽  
Electrically Conducting ◽  
Laplace Transform Technique ◽  
Mass Transfers

An investigation on the unsteady MHD natural convection heat and mass transfer flow of an electrically conducting, viscous, incompressible, chemically reactive and heat-absorbing nanofluid of Brinkman type past an exponentially accelerated moving vertical plate with ramped wall temperature and ramped surface concentration is carried out. Governing equations are non-dimensionalized and Laplace Transform Technique is used to find the exact solutions for fluid velocity, fluid temperature and species concentration. The quantities of physical interest, i.e. skin friction, rates of heat and mass transfers at the plate are also calculated. Numerical results for the velocity, temperature and species concentration of the fluid are demonstrated with the help of graphs whereas those of skin friction, rate of heat and mass transfers at the plate are displayed in tables for various flow parameters.

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