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1.
The steady nonlinear hydromagnetic flow of an incompressible, viscous and electrically conducting fluid with heat transfer over a surface of variable temperature stretching with a power-law velocity in the presence of variable transverse magnetic field is analysed. Utilizing similarity transformation, governing nonlinear partial differential equations are transformed to nonlinear ordinary differential equations and they are numerically solved using fourth-order Runge–Kutta shooting method. Numerical solutions are illustrated graphically by means of graphs. The effects of magnetic field, stretching parameter and Prandtl number on velocity, skin friction, temperature distribution and rate of heat transfer are discussed. 相似文献
2.
The effect of melting heat transfer on the two dimensional boundary layer flow of a micropolar fluid near a stagnation point embedded in a porous medium in the presence of internal heat generation/absorption is investigated. The governing non-linear partial differential equations describing the problem are reduced to a system of non-linear ordinary differential equations using similarity transformations solved numerically using the Chebyshev spectral method. Numerical results for velocity, angular velocity and temperature profiles are shown graphically and discussed for different values of the inverse Darcy number, the heat generation/absorption parameter, and the melting parameter. The effects of the pertinent parameters on the local skin-friction coefficient, the wall couple stress, and the local Nusselt number are tabulated and discussed. The results show that the inverse Darcy number has the effect of enhancing both velocity and temperature and suppressing angular velocity. It is also found that the local skin-friction coefficient decreases, while the local Nusselt number increases as the melting parameter increases. 相似文献
3.
The steady laminar boundary layer flow and heat transfer past a stretching sheet arre considered. Upper‐convected Maxwell (UCM) fluid is treated as a rheological model. The resulting nonlinear differential system is solved by homotopy analysis method (HAM). The influence of melting parameter (M), Prandtl number (Pr), Deborah number (β) and stretching ratio (A = a/c) on the velocity and temperature profiles is thoroughly examined. It is noticed that fields are effected appreciably with the variation of parameters. Furthermore, it is seen that the local Nusselt number is a decreasing function of melting parameter. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
4.
《应用数学和力学(英文版)》2019,(4)
This paper investigates the unsteady stagnation point flow and heat transfer of magnetohydrodynamic(MHD) fluids over a moving permeable flat surface. The unsteady Navier-Stokes(NS) equations are transformed into a similarity nonlinear ordinary differential equation, and a closed form solution is obtained for the unsteadiness parameter of 2. The boundary layer energy equation is transformed into a similarity equation,and is solved for a constant wall temperature and a time-dependent uniform wall heat flux case. The solution domain, velocity, and temperature profiles are calculated for different combinations of parameters including the Prandtl number, mass transfer parameter, wall moving parameter, and magnetic parameter. Two solution branches are obtained for certain combinations of the controlling parameters, and a stability analysis demonstrates that the lower solution branch is not stable. The present solutions provide an exact solution to the entire unsteady MHD NS equations, which can be used for validating the numerical code of computational fluid dynamics. 相似文献
5.
In this paper we present a mathematical analysis of heat and mass transfer phenomena in a visco–elastic fluid flow over an
accelerating stretching sheet in the presence of heat source/sink, viscous dissipation and suction/blowing. Similarity transformations
are used to convert highly non-linear partial differential equations into ordinary differential equations. Several closed
form analytical solutions for non-dimensional temperature, concentration, heat flux, mass flux profiles are obtained in the
form of confluent hypergeometric (Kummer's) functions for two different cases of the boundary conditions, namely, (i) wall
with prescribed second order power law temperature and second order power law concentration (PST), and (ii) wall with prescribed
second order power law heat flux and second order power law mass flux (PHF). The effect of various physical parameters like
visco–elasticity, Eckert number, Prandtl number, heat source/sink, Schmidt number and suction/blowing parameter on temperature
and concentration profiles are analysed. The effects of all these parameters on wall temperature gradient and wall concentration
gradient are also discussed.
Received on 23 March 2000 / Published online: 29 November 2001 相似文献
6.
Mixed convection heat transfer about a semi-infinite inclined plate in the presence of magneto and thermal radiation effects
is studied. The fluid is assumed to be incompressible and dense. The nonlinear coupled parabolic partial differential equations
governing the flow are transformed into the non-similar boundary layer equations, which are then solved numerically using
the Keller box method. The effects of the mixed convection parameter R
i, the angle of inclination α, the magnetic parameter M and the radiation–conduction parameter R
d on the velocity and temperature profiles as well as on the local skin friction and local heat transfer parameters. For some
specific values of the governing parameters, the results are compared with those available in the literature and a fairly
good agreement is obtained. 相似文献
7.
Network simulation method(NSM) is used to solve the laminar heat and mass transfer of an electricallyconducting,heat generating/absorbing fluid past a perforated horizontal surface in the presence of viscous and Joule heating problem. The governing partial differential equations are non-dimensionalized and transformed into a system of nonlinear ordinary differential similarity equations,in a single independent variable,η. The resulting coupled,nonlinear equations are solved under appropriate transformed boundary conditions. Computations are performed for a wide range of the governing flow parameters,viz Prandtl number,thermophoretic coeffcient(a function of Knudsen number),thermal conductivity parameter,wall transpiration parameter and Schmidt number. The numerical details are discussed with relevant applications. The present problem finds applications in optical fiber fabrication,aerosol filter precipitators,particle deposition on hydronautical blades,semiconductor wafer design,thermo-electronics and problems including nuclear reactor safety. 相似文献
8.
Effects of Chemical Reaction and Double Dispersion on Non-Darcy Free Convection Heat and Mass Transfer 总被引:1,自引:0,他引:1
In this article, the effects of chemical reaction and double dispersion on non-Darcy free convection heat and mass transfer
from semi-infinite, impermeable vertical wall in a fluid saturated porous medium are investigated. The Forchheimer extension
(non-Darcy term) is considered in the flow equations, while the chemical reaction power–law term is considered in the concentration
equation. The first order chemical reaction (n = 1) was used as an example of calculations. The Darcy and non-Darcy flow, temperature and concentration fields in this study
are observed to be governed by complex interactions among dispersion and natural convection mechanisms. The governing set
of partial differential equations were non-dimensionalized and reduced to a set of ordinary differential equations for which
Runge–Kutta-based numerical technique were implemented. Numerical results for the detail of the velocity, temperature, and
concentration profiles as well as heat transfer rates (Nusselt number) and mass transfer rates (Sherwood number) are presented
in graphs. 相似文献
9.
The present contribution deals with the thermophoresis particle deposition and thermal radiation effects on the flow, heat
and mass transfer characteristics in a viscous fluid over a semi-infinite vertical porous plate. The governing boundary layer
equations are written into a dimensionless form by similarity transformations. The transformed coupled nonlinear ordinary
differential equations are solved numerically by means of the fourth-order Runge–Kutta method with a shooting technique. The
effects of different parameters on the dimensionless velocity, temperature, and concentration profiles are shown graphically.
In addition, results for the local skin-friction coefficient, the local Nusselt number, and the local Sherwood number are
tabulated and discussed. 相似文献
10.
H. Tamim S. Dinarvand R. Hosseini H. Rahimi I. Pop 《Journal of Applied Mechanics and Technical Physics》2016,57(6):1031-1041
A similarity solution for a steady laminar mixed convection boundary layer flow of a nanofluid near the stagnation point on a vertical permeable plate with a magnetic field and a buoyancy force is obtained by solving a system of nonlinear ordinary differential equations. These equations are solved analytically by using a new kind of a powerful analytic technique for nonlinear problems, namely, the homotopy analysis method (HAM). Three different types of nanoparticles, namely, copper (Cu), alumina (Al2O3), and titanium oxide (TiO2), with water as the base fluid are considered. The influence of the volume fraction of nanoparticles, permeability parameter, magnetic parameter, and mixed convection parameter on the surface shear stress and surface heat transfer, as well as on the velocity and temperature profiles, is considered. It is observed that the skin friction coefficient and the local Nusselt number increase with the nanoparticle volume fraction for all types of nanoparticles considered in this study. The greatest values of the skin friction coefficient and the local Nusselt number are obtained for Cu nanoparticles. 相似文献
11.
Similarity solution of the laminar boundary layer equations corresponding to an unsteady stretching surface have been studied. The governing time-dependent boundary layer are transformed to ordinary differential equations containg Prandtl number and unsteadiness parameter. The effect of various govern-ing parameters such as Prandtl number and unsteadiness param-eter which determine the velocity and temperature profiles and heat transfer coefficient are studied. 相似文献
12.
The problem of the flow and heat transfer over an unsteady stretching sheet embedded in a porous medium in the presence of thermal radiation is studied theoretically and numerically. The continuity, momentum, and energy equations, which are coupled nonlinear partial differential equations, are reduced to a set of two nonlinear ordinary differential equations. Special attention is given to study the convergence of the proposed method. The error estimation is also given. The effects of various parameters, such as the Darcy parameter, the radiation parameter, and the Prandtl number, on the flow and temperature profiles, as well as on the local skin-friction coefficient and the local Nusselt number are presented and discussed. The results obtained agree very well with the data obtained by the Runge-Kutta method coupled with the shooting technique. 相似文献
13.
This investigation explores the characteristics of melting heat transfer in a boundary layer flow of the Jeffrey fluid near the stagnation point on a stretching sheet subject to an applied magnetic field. The governing boundary layer equations are transformed to ordinary differential equations by similarity transformations. Resulting nonlinear problems are solved analytically by the homotopy analysis method. It is noticed that an increase in the melting parameter decreases the dimensionless velocity and temperature, while an increase in the Deborah number increases the velocity and momentum boundary layer thickness. 相似文献
14.
The present paper deals with the study of heat transfer characteristics in the laminar boundary layer flow of an incompressible
viscous fluid over an unsteady stretching sheet which is placed in a porous medium in the presence of viscous dissipation
and internal absorption or generation. Similarity transformations are used to convert the governing time dependent nonlinear
boundary layer equations into a system of non-linear ordinary differential equations containing Prandtl number, Eckert number,
heat source/sink parameter, porous parameter and unsteadiness parameter with appropriate boundary conditions. These equations
are solved numerically by applying shooting method using Runge-Kutta-Fehlberg method. Comparison of numerical results is made
with the earlier published results under limiting cases. The effects of the parameters which determine the velocity and temperature
fields are discussed in detail. 相似文献
15.
In this paper, the problem of free convection boundary layer flow on a solid sphere in a micropolar fluid with Newtonian heating,
in which the heat transfer from the surface is proportional to the local surface temperature, is considered. The transformed
boundary layer equations in the form of partial differential equations are solved numerically using an implicit finite-difference
scheme. Numerical solutions are obtained for the local wall temperature, the local skin friction coefficient, as well as the
velocity, angular velocity and temperature profiles. The features of the flow and heat transfer characteristics for different
values of the material or micropolar parameter K, the Prandtl number Pr and the conjugate parameter γ are analyzed and discussed. 相似文献
16.
Entropy generation due to fluid flow and heat transfer inside a horizontal channel made of two parallel plates under the effect
of transverse magnetic field is numerically investigated. The flow is assumed to be steady, laminar, hydro-dynamically and
thermally fully developed of electrically conducting fluid. Both horizontal walls are maintained at constant temperatures
higher than that of the fluid. The governing equations in Cartesian coordinate are solved by an implicit finite difference
technique. After the flow field and the temperature distributions are obtained, the entropy generation profiles are computed
and presented graphically. The factors, which were found to affect the problem under consideration are the magnetic parameter,
Eckert number, Prandtl number, and the temperature parameter (θ∞). It was found that, entropy generation increased as all parameters involved in the present problem increased. 相似文献
17.
This article investigates a theoretical and numerical study for the effect of viscous dissipation on the steady flow with heat transfer of Newtonian fluid toward a permeable stretching surface embedded in a porous medium with a second-order slip and thermal slip. The governing nonlinear partial differential equations are converted into nonlinear ordinary differential equations (ODEs) using similarity variables. The resulting ODEs are successfully solved numerically with the help of Chebyshev finite difference method. Graphically results are shown for non-dimensional velocities and temperature. The effects of the porous parameter, the suction (injection) parameter, Eckert number, first- and second-order velocity slip parameter, the thermal slip parameter and the Prandtl number on the flow and temperature profiles are presented. Moreover, the local skin-friction and Nusselt numbers are presented. A comparison of numerical results is made with the earlier published results under limiting cases. 相似文献
18.
A numerical study is carried out for the axisymmetric steady laminar incompressible flow of an electrically conducting micropolar fluid between two infinite parallel porous disks with the constant uniform injection through the surface of the disks. The fluid is subjected to an external transverse magnetic field. The governing nonlinear equations of motion are transformed into a dimensionless form through von Karman’s similarity transformation. An algorithm based on a finite difference scheme is used to solve the reduced coupled ordinary differential equations under associated boundary conditions. The effects of the Reynolds number, the magnetic parameter, the micropolar parameter, and the Prandtl number on the flow velocity and temperature distributions are discussed. The results agree well with those of the previously published work for special cases. The investigation predicts that the heat transfer rate at the surfaces of the disks increases with the increases in the Reynolds number, the magnetic parameter, and the Prandtl number. The shear stresses decrease with the increase in the injection while increase with the increase in the applied magnetic field. The shear stress factor is lower for micropolar fluids than for Newtonian fluids, which may be beneficial in the flow and thermal control in the polymeric processing. 相似文献
19.
M. Chandrasekar 《Heat and Mass Transfer》2003,40(1-2):157-165
The Governing Principle of Dissipative Processes (GPDP) formulated by Gyarmati into non-equilibrium thermodynamics is employed
to study the effects of heat transfer, two dimensional, laminar and constant property fluid flow in the boundary layer with
suction and injection. The flow and temperature fields inside the boundary layer are approximated by simple third degree polynomial
functions and the variational principle is formulated over the region of the boundary layer. The Euler–Lagrange equations
of the principle are obtained as polynomial equations in terms of momentum and thermal layer thicknesses. These equations
are solvable for any given values of Prandtl number Pr, wedge angle parameter m and suction/injection parameter H. The obtained
analytical solutions are compared with known numerical solutions and the comparison shows the fact that the accuracy is remarkable. 相似文献
20.
A. MASTROBERARDINO 《应用数学和力学(英文版)》2013,34(9):1043-1054
The steady, laminar, incompressible flow and heat transfer of a viscous fluid between two circular cylinders for two different types of thermal boundary conditions are investigated. The governing Navier-Stokes and thermal equations of the flow are reduced to a nonlinear system of ordinary differential equations. The equations are solved analyt- ically using the homotopy analysis method (HAM). Convergence of the HAM solutions is discussed in detail. These solutions are then compared with recently obtained numericM and perturbative solutions. Plots of the velocity and temperature profiles are provided for various values of the relevant parameters. 相似文献