Radiation effect on heat transfer over a stretching surface

2000 ◽  
Vol 78 (12) ◽  
pp. 1107-1112 ◽  
Author(s):  
E MA Elbashbeshy
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Prandtl Number ◽  
Radiation Effect ◽  
Convection Flow ◽  
Radiation Parameter ◽  
Stretching Surface ◽  
Boundary Layer Equations ◽  
Temperature Parameter ◽  
Forced Convection Flow

We determine the effect of radiation on the forced convection flow of an optically dense incompressible fluid along a heated horizontal stretching surface. The boundary-layer equations are transformed to ordinary differential equations containing a radiation parameter R*, velocity exponent parameter M, Prandtl number P r, and surface temperature parameter θ ω. The effect of these parameters are studied. Graphical results for the velocity and temperature are presented and discussed. PACS Nos.: 44.40+a, 47.27-i

Effects of arbitrary Prandtl number on a forced convection flow near laminar separation

1982 ◽  
Vol 92 (3-4) ◽  
pp. 337-341
Author(s):  
E. A. Akinrelere
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Prandtl Number ◽  
Forced Convection ◽  
Characteristic Length ◽  
Frictional Heating ◽  
Convection Flow ◽  
Laminar Separation ◽  
Thermal Fields ◽  
Forced Convection Flow

SynopsisFollowing an earlier paper by Akinrelere (1981), we consider a laminar boundary layer at low speeds in which density is sensibly constant and frictional heating is neglected. Also following the approach of Goldstein (1948) and Stewartson (1958), a singularity is established at separation for the thermal fields. The heat transfer is determined as a function of ξ = xs – x¼/l where xs is the separation point and l in a characteristic length.The results are for arbitrary Prandtl number σ. The results of Curle (1979) that the heat transfer near separation varies as σ¼ (at least for the first four terms) are confirmed.

scholarly journals The Effect of Plate Oscillations on Horizontal Free Convection Flow

1977 ◽  
Vol 30 (3) ◽  
pp. 335 ◽  
Author(s):  
RL Verma ◽  
Punyatma Singh
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Free Convection ◽  
Skin Friction ◽  
Low Frequency ◽  
Convection Flow ◽  
Phase Lag ◽  
Mean Flow ◽  
Free Convection Flow ◽  
Boundary Layer Equations

The free convection flow along a semi-infinite horizontal plate oscillating in its own plane is analysed The basic flow is purely buoyancy induced, while the oscillations in the plate cause a time-dependent boundary layer flow and heat transfer. The boundary layer equations are linearized and the first two approximations are considered. Two separate solutions valid for high and low frequency ranges are obtained by a series expansion in terms of frequency parameters. The skin friction and the rate of heat transfer are studied for both frequency ranges. For very high frequencies, the oscillatory flow pattern is of a 'shear-wave' type, unaffected by the mean flow. It is found that the phase of the skin friction at the plate lags that of the plate oscillations by in and the rate of heat transfer has a phase lag of 1/2n.

Laminar Boundary∼Layer Free Convection along an Inclined, Isothermal Surface

1972 ◽  
Vol 1 (4) ◽  
pp. 189-196 ◽  
Author(s):  
J.B. Lee ◽  
G.S.H. Lock
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Free Convection ◽  
Laminar Boundary Layer ◽  
Theoretical Consideration ◽  
Plane Surface ◽  
Convection Flow ◽  
Inclined Plane ◽  
Free Convection Flow ◽  
Boundary Layer Equations

This paper gives theoretical consideration to the problem of laminar, boundary-layer, free convection flow along a long, inclined, plane surface heated isothermally. Development of the appropriate boundary-layer equations is followed by their numerical solution for air. The effects of inclination and position on heat transfer and the temperature, pressure and velocity profiles are presented graphically for RaL ≤ 106.

Heat transfer over an unsteady stretching surface in a micropolar fluid in the presence of magnetic field and thermal radiation

2011 ◽  
Vol 89 (3) ◽  
pp. 295-298 ◽  
Author(s):  
D. A. Aldawody ◽  
E. M.A. Elbashbeshy
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Prandtl Number ◽  
Micropolar Fluid ◽  
Material Parameter ◽  
Magnetic Parameter ◽  
Radiation Parameter ◽  
Stretching Surface ◽  
Flow And Heat Transfer ◽  
Unsteady Stretching Surface

The effects of thermal radiation and magnetic field on flow and heat transfer over an unsteady stretching surface in a micropolar fluid are studied. The governing partial differential equations are transformed into a system of ordinary differential equations containing the material parameter K, magnetic parameter M, radiation parameter R, and Prandtl number Pr. These equations are solved numerically by applying a shooting technique, using the Runge–Kutta method. Comparison of the numerical results is made with previously published results under the special cases, and the results are found to be in good agreement. Effects of the material parameter K, magnetic parameter M, radiation parameter R, and Prandtl number Pr on the flow and heat transfer are studied.

Boundary layer flow and melting heat transfer of Prandtl fluid over a stretching surface by considering Joule heating effect

2019 ◽  
Vol 15 (2) ◽  
pp. 337-352 ◽  
Author(s):  
K. Ganesh Kumar ◽  
M.R. Krishnamurthy ◽  
Rudraswamy N.G.
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Boundary Layer Flow ◽  
Stretching Surface ◽  
Content Type ◽  
Melting Heat ◽  
Boundary Layer Equations ◽  
Melting Heat Transfer ◽  
Layer Flow ◽  
Linear Radiation

PurposeThe purpose of this paper is to study the impact of Joule heating on boundary layer flow and melting heat transfer of Prandtl fluid over a stretching sheet in the presence of fluid particles suspension. The transformed boundary layer equations are solved numerically by RKF-45 method. The influence of the non-dimensional parameters on velocity and temperature growths in the boundary layer region is analyzed in detail and the results are shown graphically. The results indicate that the larger estimation ofαandβreduces for both velocity and temperature profile. Further, the rate of heat transfer decreases by increasing melting parameter.Design/methodology/approachThe converted set of boundary layer equations is solved numerically by RKF-45 method. Obtained numerical results for flow and heat transfer characteristics are deliberated for various physical parameters. Furthermore, the skin friction coefficient and Nusselt number are also presented.FindingsIt is found that the heat transfer rates are advanced in the occurrence of non-linear radiation camper to linear radiation. Also, it is noticed that velocity profile increases by increasing Prandtl parameter but establishes opposite results for temperature profile.Originality/valueThe authors intend to analyze the boundary layer flow and melting heat transfer of a Prandtl fluid over a stretching surface in the presence of fluid particles suspension. The governing systems of partial differential equations have been transformed to a set of coupled ordinary differential equations by applying appropriate similarity transformations. The reduced equations are solved numerically. The pertinent parameters are discussed through graphs and plotted graphs. The present results are compared with the existing limiting solutions, showing good agreement with each other.

scholarly journals Forced convection heat transfer of Casson fluid in non-Darcy porous media

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401881990 ◽  
Author(s):  
Bashar R Qawasmeh ◽  
Mohammad Alrbai ◽  
Sameer Al-Dahidi
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Porous Media ◽  
Prandtl Number ◽  
Forced Convection ◽  
Local Heat Transfer ◽  
Casson Fluid ◽  
Local Skin ◽  
Transfer Rates ◽  
Boundary Layer Equations

Forced convection of non-Newtonian Casson fluid laminar boundary layer flow past an isothermal horizontal flat plate in non-Darcy porous media is studied using Darcy–Forchheimer–Brinkman model. Similarity variables are used to transform the boundary layer equations. The boundary layer equations are reduced into system of first-order differential equations using similarity method. Then, solved numerically using adaptive Runge–Kutta–Fehlberg scheme simultaneously with shooting technique. The effects of Casson parameter, porosity, first- and second-order porous resistances, and Prandtl number on the fluid flow and heat transfer are investigated in terms of the local skin friction and local heat transfer parameters. In addition, velocity and temperature boundary layer profiles are plotted for all considered parameters. It is found that the heat transfer could be enhanced by increasing the Casson parameter and the porous resistance terms. To the contrary, the increase in the porosity reduces heat transfer rates. Finally, the increase in the Prandtl number enhances the heat transfer rates.

Integration of the boundary-layer equations for a plane in compressible flow with heat transfer

1955 ◽  
Vol 231 (1185) ◽  
pp. 274-280 ◽  
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Prandtl Number ◽  
Pressure Gradient ◽  
Drag Coefficient ◽  
Compressible Flow ◽  
Equations Of Motion ◽  
Main Flow ◽  
Physical Constants ◽  
Boundary Layer Equations

The equations of motion of compressible viscous flow with vanishing pressure gradient past a plane are integrated in semi-convergent expressions, for the case when the physical constants depend on temperature and the Prandtl number σ is close to unity. Simple expressions are obtained for the temperature and velocity distributions in the boundary layer, the drag coefficient, and their dependence on the physical constants; they contain the well-known results and several new ones. For the case when the temperature of the boundary is either above, or not much below, the temperature of the main flow, the results obtained closely agree with Crocco’s numerical computations.

Effect of Nanofluid on Heat Transfer Enhancement for Mixed Convection Flow Over a Corrugated Surface

2020 ◽  
Vol 45 (4) ◽  
pp. 373-383
Author(s):  
Nepal Chandra Roy ◽  
Sadia Siddiqa
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Nusselt Number ◽  
Mixed Convection ◽  
Local Nusselt Number ◽  
Richardson Number ◽  
Thermal Boundary Layer ◽  
Volume Fraction ◽  
Convection Flow ◽  
Mixed Convection Flow

AbstractA mathematical model for mixed convection flow of a nanofluid along a vertical wavy surface has been studied. Numerical results reveal the effects of the volume fraction of nanoparticles, the axial distribution, the Richardson number, and the amplitude/wavelength ratio on the heat transfer of Al2O3-water nanofluid. By increasing the volume fraction of nanoparticles, the local Nusselt number and the thermal boundary layer increases significantly. In case of \mathrm{Ri}=1.0, the inclusion of 2 % and 5 % nanoparticles in the pure fluid augments the local Nusselt number, measured at the axial position 6.0, by 6.6 % and 16.3 % for a flat plate and by 5.9 % and 14.5 %, and 5.4 % and 13.3 % for the wavy surfaces with an amplitude/wavelength ratio of 0.1 and 0.2, respectively. However, when the Richardson number is increased, the local Nusselt number is found to increase but the thermal boundary layer decreases. For small values of the amplitude/wavelength ratio, the two harmonics pattern of the energy field cannot be detected by the local Nusselt number curve, however the isotherms clearly demonstrate this characteristic. The pressure leads to the first harmonic, and the buoyancy, diffusion, and inertia forces produce the second harmonic.

Unsteady Natural Convection Heat Transfer Past a Vertical Flat Plate Embedded in a Porous Medium Saturated With Fractional Oldroyd-B Fluid

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Jinhu Zhao ◽  
Liancun Zheng ◽  
Xinxin Zhang ◽  
Fawang Liu ◽  
Xuehui Chen
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Porous Medium ◽  
Natural Convection ◽  
Prandtl Number ◽  
Fractional Derivative ◽  
Convection Heat Transfer ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Elastic Effect

This paper investigates natural convection heat transfer of generalized Oldroyd-B fluid in a porous medium with modified fractional Darcy's law. Nonlinear coupled boundary layer governing equations are formulated with time–space fractional derivatives in the momentum equation. Numerical solutions are obtained by the newly developed finite difference method combined with L1-algorithm. The effects of involved parameters on velocity and temperature fields are presented graphically and analyzed in detail. Results indicate that, different from the classical result that Prandtl number only affects the heat transfer, it has remarkable influence on both the velocity and temperature boundary layers, the average Nusselt number rises dramatically in low Prandtl number, but increases slowly with the augment of Prandtl number. The maximum value of velocity profile and the thickness of momentum boundary layer increases with the augment of porosity and Darcy number. Moreover, the relaxation fractional derivative parameter accelerates the convection flow and weakens the elastic effect significantly, while the retardation fractional derivative parameter slows down the motion and strengthens the elastic effect.

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