Maxwell Fluids Unsteady Mixed Flow and Radiation Heat Transfer Over a Stretching Permeable Plate With Boundary Slip and Nonuniform Heat Source/Sink

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Liancun Zheng ◽  
Ning Liu ◽  
Xinxin Zhang
Keyword(s):  
Heat Transfer ◽  
Differential Equations ◽  
Heat Source ◽  
Mixed Boundary ◽  
Radiation Heat Transfer ◽  
Radiation Heat ◽  
Boundary Slip ◽  
Analytical Approximations ◽  
Maxwell Fluids ◽  
Source Sink

This paper presents an analysis for the unsteady mixed boundary-layer flow and radiation heat transfer of generalized Maxwell fluids toward an unsteady stretching permeable surface in presence of boundary slip and nonuniform heat source/sink. The governing partial differential equations are converted into nonlinear ordinary differential equations and analytical approximations of solutions are derived by homotopy analysis method (HAM). The effects of the unsteadiness parameter, nonuniform heat source/sink parameter, suction/injection parameter, thermal radiation parameter and slip parameter on the fluid flow, and heat transfer characteristics are shown graphically and analyzed.

scholarly journals Effects of Mass Suction on MHD Boundary Layer Flow and Heat Transfer over a Porous Shrinking Sheet with Heat Source/Sink

2019 ◽  
Vol 8 (10) ◽  
pp. 263-266 ◽  
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Boundary Layer ◽  
Differential Equations ◽  
Heat Source ◽  
Ordinary Differential Equations ◽  
Shrinking Sheet ◽  
Dynamic Framework ◽  
Mhd Boundary Layer ◽  
Source Sink

An examination is made to think about the impacts of the mass suction on the steady flow of 2-D magneto-hydrodynamic (MHD) boundary layer flows and heat transfer past on a shrinking sheet with source/sink. In the dynamic framework, an-uniform magnetic field acts perpendicular to the plane of flow. The governing non-dimensional partial differential equations are changed into nonlinear ordinary differential equations (ODE’s) using similarity transformations. The so derived ordinary differential equations are solved numerically by using the MAT LAB solver bvp5c. From the keen examinations it is found that the velocity inside the boundary layer increments with increment of wall mass suction, magnetic field and reportedly the thickness of the momentum layer diminishes. There is a reduction in temperature as increases the Prandtl number. With heat source specifications, Hartmann number, heat sink parameter & the temperature increments are seen. Moreover, for strong heat source heat assimilation at the sheet happens.

Combined Natural Convection–Conduction and Radiation Heat Transfer in a Discretely Heated Open Cavity

1996 ◽  
Vol 118 (1) ◽  
pp. 56-64 ◽  
Author(s):  
A. A. Dehghan ◽  
M. Behnia
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Heat Source ◽  
Radiation Heat Transfer ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Radiation Heat ◽  
Transfer Coefficients ◽  
Thermal Fields ◽  
Discrete Heat Source

Combined natural convection, conduction, and radiation heat transfer in an open-top upright cavity containing a discrete heat source has been modeled numerically. The surface emissivity has been varied and its effects on the flow and thermal fields have been determined for different values of Rayleigh number. The complex interaction of the three modes of heat transfer mechanisms is explored by solving the coupled convection, conduction, and radiation equations. It is noted that the inclusion of radiation has a significant effect on the flow, resulting in the formation of a recirculation zone within the cavity. Comparison of the local heat transfer coefficients for the conjugate analysis and no radiation case reveals that the inclusion of radiation has a negligible effect on the heat transfer performance of the heat source. However, comparison of the numerical results with experimental observations shows that accurate prediction of the flow and thermal fields is strongly dependent on the consideration of radiation heat transfer in the numerical case.

Development of hybrid method for coupled conduction-radiation heat transfer in two-dimensional irregular enclosure considering thermo-radiative effects and varying thermal conductivity

2019 ◽  
Vol 30 (4) ◽  
pp. 1815-1837
Author(s):  
Mehdi Zare ◽  
Sadegh Sadeghi
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Flux ◽  
Heat Source ◽  
Radiation Heat Transfer ◽  
Isotropic Scattering ◽  
Two Dimensional ◽  
Radiation Heat ◽  
Content Type ◽  
Irregular Enclosure

Purpose This study aims to perform a comprehensive investigation to model the thermal characteristics of a coupled conduction-radiation heat transfer in a two-dimensional irregular enclosure including a triangular-shaped heat source. Design/methodology/approach For this purpose, a promising hybrid technique based on the concepts of blocked-off method, FVM and DOM is developed. The enclosure consists of several horizontal, vertical and oblique walls, and thermal conductivity within the enclosure varies directly with temperature and indirectly with position. To simplify the complex geometry, a promising mathematical model is introduced using blocked-off method. Emitting, absorbing and non-isotropic scattering gray are assumed as the main radiative characteristics of the steady medium. Findings DOM and FVM are, respectively, applied for solving radiative transfer equation (RTE) and the energy equation, which includes conduction, radiation and heat source terms. The temperature and heat flux distributions are calculated inside the enclosure. For validation, results are compared with previous data reported in the literature under the same conditions. Results and comparisons show that this approach is highly efficient and reliable for complex geometries with coupled conduction-radiation heat transfer. Finally, the effects of thermo-radiative parameters including surface emissivity, extinction coefficient, scattering albedo, asymmetry factor and conduction-radiation parameter on temperature and heat flux distributions are studied. Originality/value In this paper, a hybrid numerical method is used to analyze coupled conduction-radiation heat transfer in an irregular geometry. Varying thermal conductivity is included in this analysis. By applying the method, results obtained for temperature and heat flux distributions are presented and also validated by the data provided by several previous papers.

scholarly journals Numerical Solution of MHD Viscoelastic Nanofluid Flow over a Stretching Sheet with Partial Slip and Heat Source/Sink

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Mania Goyal ◽  
Rama Bhargava
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Brownian Motion ◽  
Differential Equations ◽  
Heat Source ◽  
Uniform Magnetic Field ◽  
Stretching Sheet ◽  
Partial Slip ◽  
Local Similarity ◽  
Source Sink

We analyze the effect of velocity slip boundary condition on the flow and heat transfer of non-Newtonian nanofluid over a stretching sheet with a heat source/sink, under the action of a uniform magnetic field, orientated normally to the plate. The Brownian motion and thermophoresis effects are also considered. The boundary layer equations governed by the partial differential equations are transformed into a set of ordinary differential equations with the help of local similarity transformations. The differential equations are solved by the variational finite element method (FEM). We have examined the effects of different controlling parameters, namely, the Brownian motion parameter, the thermophoresis parameter, uniform magnetic field, viscoelastic parameter, Prandtl number, heat source/sink parameter, Lewis number, and the slip parameter on the flow field and heat transfer characteristics. Graphical display of the numerical examination is performed to illustrate the influence of various flow parameters on the velocity, temperature, concentration, and Nusselt and Sherwood numbers distributions. The present study has many applications in coating and suspensions, cooling of metallic plate, paper production, heat exchangers technology, and materials processing exploiting.

Unsteady heat and mass transfer magnetohydrodynamic (MHD) nanofluid flow over a stretching sheet with heat source–sink using quasi-linearization technique

2015 ◽  
Vol 93 (12) ◽  
pp. 1477-1485 ◽  
Author(s):  
R. Ahmad ◽  
Waqar A. Khan
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Differential Equations ◽  
Heat Source ◽  
Stretching Sheet ◽  
Volume Fraction ◽  
Numerical Technique ◽  
Stretching Surface ◽  
Nanofluid Flow ◽  
Source Sink

The current study deals with two-dimensional unsteady incompressible MHD water-based nanofluid flow over a convectively heated stretching sheet by considering Buongiorno’s model. A uniform magnetic field is applied in the direction normal to the stretching sheet. It is assumed that the lower surface of the sheet is heated by convection by a nanofluid at temperature Tf, which generates the heat transfer coefficient, hf. Uniform temperature and nanofluid volume fraction are assumed at the sheet’s surface and the flux of the nanoparticle is taken to be zero. The assumption of zero nanoparticle flux at the sheet’s surface makes the model physically more realistic. The effects of the uniform heat source–sink are included in the energy equation. With the help of similarity transformations, the partial differential equations of momentum, energy, and nanoparticle concentration are reduced to a system of nonlinear ordinary differential equations along with the transformed boundary conditions. The derived equations are solved with the help of the quasi-qinearization technique. The model is solved by considering the realistic values for the Lewis number, thermophoresis, and Brownian motion parameters. The objective of the current study is (i) to provide an efficient numerical technique for solving the boundary layer flow model and (ii) introduction of zero nanoparticle flux on the convectively heated stretching surface. The current study also focuses on the physical relevance and accurate trends of the boundary layer profiles, which are adequate in the laminar boundary layer theory. The dependence of the nanoparticle volume fraction and other pertinent parameters on the dimensionless velocity, temperature, shear stress, and heat transfer rates over the stretching surface are presented in the form of profiles.

scholarly journals MHD Flow and Heat Transfer of Hybrid Nanofluid over an Exponentially Shrinking Surface with Heat Source/Sink

2021 ◽  
Vol 11 (17) ◽  
pp. 8199
Author(s):  
Mohamad Nizam Othman ◽  
Alias Jedi ◽  
Nor Ashikin Abu Bakar
Keyword(s):  
Heat Transfer ◽  
Differential Equations ◽  
Heat Source ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Mhd Flow ◽  
Hybrid Nanofluid ◽  
Flow And Heat Transfer ◽  
Source Sink ◽  
Shrinking Surface

In nanotechnology research, nanofluid technology contributes many applications to engineering applications and industry, such as power generation, solar collection, heat exchangers for cooling, and many more. However, there are still a few constraints in terms of heat transfer enhancement, although nanofluid properties show the best heat transfer rate compared with conventional fluids. Thus, this study was conducted for the purpose of investigating the behaviors of flow and heat transfer of hybrid nanofluid with carbon nanotubes (CNTs) on a permeable exponentially shrinking surface, as well as investigating the effects of a magnetic field and heat source/sink. This study was conducted by developing a mathematical model, which was the Tiwari–Das model for momentum and energy equations, and then transforming the model’s partial differential equations (PDEs) to ordinary differential equations (ODEs) using a similarity solution. Next, these equations were solved numerically using the MATLAB bvp4c boundary value problem solver. The authors particularly explored these behaviors with a few variations. Based on the results obtained, it was found that dual solutions exist in a specific range of the shrinking case, and that the critical point also exists in a range of −1.5 < < −1 with different parameters. For the heat source/sink effect, the Nusselt number was higher when heat sink case ε < 0, whereas it decreased when the heat source case ε > 0. Therefore, this study deduced that the heat transfer rate of hybrid nanofluid (CNTs/Cu–water) is better than regular nanofluid (CNT–water) and conventional fluid (water). The present study took into consideration the problem of MHD flow and heat transfer analysis of a hybrid nanofluid towards an exponentially shrinking surface with the presence of heat source/sink and thermal radiation effects. The authors show that dual solutions exist within a specific range of values due to the shrinking case. The current work is predicted to have numerous benefits in equivalent real-world systems.

scholarly journals Scaling group analysis on MHD effects on heat transfer near a stagnation point on a linearly stretching sheet with variable viscosity and thermal conductivity, viscous dissipation and heat source/sink

2015 ◽  
Vol 42 (2) ◽  
pp. 111-133 ◽  
Author(s):  
Hunegnaw Dessie ◽  
Kishan Naikoti
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Differential Equations ◽  
Heat Source ◽  
Stagnation Point ◽  
Viscous Dissipation ◽  
Stretching Sheet ◽  
Variable Viscosity ◽  
Physical Parameters ◽  
Source Sink

The effects of variable viscosity and thermal conductivity on MHD heat transfer flow of viscous incompressible electrically conducting fluid near stagnation point flow on non-conducting stretching sheet in presence of uniform transfer magnetic field with heat source/sink and viscous dissipation has been analyzed. The governing partial differential equations are transformed into ordinary differential equations using a special form of Lie group transformations and then solved using Fourth order Runge-Kutta Method. Effects of different physical parameters on the flow and heat transfer characteristics are analyzed. Variations of different parameters on skin fiction coefficient-f??(0) and temperature gradient ???(0) are presented in tabular form.

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