Numerical Study of Combined Radiation and Turbulent Mixed Convection Heat Transfer in a Compartment Containing Participating Media

2015 ◽  
Vol 31 (4) ◽  
pp. 467-480 ◽  
Author(s):  
A. Asghari ◽  
S. A. Gandjalikhan Nassab ◽  
A. B. Ansari
Keyword(s):  
Mixed Convection ◽  
Stokes Equations ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Convection Heat Transfer ◽  
Simple Algorithm ◽  
Convection Flow ◽  
Algebraic Equations ◽  
Mixed Convection Flow ◽  
Participating Media

AbstractThe effect of radiation on turbulent mixed convection flow, generated by two plane wall jets with different temperatures inside a cavity was studied numerically. The medium is treated as a gray, absorbing, emitting and scattering. The two-dimensional Reynolds-average Navier-Stokes equations, coupled with the energy equation are solved by using the computational fluid dynamic (CFD) techniques, while the AKN low-Reynolds-number model is employed for computation of turbulence fluctuations. The Boussinesq approximation is used to calculate the buoyancy term, and the radiation part of the problem is solved by numerical solution of the radiative transfer equation (RTE) with the well known discrete ordinate method (DOM). The governing equations are discretized by the finite volume technique into algebraic equations and solved with the SIMPLE algorithm. The effects of radiation conduction parameter, scattering albedo, optical thickness and Richardson number on the thermal behavior of the system are carried out. Results show that the gas radiation has a significant effect on the temperature distribution inside the turbulent mixed convection flow.

A new approximate analytical technique for dual solutions of nonlinear differential equations arising in mixed convection heat transfer in a porous medium

2017 ◽  
Vol 27 (2) ◽  
pp. 486-503 ◽  
Author(s):  
S. Abbasbandy ◽  
Elyas Shivanian ◽  
K. Vajravelu ◽  
Sunil Kumar
Keyword(s):  
Differential Equations ◽  
Mixed Convection ◽  
Nonlinear Differential Equations ◽  
Convection Heat Transfer ◽  
Dual Solutions ◽  
Convection Flow ◽  
Mixed Convection Flow ◽  
Infinite Domain ◽  
Content Type ◽  
Mixed Convection Heat Transfer

Purpose The purpose of this paper is to present a new approximate analytical procedure to obtain dual solutions of nonlinear differential equations arising in mixed convection flow in a semi-infinite domain. This method, which is based on Padé-approximation and homotopy–Padé technique, is applied to a model of magnetohydrodynamic Falkner–Skan flow as well. These examples indicate that the method can be successfully applied to solve nonlinear differential equations arising in science and engineering. Design/methodology/approach Homotopy–Padé method. Findings The main focus of the paper is on the prediction of the multiplicity of the solutions, however we have calculated multiple (dual) solutions of the model problem namely, mixed convection heat transfer in a porous medium. Research limitations/implications The authors conjecture here that the combination of traditional–Pade and Hankel–Pade generates a useful procedure to predict multiple solutions and to calculate prescribed parameter with acceptable accuracy as well. Validation of this conjecture for other further examples is a challenging research opportunity. Social implications Dual solutions of nonlinear differential equations arising in mixed convection flow in a semi-infinite domain. Originality/value In this study, the authors are using two modified methods.

scholarly journals Entropy generation due to the mixed convection flow of MWCNT−MgO/water hybrid nanofluid in a vented complex shape cavity

2020 ◽  
Vol 307 ◽  
pp. 01007
Author(s):  
Mahdi Benzema ◽  
Youb Khaled Benkahla ◽  
Ahlem Boudiaf ◽  
Seif-Eddine Ouyahia ◽  
Mohammed El Ganaoui
Keyword(s):  
Mixed Convection ◽  
Entropy Generation ◽  
Complex Shape ◽  
Volume Fraction ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Convection Flow ◽  
Hybrid Nanofluid ◽  
Bejan Number ◽  
Inclined Plate

This paper reports a numerical study of mixed convection heat transfer with entropy generation in a vented complex shape cavity filled with MWCNT−MgO (15:85 vol %) /water hybrid nanofluid. A hot source is placed at the mid potion of the inclined plate of the enclosure, while the rest of the rigid walls are adiabatic. A thermo-dependent correlations proposed by [12] for the dynamic viscosity and the thermal conductivity, especially developed for the considered fluid, are used. After validation of the model, the analysis has been done for a Reynolds numbers ranging from 10 to 600 and total nanoparticles volume fraction ranging from 0.0 to 0.02 using the finite volume method. The predicted results of streamlines, isotherms, isentropic lines, average Nusselt number, average entropy generation and average Bejan number are the main focus of interest in the present paper.

scholarly journals Numerical study of magneto-hydrodynamic (MHD) mixed convection flow in a lid-driven triangular cavity

2015 ◽  
Vol 12 (1) ◽  
pp. 21-32
Author(s):  
Mohammed Nasir Uddin ◽  
Aki Farhana ◽  
Md. Abdul Alim
Keyword(s):  
Rayleigh Number ◽  
Prandtl Number ◽  
Mixed Convection ◽  
Hartmann Number ◽  
Numerical Study ◽  
Bulk Temperature ◽  
Convection Flow ◽  
Mixed Convection Flow ◽  
Coupled Equations ◽  
Wide Range

In the present paper, the effect of magneto-hydrodynamic (MHD) on mixed convection flow within a lid-driven triangular cavity has been numerically investigated. The bottom wall of the cavity is considered as heated. Besides, the left and the inclined wall of the triangular cavity are assumed to be cool and adiabatic. The cooled wall of the cavity is moving up in the vertical direction. The developed mathematical model is governed by the coupled equations of continuity, momentum and energy to determine the fluid flow and heat transfer characteristics in the cavity as a function of Rayleigh number, Hartmann number and the cavity aspect ratio. The present numerical procedure adopted in this investigation yields consistent performance over a wide range of parameters Rayleigh number Ra (103-104), Prandtl number Pr (0.7 - 3) and Hartmann number Ha (5 - 50). The numerical results are presented in terms of stream functions, temperature profile and Nussult numbers. It is found that the streamlines, isotherms, average Nusselt number, average fluid bulk temperature and dimensionless temperature in the cavity strongly depend on the Rayleigh number, Hartmann number and Prandtl number.

Numerical Study of Mixed Convection Flow in an Impinging Jet CVD Reactor for Atmospheric Pressure Deposition of Thin Films

2004 ◽  
Vol 126 (5) ◽  
pp. 764-775 ◽  
Author(s):  
S. P. Vanka ◽  
Gang Luo ◽  
Nick G. Glumac
Keyword(s):  
Thin Films ◽  
Mixed Convection ◽  
Atmospheric Pressure ◽  
Flow Reactor ◽  
Numerical Study ◽  
Impinging Jet ◽  
Convection Flow ◽  
Moderate Pressure ◽  
Operating Pressure ◽  
Mixed Convection Flow

A systematic numerical study has been conducted of the mixed convection flow in a novel impinging jet chemical vapor deposition (CVD) reactor for deposition of thin films at atmospheric pressure. The geometry resembles that of a pancake reactor but the inflow gases enter through a small nozzle to provide high inlet momentum. A finite-volume-based computational procedure is used to integrate the governing flow, energy, and scalar transport equations with high accuracy. The effects of the temperature dependent properties are fully accounted for. The effects of operating pressure, wafer rotation rate, and inlet flow rate of the carrier gas are investigated. The main benefit of the new geometry is the suppression of the buoyancy-driven flow even at atmospheric pressures due to the lower mixed convection parameter. We show that the new geometry can produce thin films of high radial uniformity and also with high growth rate. Comparisons are also made with a conventional stagnation flow reactor for which it is shown that beyond a moderate pressure (∼0.1 atm), the flow is dominated by natural convection, and the reactor is unsuitable for practical use.

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