scholarly journals Natural convection flow in a square cavity with internal heat generation and a flush mounted heater on a side wall

2011 ◽  
Vol 7 (2) ◽  
pp. 37-50 ◽  
Author(s):  
Md. Mustafizur Rahman ◽  
M. Arif Hasan Mamun ◽  
M. Masum Billah ◽  
Saidur Rahman
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Natural Convection ◽  
Heat Generation ◽  
Vertical Wall ◽  
Heated Wall ◽  
Convection Flow ◽  
Square Cavity ◽  
Natural Convection Flow ◽  
Heater Length

In this study natural convection flow in a square cavity with heat generating fluid and a finite size heater on the vertical wall have been investigated numerically. To change the heat transfer in the cavity, a heater is placed at different locations on the right vertical wall of the cavity, while the left wall is considered to be cold. In addition, the top and bottom horizontal walls are considered to be adiabatic and the cavity is assumed to be filled with a Bousinessq fluid having a Prandtl number of 0.72. The governing mass, momentum and energy equations along with boundary conditions are expressed in a normalized primitive variables formulation. Finite Element Method is used in solution of the normalized governing equations. The parameters leading the problem are the Rayleigh number, location of the heater, length of the heater and heat generation. To observe the effects of the mentioned parameters on natural convection in the cavity, we considered various values of heater locations, heater length and heat generation parameter for different values of Ra varying in the range 102 to 105. Results are presented in terms of streamlines, isotherms, average Nusselt number at the hot wall and average fluid temperature in the cavity for the mentioned parameters. The results showed that the flow and thermal fields through streamlines and isotherms as well as the rate of heat transfer from the heated wall in terms of Nusselt number are strongly dependent on the length and locations of the heater as well as heat generating parameter.DOI: 10.3329/jname.v7i2.3292 

Numerical Simulation of Natural Convection Flow in a Cube With a Horizontal Heated Strip

2008 ◽  
Author(s):  
Esam M. Alawadhi
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Nusselt Number ◽  
High Temperature ◽  
Natural Convection ◽  
Vertical Wall ◽  
Convection Flow ◽  
Front Wall ◽  
Natural Convection Flow ◽  
Rayleigh Numbers

Natural convection flow in a cube with a heated strip is solved numerically. The heated strip is attached horizontally to the front wall and maintained at high temperature, while the entire opposite wall is maintained at low temperature. The heated strip simulates an array of electronic chips The Rayleigh numbers of 104, 105, and 106 are considered in the analysis and the heated strip is horizontally attached to the wall. The results indicate that the heat transfer strongly depends on the position of the heated strip. The maximum Nusselt number can be achieved if the heater is placed at the lower half of the vertical wall. Increasing the Rayleigh number significantly promotes heat transfer in the enclosure. Flow streamlines and temperature contours are presented, and the results are validated against published works.

Aspect Ratio Effect on Natural Convection Flow in a Cavity Submitted to a Periodical Temperature Boundary

2006 ◽  
Vol 129 (8) ◽  
pp. 1060-1068 ◽  
Author(s):  
Nader Ben Cheikh ◽  
Brahim Ben Beya ◽  
Taieb Lili
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Aspect Ratio ◽  
Vertical Wall ◽  
Heated Wall ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Temperature Boundary ◽  
Shallow Cavities ◽  
Periodic Temperature

The effect of aspect ratio on natural convection flow in a cavity submitted to periodic temperature boundary, is investigated numerically. The temperature of the heated wall is either maintained constant or varied sinusoidally with time while the temperature of the opposite vertical wall is maintained constant. The results are given for a range of varied parameters as Rayleigh number (5×103⩽Ra⩽106), cavity aspect ratio (1∕6⩽A⩽8), and period of the sinusoidally heated wall (1⩽τ⩽1600). The amplitude of oscillation (a=0.8) and the Prandtl number (Pr=0.71) were kept constant. The results obtained in the steady state regime show that the heat transfer averaged over the cold wall is maximum when the aspect ratio is in the range 1⩽A⩽2. In the case of a periodic temperature boundary, it is shown that the deviation between the mean heat transfer and the heat transfer of the constant heated case is larger for shallow cavities.

scholarly journals Numerical Investigation of Natural Convection Flow in a Hexagonal Enclosure Having Vertical Fin

2019 ◽  
Vol 11 (2) ◽  
pp. 173-183 ◽  
Author(s):  
M. Fayz -Al- Asad ◽  
M. M. A. Sarker ◽  
M. J. H. Munshi
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Natural Convection ◽  
Transfer Rate ◽  
Numerical Study ◽  
Bottom Wall ◽  
Convection Flow ◽  
Temperature Profiles ◽  
Natural Convection Flow ◽  
Fin Efficiency

Numerical study of natural convection flow in a hexagonal enclosure with a single vertical fin attached to its heated bottom wall has been carried out. Finite element method based Galerkin weighted residual technique is used to solve the governing equation. The horizontal walls of the enclosure are kept at constant high temperature while the inclined walls are kept at constant cold temperature. A vertical heated fin is attached to the hot bottom wall with a length  at a position  from the left surface having thickness . The Prandlt number for the flow inside the enclosure is 0.71. The results of the problem are presented in graphical and tabular forms and discussed. The fin efficiency and temperature distribution were examined. The numerical results indicate the strong influence of the mentioned parameters on the flow structure and heat transfer as well as temperature. A set of graphical results are presented in terms of streamlines, isotherms contour, temperature profiles, velocity profiles, local Nusselt number and average Nusselt number. The obtained results indicated that the heat transfer rate increases with the increase of Rayleigh number in a hexagonal enclosure. The results are validated comparing with the published works.

scholarly journals MHD NATURAL CONVECTION FLOW ALONG A VERTICAL WAVY SURFACE IN PRESENCE OF HEAT GENERATION/ABSORPTION WITH VISCOSITY DEPENDENT ON TEMPERATURE

2013 ◽  
Vol 42 (1) ◽  
pp. 47-55
Author(s):  
N. Parveen ◽  
M. A. Alim
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Heat Generation ◽  
Variable Viscosity ◽  
Wavy Surface ◽  
Convection Flow ◽  
Heat Transfer Characteristics ◽  
Natural Convection Flow ◽  
Box Scheme ◽  
Vertical Flat Plate

The present numerical simulation is analyzed the Magnetohydrodynamic natural convection flow andheat transfer along a uniformly heated vertical wavy surface in presence of heat generation/absorption withtemperature dependent variable viscosity. Using the appropriate transformations the governing boundary layerequations are reduced to non-dimensional forms. The resulting nonlinear system of partial differentialequations are mapped into the domain of a vertical flat plate and then solved numerically applying implicitfinite difference method together with Keller-box scheme. The solutions are expressed in terms of the skinfriction coefficient, the rate of heat transfer, the streamlines as well as the isotherms over the whole boundarylayer. The implications of heat generation/absorption parameter (Q) and viscosity parameter (?) on the flowstructure and heat transfer characteristics are investigated in detail while, Prandtl number (Pr), magneticparameter (M) and the amplitude-to-length ratio of the wavy surface (?) are considered fixed. Comparison withpreviously published work is performed and is found to be in good agreement.DOI: http://dx.doi.org/10.3329/jme.v42i1.15944

Unsteady MHD natural convection flow of a nanofluid inside an inclined square cavity containing a heated circular obstacle

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
M. A. Mansour ◽  
Rama Subba Reddy Gorla ◽  
Sadia Siddiqa ◽  
A. M. Rashad ◽  
T. Salah
Keyword(s):  
Nusselt Number ◽  
Natural Convection ◽  
Average Nusselt Number ◽  
Convection Flow ◽  
Square Cavity ◽  
Natural Convection Flow ◽  
Symmetric Pattern ◽  
Inclined Cavity ◽  
The Right ◽  
Good Agreement

Abstract The phenomena of unsteady magnetohydrodynamics (MHD) natural convection flow in an inclined square cavity filled with nanofluid and containing a heated circular obstacle at its center with heat generation/absorption impact are examined numerically. The cavity’s right and left walls are maintained at low temperatures, while the remaining walls are adiabatic. The volumetric external force, MHD, is applied across the inclined cavity. A penalty formulation-based finite element method is used to solve the nonlinear set of governing equations iteratively. The numerical scheme and results are validated through a comparison with the benchmark results, and it shows that our solutions are in good agreement with them. The results are shown in terms of contours of streamlines, isotherms, and average Nusselt number. It is observed that MHD alters the streamlines, isotherms, and average Nusselt number and dominates the flow as compared to any other physical parameter. The average Nusselt number is found sensitive to the central obstacle’s size, and it reduces sufficiently when the radius of the inner cylinder increases. For all the parameters, the streamlines’ symmetric pattern holds, such that the anti-clockwise cells on the left side of the cavity have their symmetric clockwise cells on the right side.

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