Heat Transfer of Natural Convection in a Rectangular Cavity with Vertical Walls of Different Temperatures

1978 ◽  
Vol 44 (378) ◽  
pp. 598-598
Author(s):  
Nobuhiro SEKI ◽  
Shoichiro FUKUSAKO ◽  
Hideo INABA
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Rectangular Cavity ◽  
Different Temperatures ◽  
Vertical Walls

Effect of Surface Radiation on Conjugate Natural Convection in a Square Enclosure with a Tube at Different Locations

2013 ◽  
Vol 281 ◽  
pp. 190-196 ◽  
Author(s):  
Jian Sheng Wang ◽  
Yong Xu
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Heat Transfer Performance ◽  
Convection Heat Transfer ◽  
Surface Radiation ◽  
Square Enclosure ◽  
Conjugate Natural Convection ◽  
Different Temperatures ◽  
Vertical Walls ◽  
Effect Of Surface

The conjugate natural convection heat transfer with and without the interaction of the surface radiation in a square enclosure was carried out by numerical simulation. The vertical walls of the square enclosure were heated with different temperatures, and the others were adiabatic. A circular tube was inserted into the square enclosure. It was observed that varied location of the tube center can lead to different motion and heat transfer intensities. In addition, surface radiation reduces the convective heat transfer in the square enclosure compared to the pure natural convection case and enhances the overall heat transfer performance.

Experimental Investigation of Natural Convection in Partitioned Enclosures

1982 ◽  
Vol 104 (3) ◽  
pp. 527-532 ◽  
Author(s):  
S. M. Bajorek ◽  
J. R. Lloyd
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Convection Heat Transfer ◽  
Core Region ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
The Core ◽  
Different Temperatures ◽  
Vertical Walls ◽  
Good Agreement

Natural convection heat transfer within a two-dimensional, partitioned enclosure of aspect ratio 1 was investigated experimentally using a Mach-Zehnder interferometer. The vertical walls were maintained isothermal at different temperatures, while the horizontal walls and the partitions were insulated. Local and average heat-transfer coefficients were determined for the air and carbon dioxide filled enclosures both with and without partitions for Grashof numbers between 1.7×105 and 3.0×106. Good agreement was found between the results in the present study for the nonpartitioned enclosure and those previously published. The partitions were found to significantly influence the convective heat transfer. Observations of the interferometric fringes indicated that the core region is unsteady, with the unsteadiness occasionally affecting the flow along the vertical isothermal walls, beginning at Grashof numbers as low as 5×105.

Natural Convection in Cubic and Rhomb-Shaped Enclosures

2013 ◽  
Author(s):  
Milorad B. Dzodzo
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Temperature Fields ◽  
Nusselt Numbers ◽  
Different Temperatures ◽  
Vertical Walls ◽  
Laminar Natural Convection ◽  
Velocity And Temperature Fields ◽  
Prandtl Numbers ◽  
Volume Method

Laminar natural convection in cubic and rhomb–shaped enclosures (rhomb angles 59°, 44° and 28.2°) with two opposite vertical walls kept at different temperatures was investigated experimentally and numerically. The enclosures were filled with glycerol and the Rayleigh (Ra) and Prandtl (Pr) numbers ranged from 2,000<Ra<369,000 and 2,680<Pr<7,000. The visualization of the velocity and temperature fields was obtained by using Plexiglass and liquid crystal particles as tracers. The finite volume method based on the finite difference approach was applied for numerical analysis. The velocity and temperature fields and average Nusselt numbers were found as a function of the Reyleigh and Prandtl numbers. Comparison of the average Nusselt numbers for cubic and rhomb-shaped enclosures indicates decrease of heat transfer for the cases when the lower and upper vertical walls of the rhomb-shaped enclosures are at lower and higher temperatures, respectively. This is due to the tendency of fluid stratification in the lower and upper corners.

scholarly journals Natural Convection in Undivided and Partially Divided Rectangular Enclosures

1981 ◽  
Vol 103 (4) ◽  
pp. 623-629 ◽  
Author(s):  
M. W. Nansteel ◽  
R. Greif
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Temperature Fields ◽  
Transitional Flow ◽  
Two Dimensional ◽  
Injection Flow ◽  
Stabilizing Effect ◽  
Different Temperatures ◽  
Vertical Walls ◽  
Rayleigh Numbers

Heat transfer by natural convection in a two-dimensional rectangular enclosure fitted with partial vertical divisions is investigated experimentally. The horizontal walls of the enclosure are adiabatic while the vertical walls are maintained at different temperatures. The experiments are carried out with water, Pr ≃ 3.5, for Rayleigh numbers in the range, 2.3 × 1010 ⩽ RaL ⩽ 1.1 × 1011, and an aspect ratio, A = H/L = 1/2. The effect of the partial vertical divisions on the fluid flow and temperature fields is investigated by dye-injection flow visualization and by thermocouple probes, respectively. The effect of the partitions on the heat transfer across the enclosure is also studied and correlations for the Nusselt number as a function of RaL and partition length are generated for both conducting and non-conducting partition materials. Partial divisions are found to have a significant effect on the heat transfer; especially when the divisions are adiabatic. The results also indicate that the partial divisions may have a stabilizing effect on the laminar-transitional flow on the heated vertical walls of the enclosure.

Influence of Partition Length on Natural Convection in Partially Divided Square Enclosure

2007 ◽  
Vol 129 (11) ◽  
pp. 1592-1599 ◽  
Author(s):  
C. D. Sankhavara ◽  
H. J. Shukla
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Natural Convection ◽  
Rayleigh Number ◽  
Average Nusselt Number ◽  
Square Enclosure ◽  
Thermal Boundary Conditions ◽  
Different Temperatures ◽  
Vertical Walls ◽  
Good Agreement

Numerical investigation is carried out for natural convection in square enclosures consisting of partitions protruding from the end walls with different thermal boundary conditions at the end walls and partitions. The vertical walls were maintained isothermal at different temperatures. The Rayleigh number varies from 104 to 106 and the Prandtl number is 0.71. The thickness of the partition is fixed and is equal to one-tenth of the width of the enclosure. Their nondimensional length (l∕H) varies from 0 (a nonpartitioned enclosure) to 0.5 (two separate enclosures). A good agreement was found between the results in the present study and those published previously. The partitions were found to significantly influence the convective heat transfer. The average Nusselt number is less in the presence of partitions, and it decreases with increasing partition length (l∕H) from 0 to 0.5.

Natural convection in a rectangular cavity with piece-wise heated vertical walls: multiple states, stability and bifurcations

2002 ◽  
Author(s):  
Vladimir Erenburg ◽  
Alexander Gelfgat ◽  
Eliezer Kit ◽  
Pinhas Z. Bar-Yoseph ◽  
Alexander Solan
Keyword(s):  
Natural Convection ◽  
Rectangular Cavity ◽  
Vertical Walls ◽  
Stability And Bifurcations

Effect of a Magnetic Field on the Heat Transfer Rate on Free Convection in a Rectangular Cavity

2005 ◽  
Author(s):  
Gustavo Gutierrez ◽  
Ezequiel Medici
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Natural Convection ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Stokes Equations ◽  
Rectangular Cavity ◽  
Convection Flow ◽  
Interesting Phenomenon ◽  
The Magnetic Field

The interaction between magnetic fields and convection is an interesting phenomenon because of its many important engineering applications. Due to natural convection motion the electric conductive fluid in a magnetic field experiences a Lorenz force and its effect is usually to reduce the flow velocities. A magnetic field can be used to control the flow field and increase or reduce the heat transfer rate. In this paper, the effect of a magnetic field in a natural convection flow of an electrically conducting fluid in a rectangular cavity is studied numerically. The two side walls of the cavity are maintained at two different constant temperatures while the upper wall and the lower wall are completely insulated. The coupling of the Navier-Stokes equations with the Maxwell equations is discussed with the assumptions and main simplifications assumed in typical problems of magnetohydrodynamics. The nonlinear Lorenz force generates a rich variety of flow patterns depending on the values of the Grashof and Hartmann numbers. Numerical simulations are carried out for different Grashof and Hartmann numbers. The effect of the magnetic field on the Nusselt number is discussed as well as how convection can be suppressed for certain values of the Hartmann number under appropriate direction of the magnetic field.

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