Theoretical study of two-dimensional laminar natural convection about an inclined isothermal corrugated surface

1979 ◽  
Vol 100 (1-2) ◽  
pp. 657-671 ◽  
Author(s):  
Halim Abdurrachim ◽  
Michel Daguenet
Keyword(s):  
Natural Convection ◽  
Theoretical Study ◽  
Two Dimensional ◽  
Corrugated Surface ◽  
Laminar Natural Convection

Laminar Natural Convection in a Discretely Heated Cavity: I—Assessment of Three-Dimensional Effects

1995 ◽  
Vol 117 (4) ◽  
pp. 902-909 ◽  
Author(s):  
T. J. Heindel ◽  
S. Ramadhyani ◽  
F. P. Incropera
Keyword(s):  
Natural Convection ◽  
Vertical Wall ◽  
Three Dimensional ◽  
Companion Paper ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Nusselt Numbers ◽  
Aspect Ratios ◽  
Laminar Natural Convection

Two and three-dimensional calculations have been performed for laminar natural convection induced by a 3 × 3 array of discrete heat sources flush-mounted to one vertical wall of a rectangular cavity whose opposite wall was isothermally cooled. Edge effects predicted by the three-dimensional model yielded local and average Nusselt numbers that exceeded those obtained from the two-dimensional model, as well as average surface temperatures that were smaller than the two-dimensional predictions. For heater aspect ratios Ahtr ≲ 3, average Nusselt numbers increased with decreasing Ahtr. However, for Ahtr ≳ 3, the two and three-dimensional predictions were within 5 percent of each other and results were approximately independent of Ahtr. In a companion paper (Heindel et al., 1995a), predictions are compared with experimental results and heat transfer correlations are developed.

Natural Convection in Two-Dimensional Horizontal Channel With Heat Sources

2003 ◽  
Author(s):  
Tito Dias ◽  
Luiz Fernando Milanez
Keyword(s):  
Natural Convection ◽  
Flux Ratio ◽  
Horizontal Channel ◽  
Maximum Temperature ◽  
Computational Domain ◽  
Heat Sources ◽  
Two Dimensional ◽  
Temperature Excess ◽  
Fluid Properties ◽  
Laminar Natural Convection

Laminar natural convection in a two-dimensional horizontal channel is very important in laptop design, since optimizing the utilization of the cooler saves energy from the battery. In this work, this configuration has been numerically studied. Three cases were studied according to the position of the heat sources in the lower wall, upper wall and both. The computational domain consisted of two adiabatic walls where the heat sources were positioned, and two open boundaries, where the manometric pressure and normal gradient of velocity were zero. Ambient temperature was prescribed for the entering fluid and zero normal gradient for the exiting fluid. Fluid properties were assumed constant except for the density change with temperature on the buoyancy term. The influence of the modified Rayleigh number, position of the heat sources and heat flux ratio between the sources were analyzed for Prandtl number of 0.7. The maximum temperature excess on the heat source is lower for the case with two heat sources and Ra = 104. This preliminary study showed the existence of a minimum value of the excess temperature for the studies aspect ratio (0.1).

Heat Transfer by Laminar Natural Convection Within Rectangular Enclosures

1970 ◽  
Vol 92 (1) ◽  
pp. 159-167 ◽  
Author(s):  
M. E. Newell ◽  
F. W. Schmidt
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Three Dimensional ◽  
Time Dependent ◽  
Two Dimensional ◽  
Numerical Techniques ◽  
Grashof Number ◽  
Different Temperatures ◽  
Laminar Natural Convection ◽  
Steady State Solutions

Two-dimensional laminar natural convection in air contained in a long horizontal rectangular enclosure with isothermal walls at different temperatures has been investigated using numerical techniques. The time-dependent governing differential equations were solved using a method based on that of Crank and Nicholson. Steady-state solutions were obtained for height to width ratios of 1, 2.5, 10, and 20, and for values of the Grashof number, GrL′, covering the range 4 × 103 to 1.4 × 105. The bounds on the Grashof number for H/L = 20 is 8 × 103 ≤ GrL′ ≤ 4 × 104. The results were correlated with a three-dimensional power law which, yielded H/L=1Nu¯L′=0.0547(GrL′)0.3972.5≤H/L≤20Nu¯L′=0.155(GrL′)0.315(H/L)−0.265 The results compare favorably with available experimental results.

scholarly journals Steady laminar natural convection of nanofluid under the impact of magnetic field on two-dimensional cavity with radiation

AIP Advances ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 065008 ◽  
Author(s):  
S. Saleem ◽  
Trung Nguyen-Thoi ◽  
Ahmad Shafee ◽  
Zhixiong Li ◽  
Ebenezer Bonyah ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Natural Convection ◽  
Two Dimensional ◽  
Laminar Natural Convection ◽  
The Impact ◽  
Steady Laminar

scholarly journals Laminar natural convection of non-Newtonian power-law fluid in an eccentric annulus

2019 ◽  
pp. 424-424
Author(s):  
Oussama Benhizia ◽  
Mohamed Bouzit ◽  
Ahmed Dellil
Keyword(s):  
Nusselt Number ◽  
Natural Convection ◽  
Power Law ◽  
Average Nusselt Number ◽  
Two Dimensional ◽  
Power Law Fluid ◽  
Eccentric Annulus ◽  
Nusselt Numbers ◽  
Laminar Natural Convection ◽  
Good Agreement

This work is about studying the natural convection of two-dimensional steady state non-Newtonian power law fluid numerically. The inner cylinder was put eccentrically into the outer one. The cylinders are held at constant temperatures with the inner one heated isothermally at temperature Th and the outer one cooled isothermally at temperature Tc (Th>Tc). The simulations have been taken for the parameters 103?Ra?105, 10?Pr?103, 0.6?n?1.4, 0???0.9 and an inclination angle ? from 0? up to 90?. The average Nusselt numbers for the previous parameters are obtained and discussed numerically. The results revealed that the average Nusselt number has the highest values when n=0.6, Ra=105 at ?=0 which is a signal for the large transfer herein and has the lowest values for n=1.4, Ra=103 at ?=90? which is a signal that the transfer is by conduction more than convection. Furthermore, the increasing of eccentricity causes an increase in the Nusselt number for all the cases. Finally, the best case where we can get the best heat transfer is at ? = 0, ?=0.9 among them all. The results have compared with some precedent works and showed good agreement.

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