NUMERICAL INVESTIGATION OF TRANSIENT FLOW-MODE TRANSITION OF LAMINAR NATURAL CONVECTION IN AN INCLINED ENCLOSURE

Steady two-dimensional natural convection in rectangular cavities has been investigated numerically. The conservation equations of mass, momentum and energy under the assumption of a Newtonian Boussinesq fluid have been solved using the finite volume technique embedded in the Fluent code for a Newtonian (water) and three non Newtonian carbopol fluids. The highly accurate Quick differential scheme was used for discretization. The computations were performed for one Rayleigh number, based on cavity height, of 105 and a Prandtl number of 10 and 700, 6,000 and 1.2×104 for the Newtonian and the three non-Newtonian fluids respectively. In all of the numerical experiments, the channel is heated from below and cooled from the top with insulated side-walls and the inclination angle is varied. The simulations have been carried out for one aspect ratio of 6. Comparison between the Newtonian and the non-Newtonian cases is conducted based on the behaviour of the average Nusselt number with angle of inclination. Both Newtonian and non-Newtonian fluids exhibit similar behavior with a sudden drop around an angle of 50° associated with flow mode transition from multi-cell to single-cell mode.

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Numerical Investigation of Laminar Natural Convection in a Circular Enclosure with a Rectangle Cylinder

2011 Asia-Pacific Power and Energy Engineering Conference ◽

10.1109/appeec.2011.5748907 ◽

2011 ◽

Cited By ~ 1

Author(s):

Han Wang ◽

Chuang Sun ◽

Xin-Lin Xia ◽

He-ping Tan

Keyword(s):

Natural Convection ◽

Numerical Investigation ◽

Laminar Natural Convection

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Numerical Investigation of Natural Convection in a Square Enclosure with a Baffle Mounted on Vertical Wall

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.813-814.748 ◽

2015 ◽

Vol 813-814 ◽

pp. 748-753 ◽

Cited By ~ 1

Author(s):

N. Nagasubramanian ◽

M.R. Thansekhar ◽

M. Venkatesan ◽

K. Ramanathan

Keyword(s):

Natural Convection ◽

Numerical Investigation ◽

Average Nusselt Number ◽

Vertical Wall ◽

Temperature Fields ◽

Cold Wall ◽

Primary Vortex ◽

Square Enclosure ◽

Flow And Heat Transfer ◽

Laminar Natural Convection

Results from numerical investigation of laminar natural convection inside a differentially heated square enclosure with a thin baffle attached to the cold wall are reported. The effect of the baffles on the flow and temperature fields were analyzed for baffle lengths equal to 20, 35 and 50 percent of the width of the enclosure, attached at three locations for Ra = 104, 105, 106 and Pr = 0.707. The presence of a baffle on the cold right wall affects the strength of the clockwise rotating primary vortex. Reduced flow and heat transfer are observed. Longer the baffle more pronounced the effect on the flow field. Secondary convection cells are seen between the baffle and the bottom wall for certain cases. Reduction in average Nusselt Number is observed on the cold wall with the baffle than the hot wall.

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