scholarly journals Numerical investigation on natural convection of nanofluids in an inclined square enclosure with non-uniform heated walls

2018 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
Xiaofeng Wang ◽  
Weizhong Dai
Keyword(s):  
Natural Convection ◽  
Numerical Investigation ◽  
Square Enclosure

Experimental and Numerical Investigation on Natural Convection Heat Transfer of TiO2–Water Nanofluids in a Square Enclosure

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Yanwei Hu ◽  
Yurong He ◽  
Shufu Wang ◽  
Qizhi Wang ◽  
H. Inaki Schlaberg
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Natural Convection ◽  
Numerical Investigation ◽  
Convection Heat Transfer ◽  
Distribution Functions ◽  
Lattice Boltzmann Model ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Square Enclosure

An experimental and numerical investigation on natural convection heat transfer of TiO2–water nanofluids in a square enclosure was carried out for the present work. TiO2–water nanofluids with different nanoparticle mass fractions were prepared for the experiment and physical properties of the nanofluids including thermal conductivity and viscosity were measured. Results show that both thermal conductivity and viscosity increase when increasing the mass fraction of TiO2 nanoparticles. In addition, the thermal conductivity of nanofluids increases, while the viscosity of nanofluids decreases with increasing the temperature. Nusselt numbers under different Rayleigh numbers were obtained from experimental data. Experimental results show that natural convection heat transfer of nanofluids is no better than water and even worse when the Rayleigh number is low. Numerical studies are carried out by a Lattice Boltzmann model (LBM) coupling the density and the temperature distribution functions to simulate the convection heat transfer in the enclosure. The experimental and numerical results are compared with each other finding a good match in this investigation, and the results indicate that natural convection heat transfer of TiO2–water nanofluids is more sensitive to viscosity than to thermal conductivity.

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

2015 ◽  
Vol 813-814 ◽  
pp. 748-753 ◽  
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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