Cooling of a Vertical Shrouded Fin Array by Natural Convection: A Numerical Study

1987 ◽  
Vol 109 (3) ◽  
pp. 671-676 ◽  
Author(s):  
K. C. Karki ◽  
S. V. Patankar
Keyword(s):  
Natural Convection ◽  
Numerical Study ◽  
Bulk Temperature ◽  
Heat Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Developing Flow ◽  
Laminar Natural Convection ◽  
System Geometry ◽  
Chimney Effect ◽  
Axial Development

An analysis is made of the laminar natural convection in a vertical shrouded fin array, in which the flow is induced from the surroundings by the chimney effect. This involves the calculation of developing flow in a duct. The results are obtained numerically for representative values of the parameters describing the system geometry and ducts of different lengths. The axial development of various flow quantities, such as the Nusselt number and the bulk temperature, has been presented. In addition, the overall flow and heat transfer characteristics have been discussed.

Natural convection in a rectangular cavity filled with nanofluids

2018 ◽  
Vol 28 (6) ◽  
pp. 1410-1432 ◽  
Author(s):  
Cornelia Revnic ◽  
Eiyad Abu-Nada ◽  
Teodor Grosan ◽  
Ioan Pop
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Design Methodology ◽  
Volume Fraction ◽  
Numerical Study ◽  
Rectangular Cavity ◽  
Heat Transfer Characteristics ◽  
Content Type ◽  
Flow And Heat Transfer ◽  
Comprehensive Survey

Purpose This paper aims to develop a numerical study of the steady natural convection in a rectangular cavity filled with the CuO–water-based nanofluid. It is assumed that the viscosity of nanofluids depends on the temperature and on the nanofluids volume fraction. Design/methodology/approach The mathematical nanofluid model has been formulated on the basis of the model proposed by Buongiorno (2006). The system of partial differential equations is written in terms of a dimensionless stream function, vorticity, temperature and the volume fraction of the nanoparticles, and is solved numerically using the finite difference method for different values of the governing parameters. Findings It is found that both fluid flow and heat transfer coefficient are affected by the considered parameters. Thus, the Nusselt number is slowly increasing with increasing volume fraction from 2 per cent to 5 per cent and it is more pronounced increasing with increasing Rayleigh number from 103 to 105. Originality/value Buongiorno’s (2006) nanofluid model has been applied for the flow with the characteristics as mentioned in the paper. A comprehensive survey on the behavior of flow and heat transfer characteristics has been presented. All plots presented in the paper are new and are not reported in any other study.

Combined Forced and Free Laminar Convection in the Entrance Region of an Inclined Isothermal Tube

1988 ◽  
Vol 110 (4a) ◽  
pp. 901-909 ◽  
Author(s):  
D. Choudhury ◽  
S. V. Patankar
Keyword(s):  
Numerical Results ◽  
Entrance Region ◽  
Heat Transfer Characteristics ◽  
Local Pressure ◽  
Flow And Heat Transfer ◽  
Developing Flow ◽  
Free And Forced Convection ◽  
Laminar Convection ◽  
Independent Parameters ◽  
Axial Development

An analysis is made of the combined forced and free convection for laminar flow in the entrance region of isothermal, inclined tubes. This involves the numerical calculation of the developing flow with significant buoyancy effects. Three independent parameters are introduced: the Prandtl number Pr, a modified Rayleigh number Ra*, and Ω, a parameter that measures the relative importance of free and forced convection. The inclination angle does not appear explicitly in the formulation. Numerical results are obtained for Pr = 0.7, 5, and 10, and representative values of Ra* and Ω. The axial development of the velocity profiles, temperature field, local pressure gradient, and the Nusselt number are presented. These results reveal that the buoyancy effects have a considerable influence on the fluid flow and heat transfer characteristics of the development flow. A comparison of the numerical results with the available experimental data is also presented.

scholarly journals Numerical Study of Laminar Natural Convection in an Arch Enclosure Filled with Al2O3-Water Based Nanofluid

2016 ◽  
Vol 9 (6) ◽  
pp. 1927-1936 ◽  
Author(s):  
Manoj Kumar Triveni ◽  
Dipak Sen ◽  
Rajsekhar Panua ◽  
◽  
◽  
...  
Keyword(s):  
Natural Convection ◽  
Numerical Study ◽  
Water Based ◽  
Laminar Natural Convection

Three Dimensional Numerical Simulation of the Natural Convection in an Annulus With an Internal Slotted Cylinder

2011 ◽  
Author(s):  
Mo Yang ◽  
Jin Wang ◽  
Kun Zhang ◽  
Ling Li ◽  
Yuwen Zhang
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Convection Heat Transfer ◽  
Natural Convection Heat Transfer ◽  
Dimensional Model ◽  
Heat Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Rayleigh Numbers

Detailed numerical analysis is presented for three-dimensional natural convection heat transfer in annulus with an internal concentric slotted cylinder. The internal slotted cylinder and the outer annulus are maintained at uniform but different temperatures. Governing equations are discretized using control volume technique based on staggered grid formulation and solved using SIMPLE algorithm with QUICK scheme. Flow and heat transfer characteristics are investigated for a Rayleigh number range of 10 to 106 while Prandtl number (Pr) is taken to be 0.7. The results indicate, at Rayleigh numbers below 105, the system shows two dimensional flow and heat transfer characteristics. On the other hand, the flow and heat transfer shows three dimensional characteristics while for Rayleigh numbers greater than 5×105. Comparison with experimental results indicated that the numerical solutions by three dimensional model can obtain more accuracy than the numerical solutions by two dimensional model. Besides, Numerical results show that the average equivalent conductivity coefficient of natural convection heat transfer of this problem can be enhanced by as much as 30% while relative slot width is more than 0.1.

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