Forced Convection Heat Transfer From a Bank of Circular Cylinders Embedded in a Porous Medium

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Gazy F. Al-Sumaily
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Forced Convection ◽  
Convection Heat Transfer ◽  
Spectral Element ◽  
Circular Cylinders ◽  
Convection Heat ◽  
Forced Convection Heat Transfer ◽  
Spacing Parameter ◽  
Energy Equations

The characteristics of fluid flow and forced convection heat transfer around a bank of four circular cylinders embedded in a metallic or non-metallic porous materials have been investigated numerically. Both a staggered and an in-line arrangement have been studied. The governing continuity, Darcy–Brinkman–Forchheimer momentum, and local thermal non-equilibrium energy equations are solved by the spectral-element method. Attention is focused on how the spacing parameter SP ∈ [1.5, 3.0] (the space between cylinder centers) affects the local and average heat transfer from the cylinders at three different solid-to-fluid thermal conductivity ratios kr = 1.725, 57.5, 248, and at different Reynolds numbers ReD ∈ [1, 250] in both arrangements. Perhaps not surprisingly, the results show that both the average Nusselt number, Nuf, and the local Nusselt number, Nufφ, are dependent strongly on ReD, SP, and the cylinder arrangement. However, it is found that the trend of the variations of Nuf with SP is not considerably altered by kr in both cylinders’ configurations. The results also show that the thermal performance of the staggered arrangement is higher than that for the in-line one, with less occupied space; therefore, it is practically and economically recommended that this arrangement to be used in manufacturing tubular heat exchangers for applications involving porous media.

scholarly journals Numerical study of forced convection heat transfer over three cylinders in staggered arrangement immersed in porous media

2018 ◽  
Vol 22 (1 Part B) ◽  
pp. 467-475 ◽  
Author(s):  
Habib-Olah Sayehvand ◽  
Sakene Yari ◽  
Parsa Basiri
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Forced Convection ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Circular Cylinders ◽  
Convection Heat ◽  
State Equations ◽  
Forced Convection Heat Transfer ◽  
Staggered Arrangement

Staggered arrangement is one of the common configurations in heat exchangers that make better mixing of flow and heat transfer augmentation than other arrangements. In this paper forced convection heat transfer over three isothermal circular cylinders in staggered configuration in isotropic packed bed was investigated. In this work laminar 2-D incompressible steady-state equations of momentum and energy were solved numerically by finite volume method. Simulation was done in three Reynolds numbers of 80, 120, and 200. The results indicate that, using porous medium the Nusselt number enhanced considerably for any of cylinders and it presents thin temperature contours for them. Also is shown that by increasing Reynolds number, the heat transfer increased in both channel but the growth rate of it in porous media is larger. In addition, results of simulation in porous channel show that with increasing Peclet number, heat transfer increased logarithmically.

On the Nusselt Number for H2 Heat Transfer in Rectangular Ducts of Large Aspect Ratios

2014 ◽  
Vol 136 (7) ◽  
Author(s):  
C. Y. Wang
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Aspect Ratio ◽  
Forced Convection ◽  
Parallel Plate ◽  
Convection Heat Transfer ◽  
Analytic Method ◽  
Convection Heat ◽  
Forced Convection Heat Transfer ◽  
Aspect Ratios

The H1 and H2 forced convection heat transfer in rectangular ducts are studied using an accurate, analytic method. It is confirmed that, as the aspect ratio tends to infinity, the Nusselt number for the H2 case approaches 2.9162, much lower than the parallel plate value of 8.2353 attained by the H1 case. The controversy about the H2 limit is thus settled. An explanation of the behavior is suggested.

scholarly journals Investigation Of Forced Convection Heat Transfer From A Heater Mounted Ina Cavity Wall Using Various Nanofluids

2019 ◽  
Vol 128 ◽  
pp. 07002
Author(s):  
R. Kanna ◽  
Sayed Sayeed Ahmad ◽  
P. Venkata Reddy ◽  
Chithirai Pon Selvan ◽  
Tale ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Forced Convection ◽  
Volume Fraction ◽  
Convection Heat Transfer ◽  
Cavity Wall ◽  
Main Stream ◽  
Convection Heat ◽  
Forced Convection Heat Transfer

Forced convection heat transfer from heater mounted in a cavity wall is investigated to reveal the relation among nanofluid properties. The base fluid is considered as water. The present study is focused on forced convection heat transfer from square heater subject to inflow and outflow inside a squarecavity. The interesting physics will be reported in connection with volume fraction, Reynolds number and nanomaterial properties. It is found that for a particular Reynolds number when nanomaterial is introduced the local heat transfer is increased. The wall attached vortex attributes a constant Nusselt number. It is also noticed that when the heater wall is subject to combination of vortex and main stream fluid results high Nusselt number than heat transfer due to wall attached vortices. Nanofluid results high Nusselt number for the same Reynolds number.

Forced Convection Heat Transfer from a Pair of Circular Cylinders Confined in Ventilated Enclosure

2020 ◽  
Vol 26 ◽  
pp. 104-111 ◽  
Author(s):  
Mustapha Helmaoui ◽  
Houssem Laidoudi ◽  
Azzedine Belbachir ◽  
Adel Ayad ◽  
Abedallah Ghaniam
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Forced Convection ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Vertical Wall ◽  
Convection Heat Transfer ◽  
Circular Cylinders ◽  
Convection Heat ◽  
Forced Convection Heat Transfer

This paper deals with a numerical simulation of laminar forced convection heat transfer from a pair of identical circular cylinders placed at the center of square cavity in the line array, the cavity is ventilated with single inlet and outlet ports, the inlet port is located at the middle of left vertical wall and the outlet port is located at the middle of right vertical wall. The work represents the effects of the distance between cylinders and Reynolds number on fluid flow and heat transfer rate. The governing equations of continuity, momentum and energy are solved by using finite-volume method. The obtained results are represented and discussed for following conditions: Reynolds number Re = 1 to 40, Prandtl number Pr = 7.01 and the gap distance S = 0.3L to 0.7L, where L is the cavity length. The main results are potted under the streamline and isotherm contours, the total drag coefficient and average Nusselt number of each cylinder is plotted versus studied parameters. It is found that the increase in the gap space distance between cylinders increases the heat transfer rate.

scholarly journals Numerical investigation of laminar forced convection heat transfer in rectangular channels with different block geometries using nano-fluids

2017 ◽  
Vol 21 (5) ◽  
pp. 2129-2138 ◽  
Author(s):  
Saeed Foroutani ◽  
Alireza Rahbari
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Forced Convection ◽  
Average Nusselt Number ◽  
Volume Fraction ◽  
Convection Heat Transfer ◽  
Convection Heat ◽  
Forced Convection Heat Transfer ◽  
Triangular Block

This research investigates the laminar steady-forced convection heat transfer of a Cu-water nanofluid in a 2-D horizontal channel with different block geometries attached to the bottom wall. The block geometries assumed in this research are triangular and curve blocks. The governing equations associated with the required boundary conditions are solved using finite volume method based on the SIMPLE technique and the effects of Reynolds number, nanofluid volume fraction, block geometry, and the numbers of blocks on the local and average Nusselt numbers are explored. The obtained results show that nanoparticles can effectively enhance the heat transfer in a channel. Furthermore, the local and average Nusselt number distribution is strongly dependent on the block geometry. As observed, the heat transfer augments with the increase in the Reynolds number and nanofluid volume fraction for both block geometries. It is also concluded that the average Nusselt number of the curve block is higher than that of the triangular block for different Reynolds numbers which declares the importance of the block geometry in the heat transfer enhancement.

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