Numerical Investigation of Forced Convection Heat Transfer from Offset Square Cylinders Placed in a Three Dimensional Confined Channel

2015 ◽  
Vol 813-814 ◽  
pp. 729-735 ◽  
Author(s):  
Paulraj Maheandera Prabu ◽  
Mahadevan Sivasubramanian ◽  
P. Rajesh Kanna ◽  
M. Uthayakumar ◽  
K.P. Padmanaban

Abstract-Flow over two offset square cylinders in a confined channel is simulated for different Reynoldsnumber to reveal the forced convection heat transfer from the heated square cylinders to the ambientfluid. The bottom of the cylinder is maintained at constant temperature. The distance between thecylinder in normal direction as well as transverse direction are fixed as 2d and the blockage ratio is fixedas 0.167. Heat transfer from the cylinders to the ambient fluid as well as conducted within solid wallthrough conjugate interface boundary investigated in connection with Reynolds number are reportedfor both steady and periodic flow. Simulation is carried out for Reynolds number varies from 10 to100 for the fluid as air with Prandtl number as 0.71. The isotherm contours, local Nusselt number andaverage Nusselt number are reported for various Reynolds number. The stagnation zone results higherNusselt number than remaining walls and rear wall results lowest Nusselt number. The downstreamcylinder results higher Nusselt number than the upstream cylinder. The top and bottom surfaceNusselt number from upstream and downstream cylinder are not analogous to single cylinder placed ina channel.

2019 ◽  
Vol 128 ◽  
pp. 07002
Author(s):  
R. Kanna ◽  
Sayed Sayeed Ahmad ◽  
P. Venkata Reddy ◽  
Chithirai Pon Selvan ◽  
Tale ◽  
...  

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.


2017 ◽  
Vol 21 (5) ◽  
pp. 2129-2138 ◽  
Author(s):  
Saeed Foroutani ◽  
Alireza Rahbari

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.


2014 ◽  
Vol 136 (7) ◽  
Author(s):  
C. Y. Wang

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.


Author(s):  
K. Jafarpur ◽  
M. H. Nowzari ◽  
S. M. H. Jayhooni ◽  
A. Abbasi Baharanchi

In the present article, forced convection heat transfer of steady flows pass over staggered square cylinders has been studied numerically. In the tested cases, the passing fluids are nanofluid which has water as base fluid, containing CuO as nanoparticles with different volume fractions. Besides, the flow is laminar and all cylinders are square with constant wall temperature. Recent correlations are used for viscosity and thermal conductivity of nanofluids which are functions of temperature and particle volumetric concentration. Numerical simulations have been performed for low Peclet numbers(Pe ≤ 200), since in this range the flow is steady and laminar. Four different configurations of square cylinders have been studied and the results are compared with each other. This is to investigate the effect of different staggered configurations on forced convection heat transfer inside CuO/Water nanofluids. Finally, a model which has the configuration for the highest heat transfer enhancement inside CuO/Water nanofluids with different particle volume fractions has been specified.


1997 ◽  
Vol 119 (1) ◽  
pp. 70-79 ◽  
Author(s):  
G. Refai Ahmed ◽  
M. M. Yovanovich

Experimental studies of forced convection heat transfer from different body shapes were conducted to determine the effects of Reynolds number and different characteristic body lengths on the area-averaged Nusselt number. Although the bodies differed significantly in their shapes, they had approximately the same total surface area, A = 11,304 mm2 ± 5%. This ensured that for a given free stream velocity and total heat transfer rate all bodies had similar trends for the relationship of Nusselt and Reynolds numbers. The experimental program range was conducted in the Reynolds number range 104≤ReA≤105 and Prandtl number 0.71. Finally, the empirical models for forced convection heat transfer were developed. These empirical models were valid for a wide range of Reynolds numbers 0≤ReA≤105. The present experimental correlations were compared with available correlation equations and experimental data. These comparisons show very good agreement.


Sign in / Sign up

Export Citation Format

Share Document