Turbulent flow and heat transfer enhancement of mixed convection over heated blocks in a channel

Abstract

PurposeTo investigate the heat transfer enhancement performed by installing a rectangular plate turbulator for internal flow modification induced by vortex shedding.Design/methodology/approachThe large eddy simulation (LES) and SIMPLE‐C method coupled with preconditioned conjugate gradient methods have been applied to the turbulent flow field and heat transfer enhancement of mixed convection in a block‐heated channel.FindingsProvides information about heat transfer performance indicating that heat transfer performance can be affected by various width‐to‐height ratio of turbulator and Grasehof numbers with a constant Reynolds number. The results show that the installation of turbulator in cross‐flow above an upstream block can effectively enhance the heat transfer performance by suitable width‐to‐height ratio of turbulator and Grasehof numbers.Research limitations/implicationsIt is limited to two‐dimensional mean flow for the turbulent vortex‐shedding flow past a long square cylinder.Practical implicationsA very useful source of information and favorable advice for people developing heat transfer enhancement for electronic devices.Originality/valueThe results of this study may be of interest to engineers attempting to develop thermal control of electronic devices and to researchers interested in the turbulent flow‐modification aspects of heat transfer enhancement of mixed convection in a vertical channel.

Experimental and Numerical Investigation of Turbulent Natural Convection Flow in a Vertical Channel With a Heated Obstacle

“…Results also specify significant diffusion rates of the verti cal mean velocity component and normal Reynolds stress towards channel center. Wu and Pemg [19] presented an unsteady turbu lent flow and mixed convection heat transfer numerical study in a vertical block-heated channel with and without a rectangular turbulator above an upstream block. Their study aims at enhance heat transfer performance.…”

Numerical Study of Turbulent Heat Transfer in a Horizontal Channel Provided With Square Blocks: Effect of the Inter Blocks Spacing

“…The heat transfer problem is important because of its many industrial applications, like cooling of electronic systems, aeronautics and compact heat exchangers [1][2][3][4]. Literature survey shows that most of the existing studies of turbulent flow in horizontal channel with an internal arrangement of rectangular blocks are related to forced or mixed convection phenomenon [5][6][7][8] for the objective of improving the heat transfer rate and the understanding of the fundamental flow interactions mechanisms occurring in various industrial technologies. However, many investigations focused on the modeling and optimization of mounted bars and fins along the channel walls to determine the optimum fin height, aspect ratio and spacing between the blocks to obtain a maximum thermal dissipation.…”

“…However, both models were unable missing some other details of the flow behavior. Perng and Wu [5] conducted numerical study on heat transfer enhancement for turbulent mixed convection flow in horizontal block-heated channel. The Large Eddy Simulation (LES) was used and SIMPLEC algorithm was considered for the velocity-pressure coupling.…”

LBM-MRT simulation of vertical flow of a non-Newtonian fluid in a channel provided with obstacles

“…As an example, Alves and Altemani [4] investigated the factors influencing the forced convection cooling of sources on a printed circuit board, concluding that the dimensions of the sources and their arrangement on the plate exert high influence on the flow behavior and consequently the heat exchange. As a consequence of this importance, several works related to heat exchangers with fins or obstacles can be found for vertical channels [5][6][7][8][9][10][11] and horizontal channels [12][13][14][15]. Sun et al [16] aims at showing that to prescribe a flow rate at the inlet section of a vertical channel with heated walls leads to surprising and counter-intuitive physical solutions, especially when the problem is modelled as elliptical.…”