Measurement of two-dimensional heat transfer and flow characteristics of an impinging sweeping jet

This paper presents the numerical predictions of heat transfer and fluid flow characteristics for natural convection in a vertical channel with two-dimensional protruding heat-flux module as applied to the cooling of electronic components. The investigation is for a configuration consisting of a single module mounted on a vertical adiabatic wall. An attempt was made to combine the temperature of the module for all the dimensions of the module into a single composite correlation, along with the numerical data.

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Computational Fluid Dynamics and Heat Transfer Analysis for a Novel Heat Exchanger

Journal of Heat Transfer ◽

10.1115/1.4029764 ◽

2015 ◽

Vol 137 (5) ◽

Cited By ~ 8

Author(s):

Haolin Ma ◽

Dennis E. Oztekin ◽

Seyfettin Bayraktar ◽

Sedat Yayla ◽

Alparslan Oztekin

Keyword(s):

Heat Transfer ◽

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Heat Exchanger ◽

Turbulent Flows ◽

Flow Structure ◽

Three Dimensional ◽

Flow Characteristics ◽

Heat Transfer Analysis ◽

Two Dimensional

Computational fluid dynamics (CFD) and heat transfer simulations are conducted for a novel heat exchanger. The heat exchanger consists of semi-circle cross-sectioned tubes that create narrow slots oriented in the streamwise direction. Numerical simulations are conducted for Reynolds numbers (Re) ranging from 700 to 30,000. Three-dimensional turbulent flows and heat transfer characteristics in the tube bank region are modeled by the k-ε Reynolds-averaged Navier–Stokes (RANS) method. The flow structure predicted by the two-dimensional and three-dimensional simulations is compared against that observed by the particle image velocimetry (PIV) for Re of 1500 and 4000. The adequate agreement between the predicted and observed flow characteristics validates the numerical method and the turbulent model employed here. The three-dimensional and the two-dimensional steady flow simulations are compared to determine the effects of the wall on the flow structure. The wall influences the spatial structure of the vortices formed in the wake of the tubes and near the exit of the slots. The heat transfer coefficient of the slotted tubes improved by more than 40% compare to the traditional nonslotted tubes.

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Instantaneous and Time-Averaged Flow Structure around Two Heated Square Cylinders in the Laminar Flow Regime

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.110-116.2896 ◽

2011 ◽

Vol 110-116 ◽

pp. 2896-2902

Author(s):

Amin Etminan ◽

Abazar Barzegar

Keyword(s):

Heat Transfer ◽

Reynolds Number ◽

Laminar Flow ◽

Flow Characteristics ◽

Reynolds Numbers ◽

Viscous Drag ◽

Two Dimensional ◽

Number Range ◽

Pressure Coefficients ◽

Square Cylinders

In this paper, the flow characteristics and heat transfer over two equal square cylinders which are placed in tandem arrangement, are investigated numerically. The simulations are performed for a Reynolds number range varying from 1 to 200 and spacing between the cylinders is five widths of the cylinders. The calculations are carried out on a finite volume code for both steady and unsteady incompressible laminar flow in the two dimensional regime. In this study, the instantaneous and mean streamlines and isotherm patterns for different Reynolds numbers are presented. In addition, the effect of Reynolds number on the flow patterns around the cylinders are in detail presented. In addition, the quantities such as pressure and viscous drag coefficients and pressure coefficients are presented.

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Heat Transfer and Flow Characteristics of Two-Dimensional Jets Impinging on Heated Protrusions With Crossflow of the Spent Air

Journal of Electronic Packaging ◽

10.1115/1.2905445 ◽

1992 ◽

Vol 114 (1) ◽

pp. 81-87 ◽

Cited By ~ 3

Author(s):

G. L. Whidden ◽

J. Stevens ◽

B. W. Webb

Keyword(s):

Heat Transfer ◽

Flow Structure ◽

Turbulent Transport ◽

Flow Characteristics ◽

Jet Impingement ◽

Local Heat Transfer ◽

Local Heat ◽

Laser Doppler Velocimeter ◽

Two Dimensional ◽

Turbulent Flow Structure

The flow structure and local heat transfer characteristics of two-dimensional slot jets impinging on heated protrusions has been investigated. The spent air was constrained to exit at one end of the channel, forming a crossflow. The effects of three parameters on the heat transfer were examined for an array of five protruding heat sources. They include the jet slot width, distance between the jet exit and the protrusion, and the average jet Reynolds number. Laser-Doppler velocimeter measurements were made to detail the mean and turbulent flow structure in the channel. Experimental results reveal that the flow and heat transfer are dominated by turbulent transport even for Reynolds numbers as low as 300. Two transport mechanisms were identified affecting the heat transfer. The first was jet impingement, the second being crossflow of the spent air. A complex interaction between the two mechanisms was observed. At low nozzle-protrusion spacing with large slot jets the heat transfer was dominated by the crossflow, whereas for high nozzle-protrusion spacing and small jets, transport was dominated by jet impingement. It is postulated that the highest average Nusselt number occurs when the jets and the crossflow influence act with near-equal intensity.

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