Optimization of an inclined elliptic impinging jet with cross flow for enhancing heat transfer

Heo, Man-Woong; Lee, Ki‐Don; Kim, Kwang‐Yong

doi:10.1007/s00231-011-0763-2

Cited by 33 publications

(5 citation statements)

References 18 publications

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“…This turbulence model has also been employed to accurately predict flow problems near stationary wall [19,20]. The boundary conditions were specified the same with the experiment conditions.…”

Section: Numerical Simulationmentioning

confidence: 99%

Heat transfer characteristics in a channel fitted with zigzag-cut baffles

et al. 2015

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The heat transfer characteristics were experimentally investigated in a wind channel with different types of cut baffles for heat transfer augmentation. The aim of using zigzag-cut baffles is to create 3D flow structure behind the baffles instead of transverse vortex flow leading to enhance heat transfer. In this study, 4 types of baffles were examined; conventional baffle (Rectangular cross section with no cut), baffle with rectangular zigzag-cut, baffle with triangle zigzag-cut at 45 degree and at 90 degree. All of the baffles have the same height at H = 15 mm and flow blocking area. In the experiment, the row of seven baffles was attached on the inner surface of wind channel. The effects of pitch spacing length were also investigated at baffle pitch distance P/H = 4, 6 and 8 (H: Height of baffle). The experiments were performed at constant Reynolds number (Re) of 20000. The heat transfer patterns via Thermochromic liquid crystal sheet were visualized and recorded with a digital camera. The recorded images were then analyzed with image processing technique to obtain the distribution of Nusselt number. The flow characteristics pass through the baffles were also numerically studied with CFD simulation for understanding the heat transfer characteristics. The friction losses were measured to evaluate the thermal performance for each baffle. It was found that the baffle with rectangular zigzag-cut gives the best thermal performance due to heat transfer augmentation in upstream and downstream side of baffle.

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Section: Numerical Simulationmentioning

confidence: 99%

Heat transfer characteristics in a channel fitted with zigzag-cut baffles

et al. 2015

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“…They examined the effects of d, H/d, l/d, and the flow rate on heat transfer and proposed correlations based on the jet Reynolds number. Heo et al (2011) investigated an inclined elliptic jet for cross-flow analysis through numerical methods, observing that the size of the recirculation region just upstream of the jet and the length of the potential core of the jet significantly affect the heat transfer process.…”

Section: Introductionmentioning

confidence: 99%

Performance Analysis of a Multiple Micro-Jet Impingements Cooling Model

et al. 2016

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The present study investigates the thermal performance of a multiple micro-jet impingements model for electronics cooling. The fluid flow and heat transport characteristics were investigated for steady incompressible laminar flow by solving three-dimensional (3D) Navier-Stokes equations. Several parallel and staggered micro-jet configurations (ie. inline 2 Å~ 2, 3 Å~ 3 and 4 Å~ 4 jets, and staggered five-jet and 13-jet arrays with the jet diameter to the channel height ratios from 0.25–0.5) were analyzed at various flow rates for the maximum temperature rise, pressure drop, heat-transfer coefficient, thermal resistance, and pumping power characteristics. The parametric investigation was carried out based on the number of jets and the jet diameters at various mass flow rates and jet Reynolds numbers. Temperature uniformity and coefficient of performance were evaluated to find out the trade-off among the various designs investigated in the present study. The maximum temperature rise and the pressure drop decreased with an increase in the number of jets except in the case of staggered five-jet array. A higher temperature uniformity was observed at higher flow rates with a decrease in the coefficient of performance. The performance parameters, such as thermal resistance and pumping power, showed a conflicting nature with respect to design variables (viz. jet diameter to stand-off ratio and interjet spacing or number of jets) at various Reynolds numbers within the laminar regime.

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“…However, systematic numerical optimization techniques [5] hardly have been applied to the geometries of microchannels with phase change to enhance heat transfer. Numerical optimization techniques coupled with Reynolds-averaged Navier-Stokes (RANS) analysis of fluid flow and heat transfer are being widely applied to designs of various thermo-fluid systems to improve their performance [6][7]. The aims of the present work are to investigate the effects of the three design variables on the heat transfer characteristics in microchannels and to optimize the geometry of the microchannels to improve the performance of heat transfer with phase change.…”

Section: Introductionmentioning

confidence: 99%

Shape Optimization of a Microchannel Heat Sink with Phase Change

Heo

Choi

Kim

2013

AMM

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Optimization of a microchannel heat sink has been performed based on the analyses of fluid flow and heat transfer with phase change using three-dimensional Reynolds-averaged Navier-Stokes equations. The uniform heat flux condition is applied at the bottom of the heat sink. Three design variables, viz. ratio of microchannel width to height of the heat sink, ratio of fin height to heat sink height, and ratio of fin width to height of the heat sink are selected for the shape optimization. Latin hypercube sampling was used to determine the training points as a design of experiment, and the surrogate model is constructed using the objective function values at the training points. Sequential quadratic programming is used to search for the optimal point from the constructed surrogate model. The thermal resistance is set as the objective function. It was found that the thermal resistance increased with increasing ratios of the microchannel width-to-height of the heat sink and fin height to heat sink height, while the thermal resistance decreased with increasing ratio of the fin width-to-height of the heat sink. Through the optimization, the thermal resistance has been decreased by 37.3% compared to the reference geometry.

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Optimization of an inclined elliptic impinging jet with cross flow for enhancing heat transfer

Cited by 33 publications

References 18 publications

Heat transfer characteristics in a channel fitted with zigzag-cut baffles

Heat transfer characteristics in a channel fitted with zigzag-cut baffles

Performance Analysis of a Multiple Micro-Jet Impingements Cooling Model

Shape Optimization of a Microchannel Heat Sink with Phase Change

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