Local Heat Transfer Characteristics in Simulated Electronic Modules

Yoo, Seong-Yeon; Park, Jong-Hark; Chung, Min-Ho

doi:10.1115/1.1602478

Cited by 5 publications

(3 citation statements)

References 5 publications

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“…Their results show that the installation of an inclined plate above an upstream source results in a periodically unsteady flow and enhances the heat transfer performance. Yoo et al [28] investigated local turbulent heat transfer characteristics in simulated electronic modules with and without vortex generator experimentally, and the rectangular wing type vortex generator has been found to be more effective than the delta wing type vortex generator. In Fu and Tong's [29] two-dimensional, incompressible, and laminar air flow study, a numerical simulation was performed to study the influence of an oscillating cylinder on the heat transfer from heated blocks in a channel flow.…”

Section: Introductionmentioning

confidence: 99%

Cooling of Heated Blocks with Triangular Guide Protrusions Simulating Printed Circuit Boards

et al. 2022

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There is no study that investigates triangular guide protrusions including their systematical geometrical changes together with the effects of channel height in the open literature in the context of the authors’ knowledge. Moreover, the number of laminar studies is less than turbulent studies, whereas low velocity or natural convection cases are still important, especially for small devices in small PCB passages. The objective of this study is to investigate numerically the effects of triangular guide protrusions for the enhancement of heat transfer from the blocks’ simulated electronic components in laminar flow conditions. Two-dimensional, incompressible, steady, and laminar flow analysis was performed to predict fluid flow and heat transfer characteristics for three heated blocks in a PCB (printed circuit board) passage with triangular guide protrusions mounted on the upper wall. The Galerkin finite element method of weighted residuals was used to discretize conservation equations. The effects of the channel expansion ratio and inlet velocity were investigated for five geometrical cases. If the size of the protrusions is increased, the existence of protrusions starts to affect the flow patterns on the lower wall. The size of the last protrusion controls the flow structure downstream of the last block. On the upper wall, after the last protrusion, a recirculation is formed and the length of the recirculation increases with an increasing Re number. Moreover, the reattachment length of recirculation after the last block increases with an increasing Reynolds number for a fixed expansion ratio. Expansion ratio and inflow conditions caused by blocks and protrusions have a great influence on the formation of secondary recirculation in addition to the Reynolds number. Heat transfer increases with increasing sizes of upper triangular protrusions. Maximum overall heat transfer enhancement is provided as 47.7% with the geometry of the maximum sized protrusions for the channel height of 3 h. In the case of 4 h, the maximum overall heat transfer enhancement is 24.21%. These enhancements in heat transfer that can be encountered in PCB cooling applications may help the PCB cooling designers.

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Section: Introductionmentioning

confidence: 99%

Cooling of Heated Blocks with Triangular Guide Protrusions Simulating Printed Circuit Boards

et al. 2022

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“…They showed that thermal insulation of the cavity could be achieved through the use of high velocity horizontal flow. Local heat transfer characteristics in electronics modules were studied by Yoo et al (2003). They indicated that longitudinal vortices formed by vortex generator enhanced the mixing of fluids and thereby heat transfer, and the rectangular wing type vortex generator was found to be more effective that the delta wing type vortex generator.…”

Section: Introductionmentioning

confidence: 99%

Flow over solid blocks in open ended cavity

Shuja

Yilbaş

Khan

2009

International Journal of Numerical Methods for Heat &Amp; Fluid Flow

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Purpose -The purpose of this paper is to consider flow over heat generating bodies in an open-ends cavity, which finds applications in electronics cooling and industrial processing. Heat transfer rates depend on the flow situation in the cavity, which is influenced by the cavity inlet and exit port locations, heat transferring body size and its orientation in the cavity, and the cavity size. Consequently, modeling of flow over heat transferring bodies in an open-ends cavity and examination of the effect of the aspect ratio and orientation of the heat transferring bodies on the flow field and heat transfer rates becomes essential. Design/methodology/approach -The flow over heat generating solid blocks situated in an openends cavity is considered and the effects of blocks' orientations and aspect ratios on flow field as well as heat transfer rates are examined. A numerical scheme using a control volume approach is introduced to predict flow field in the cavity and heat transfer rates from the blocks. Findings -It is found that complex flow structure is generated in the cavity due to the aspect ratios and orientations of the blocks. This, in turn, influences significantly heat transfer rates from the blocks in the cavity. Research limitations/implications -Surface areas of blocks are kept the same and aspect ratio is varied such that the surface area of each block remains the same in the simulations. In addition, Steady flow situation is considered for governing equations of flow and heat transfer in the cavity. However, for the future study transient heating and flow situations can be considered while varying the surface araes of the blocks. This will provide useful information on the circulations in the cavity and the enhancement of heat transfer due to the complex flow structure. Practical implications -In practice, cooling effectiveness can be improved through changing the aspects ratio of the heat generating bodies in the cavity. Originality/value -The findings are original and will be useful for the scientists and the design engineers working the specific area of heat transfer and fluid flow.

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“…by Yoo et al[27] in the Reynolds number range of 1.29 x 10 4 to 3.87xl0 4 (based on channel height) has examined the local heat transfer coefficient in both two-dimensional and three-dimensional module arrays. The two-dimensional module array data showed a little lower value than the three-dimensional results, as a result of bypass flow.…”

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confidence: 99%

Turbulence Modeling of Forced Convection Heat Transfer in Two-Dimensional Ribbed Channels

Elsaadawy

Mortazavi

Hamed

2008

Journal of Electronic Packaging

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The progress of technology in the electronic components industry has been rapidly growing. The evolution of various techniques has made it possible for this industry to grow and diversify with the market demand. Thus, the development of electronic component products over a short span of time requires having highly efficient tools for design and manufacturing. Advances in commercial Computational Fluid Dynamics (CFD) softwares and computational power have enabled modeling to a high level of architectural details. Nowadays, computer aided design becomes an essential design tool in the engineering environment. Computer analysis reduces both the time development cycle and the prototyping costs in the early to intermediate design phases. The accuracy of the computational prediction of heat transfer rates depends mostly on the correct choice of turbulent model. Although many turbulent models, rather than a universal turbulent model, have been developed during the last two decades, there is usually one model that performs better than others for certain flow conditions. In the present research, a turbulence model is selected from amongst a few candidates, namely standard k-8, RNG k-8, shear stress transport (SST), and Reynolds Stress Model (RSM), based on comparisons with experimental data and direct numerical simulation (DNS) results from previous work. The SST turbulence model shows excellent agreement with the DNS results and, hence, is considered an appropriate turbulence model for thermal analysis of electronic packages with elements that have almost the same heights. Moreover, the average Nusselt number of array of obstacles is obtained numerically using commercial code ANSYS-CFX 1 0.0. The effects upon the mean Nusselt number arising from parameteric changes in Reynolds number, element height, element width, and element-to-element distance are compared and discussed. Finally, the parametric study has offered a set of correlations for the mean Nusselt number of arrays of mounted obstacles in the channel flow.lll

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Local Heat Transfer Characteristics in Simulated Electronic Modules

Cited by 5 publications

References 5 publications

Cooling of Heated Blocks with Triangular Guide Protrusions Simulating Printed Circuit Boards

Cooling of Heated Blocks with Triangular Guide Protrusions Simulating Printed Circuit Boards

Flow over solid blocks in open ended cavity

Turbulence Modeling of Forced Convection Heat Transfer in Two-Dimensional Ribbed Channels

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