The Effects of Different Pin-Fin Arrays on Heat Transfer and Pressure Loss in a Narrow Channel

Siw, Sin Chien; Fradeneck, Austen; Chyu, Minking K.; Alvin, Mary Anne

doi:10.1115/gt2015-43855

Cited by 12 publications

(5 citation statements)

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“…Lyall et al [8] and Lawson et al [9] contributed discussions on Reynolds number effects on both the heat transfer and the pressure drop; an increase in Reynolds number generated higher heat transfer. Siw et al [10] investigated narrow pin fin channels, where wall effects were influential, and found much increased heat transfer performance when compared to a conventional, wide pin fin array.…”

Section: Literature Reviewmentioning

confidence: 99%

Pressure loss and heat transfer performance for additively and conventionally manufactured pin fin arrays

Kirsch

Thole

2017

International Journal of Heat and Mass Transfer

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Pin fin heat exchangers represent a common, viable means of keeping components cool and are widely used for electronics cooling and turbine airfoil cooling. Advancements in manufacturing technology will allow these heat exchangers to be built using new methods, such as laser powder bed fusion, a form of additive manufacturing. New manufacturing approaches, however, render a direct comparison between newly and conventionally manufactured parts meaningless without a good understanding of the difference in the performance. This research study investigated microchannel pin fin arrays that were manufactured using Laser Powder Bed Fusion and compared them to studies of pin fin arrays from the literature, which are representative of traditionallymanufactured pin fin arrays, where the pin and endwall surfaces exhibited much lower surface roughness. Pin fin arrays with four different spacings were manufactured and tested over a range of Reynolds numbers; pressure loss and heat transfer measurements were taken. Additionally, the test coupons were evaluated nondestructively and the asbuilt geometric features were analyzed. Measured surface roughness was found to be extremely high in each one of the microchannel pin fin arrays and was found to be a function of the pin spacing in the array, as was the shape of the pin itself; with more pins in the array came higher surface roughness and more distorted pin shapes. Comparisons between the smooth pin fin arrays from literature and the rough pin fin arrays from the current study showed that the high surface roughness more strongly affected the friction factor augmentation than it did the heat transfer augmentation relative to the smooth pin fin arrays.

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Section: Literature Reviewmentioning

confidence: 99%

Pressure loss and heat transfer performance for additively and conventionally manufactured pin fin arrays

Kirsch

Thole

2017

International Journal of Heat and Mass Transfer

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“…Flow travelling through arrays of pedestals can undergo high pressure loss due to the wakes generated behind the pedestals. Research by Chyu et al [6] and Siw et al [7] showed that staggered arrays of pedestals caused much greater pressure drops than inline arrays. The pedestal shape can also have a large influence-cylindrical pedestals produce less pressure loss than those of square or diamond (square rotated by 45°) shapes [6], but also produce lower HTCs.…”

Section: Double-wall Effusion Cooling Systemsmentioning

confidence: 99%

A Low Order Flow Network Model for Double-Wall Effusion Cooling Systems

Noort

Ireland

2022

IJTPP

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The high pressure turbine nozzle guide vane of a modern aeroengine experiences large heat loads and thus requires both highly effective internal and external cooling. This can be accomplished with double-wall effusion cooling, which combines impingement, pin-fin and effusion cooling. The combination of three cooling mechanisms causes high pressure losses, increasing potential for the migration of coolant towards low pressure regions, subsequently starving effusion holes on the leading edge of coolant supply. This paper presents a low order flow network model to rapidly assess the pressure and mass flow distributions through such cooling schemes for a flexible set of geometric and flow conditions. The model is subsequently validated by a series of experiments with varying mainstream pressure gradients. Results from the model are used to indicate design parameters to reduce the effect of coolant migration, and to minimise the risk of destructive hot gas ingestion.

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“…The corresponding friction factor f o 26 for a smooth channel is calculated using the Blasius equation,…”

Section: Data Reductionmentioning

confidence: 99%

“…With thermal enhancement approximately 2.5 to fourfold than a smooth channel, the increased pressure loss is moderate, as asserted by the author. 26 In another comparison study, Hussam et al reported that circular promoter performed the worst among the three shapes regardless of the flow condition of a flow of electrically conducting fluid. The flow is obstructed by circular, rectangular, and triangular to enhance heat transfer while the wall is under a magnetic field.…”

Section: Introductionmentioning

confidence: 98%

See 1 more Smart Citation

Spatial effect of a vertical multi-faceted rib on thermal performance and flow characteristics in a square channel

Amir

Ir.

2022

Proceedings of the Institution of Mechanical Engineers, Part C:

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A multi-faceted vertical rib has been numerically investigated using the internal flow of rib in a rectangular channel method under turbulent flow for 17,000 < Re < 27,000. The vertical rib that can be encountered inside porous media design often creates a persisting issue of high-pressure drop. The challenge frequently intensifies, mainly when a two-phase state heat transfer is introduced inside the porous media. The vertical multi-faceted rib models the various surfaces often encountered inside the porous media. The effect of blockage ratio on the flow characteristics and thermal performance is observed. The results are compared to the more conventional circular rib, equal in surface area to the multi-faceted rib. The multi-faceted rib yields a higher average Nusselt number of approximately 33% and contributes to the higher average Nusselt number of the channel. The multi-faceted rib channel has a better thermal performance factor, in average of approximately 13% higher and lower pressure drop than the circular rib channel. The advantage of the multi-faceted rib is attributed to, surprisingly, the poor flow attachment on the rib surface, which results in a low Cf/ f ratio. Consequently, the multi-faceted rib suffers from very low velocity on the downstream rib surface. Ultimately, the spatial effect of the rib inside the square channel can be evaluated using the Cf/ f ratio, which takes into account the rib surface and channel walls. In the quasi two-phase state, the circular rib is observed to provide a more favorable condition for latent heat transfer under extreme condition investigated.

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The Effects of Different Pin-Fin Arrays on Heat Transfer and Pressure Loss in a Narrow Channel

Cited by 12 publications

References 0 publications

Pressure loss and heat transfer performance for additively and conventionally manufactured pin fin arrays

Pressure loss and heat transfer performance for additively and conventionally manufactured pin fin arrays

A Low Order Flow Network Model for Double-Wall Effusion Cooling Systems

Spatial effect of a vertical multi-faceted rib on thermal performance and flow characteristics in a square channel

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