Comparative study of conjugate heat transfer in a single-phase flow in wavy and raccoon microchannels

Tiwari, Nishant; Moharana, Manoj Kumar

doi:10.1108/hff-05-2019-0439

Cited by 36 publications

(21 citation statements)

References 43 publications

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“…The design and development of efficient heat exchanging systems (Kumar et al , 2016; Pati et al , 2020; Mehta and Pati, 2018, 2020a, 2020b, 2021a, 2021b; Sujith et al , 2021; Tiwari and Moharana, 2019a, 2019b, 2019c, Tiwari et al , 2017) is an important area of research because of its wide range of engineering applications such as solar collector, electro-chemical, geothermal processes and flow boiling (Evangelos et al , 2019; Fahim et al , 2016). In this context, researchers have commonly used two methods for heat transfer enhancement; namely, active and passive ones.…”

Section: Introductionmentioning

confidence: 99%

Analysis of thermo-hydraulic and entropy generation characteristics for flow through ribbed-wavy channel

Mehta

Pati

Ahmed

et al. 2021

HFF

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Purpose The purpose of this study is to analyze the thermal, hydraulic and entropy generation characteristics for laminar flow of water through a ribbed-wavy channel with the top wall as wavy and bottom wall as flat with ribs of three different geometries, namely, triangular, rectangular and semi-circular. Design/methodology/approach The finite element method-based numerical solver has been adopted to solve the governing transport equations. Findings A critical value of Reynolds number (Recri) is found beyond which, the average Nusselt number for the wavy or ribbed-wavy channel is more than that for a parallel plate channel and the value of Recri decreases with the increase in a number of ribs and for any given number of ribs, it is minimum for rectangular ribs. The performance factor (PF) sharply decreases with Reynolds number (Re) up to Re = 50 for all types of ribbed-wavy channels. For Re > 50, the change in PF with Re is gradual and decreases for all the ribbed cases and for the sinusoidal channel, it increases beyond Re = 100. The magnitude of PF strongly depends on the shape and number of ribs and Re. The relative magnitude of total entropy generation for different ribbed channels varies with Re and the number of ribs. Practical implications The findings of the present study are useful to design the economic heat exchanging devices. Originality/value The effects of shape and the number of ribs on the heat transfer performance and entropy generation have been investigated for the first time for the laminar flow regime. Also, the effects of shape and number of ribs on the flow and temperature fields and entropy generation have been investigated in detail.

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Section: Introductionmentioning

confidence: 99%

Analysis of thermo-hydraulic and entropy generation characteristics for flow through ribbed-wavy channel

Mehta

Pati

Ahmed

et al. 2021

HFF

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“…The effect of the wavy channel on the thermal performance, pressure drop, friction factor and wall shear stress is reported. To further improve the heat transfer performances of the microchannel heat sink, the heat transfer enhancement in low Reynolds number flows with wavy walls are reported in these paper (Tiwari and Moharana, 2020;Gong et al, 2016;Aneesh et al, 2018;Rostami et al, 2015;Xia et al, 2019). Results show that these microchannels heat sinks provide better overall thermal performance.…”

Section: Variable Bend Amplitudementioning

confidence: 97%

Numerical analysis of the flow and heat transfer characteristics in serpentine microchannel with variable bend amplitude

Zhang

Liu

2020

HFF

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Purpose This study aims to propose the increase of heat dissipation requirements of modern electronic equipment and the fast development of micro-scale manufacturing technologies. The heat transfer mechanism is studied in-depth, especially for its pattern of secondary flow caused by the repeated inversion of centrifugal force. Effects of η on the frictional pressure drop and average Nusselt number are studied and the performance of such microchannel heat sink with various bend amplitudes is comprehensively evaluated. These results can provide important insight into the optimal design of this novel design configuration for microelectronics cooling. Design/methodology/approach A three-dimensional model based on the finite volume approach and SIMPLEC algorithm is performed to test an innovative serpentine microchannel, which behaves differently from conventional serpentine microchannel due to the significant effect of centrifugal force inversion. Findings The effect of centrifugal force significantly influences the flow and thermal fields which are responsible for the enhancement in heat transfer coefficient. The number, size and intensity of vortices increase with increasing Re, and the vortices are reformed at every change of the geometry in a periodic fashion. The serpentine microchannel studies more effectively at larger bend amplitude. Pressure fluctuations and temperature variation are greater with increasing bend amplitude. Practical implications Several techniques have been developed to augment single-phase convective heat transfer in channels. One technique is to use a serpentine channel that enhances the heat transfer due to flow mixing and periodic interruption of thermal boundary layers. This technique has been applied to micro-heat exchangers, thermal regenerators and mini/microreactors. Social implications The optimal design of this novel design configuration for microelectronics cooling can be attained. It will become an effective cooling technology for solving the increasing of heat dissipation requirements of modern electronic equipment. Originality/value The flow and heat transfer characteristics are first presented for the circular serpentine microchannel made up of alternate U-bends without interposed straight segments. The present study first examines the effect of such centrifugal force inversion on velocity contour, pressure distribution and temperature distribution. The patterns of secondary flow along the flow passage caused by the repeated inversion of centrifugal force are further studied in depth. The effect of bend amplitude on the flow and heat transfer is explored and the performance of such microchannel heat sink has been comprehensively evaluated.

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“…Datta et al 15 employed conjugate heat transfer analysis followed by parametric optimization to find the best suitable geometry that can minimize EG and maximize thermal performance (TP). Tiwari et al 16,17 compared simple raccoon microchannel and modified raccoon microchannel (MRMC). They considered various substrate materials including silicon, SS 316, copper with wall to fluid conductivity ratios ( k sf = 22, 247, and 646) at (Re = 100–200).…”

Section: Introductionmentioning

confidence: 99%

Parametric study of heat transfer performance including entropy generation of microchannel heat sink with fan cavity and different rib structure

Subrahmanyam

Datta

Das

2021

Proceedings of the Institution of Mechanical Engineers, Part E:

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This numerical study investigates the simultaneous application of axial wall conduction effect and entropy generation minimization as two principles to identify heat transfer performance in a microchannel heat sink with fan cavity and ribs. In this conjugate analysis, three different materials for a microchannel heat sink considered are silicon, aluminium, and copper. In addition to the fan cavity (F), effects of different rib configurations arranged symmetrically inside the fan cavity, that is, backward triangle rib (FB), rectangular rib (FR), forward triangle rib (FF), and diamond rib (FD) with Reynolds numbers ranging from 136 to 588 are studied. The comparative study between silicon and copper in terms of local wall and bulk fluid temperatures, increment in solid wall to fluid thermal conductivity ratio within the range (247.07 < ksf < 669.44), local Nusselt number (Nu x), axial conduction number (M), and entropy generation number ( Ns, a) were furnished and examined. Structural optimization is performed on diamond rib configuration geometrical parameters to observe entropy generation number and wall conduction effects trend as thermal performance is greatly improved to 2.49, at the lowest Ns, a to 0.31 at Re 391.47, with copper in the back to back cavities case. However based on the numerical results, comparative importance of axial wall conduction effect consideration in the present design of microsink, silicon is showing best results in overcoming at Re 588.4, consistently in all optimization cases.

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Comparative study of conjugate heat transfer in a single-phase flow in wavy and raccoon microchannels

Cited by 36 publications

References 43 publications

Analysis of thermo-hydraulic and entropy generation characteristics for flow through ribbed-wavy channel

Analysis of thermo-hydraulic and entropy generation characteristics for flow through ribbed-wavy channel

Numerical analysis of the flow and heat transfer characteristics in serpentine microchannel with variable bend amplitude

Parametric study of heat transfer performance including entropy generation of microchannel heat sink with fan cavity and different rib structure

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