Heat transfer characteristics of thermally developing flow in rectangular microchannels with constant wall temperature

Su, Liangbin; Duan, Zhipeng; He, Boshu; Ma, Hao; Ning, Xiaoru; Ding, Guangchao; Cao, Yang

doi:10.1016/j.ijthermalsci.2020.106412

Cited by 20 publications

(6 citation statements)

References 67 publications

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“…Figure 3 shows the variation relationship of Nu ( x ) with ( x * ) 0.5 . It can be evidently observed that the numerical calculation results agree well with the data given in the literature [ 28 , 29 ]. There is only a slight deviation in the inlet section, which is induced by the shrinkage inlet, with a change in the cross-section area where the fluid is accelerated.…”

Section: Model and Methodssupporting

confidence: 86%

“… Variation of local Nusselt numbers with dimensionless axial distance for different research. The numerical results are almost identical to those in other literatures [ 28 , 29 ]. …”

Section: Figuresupporting

confidence: 87%

“…To characterize the thermal effects on the flow, the local Nusselt number ( Nu ( x )) is investigated, especially in the section of fully-developed thermal boundary layers [ 27 , 28 ]. The local Nusselt number ( Nu ( x )) is expressed in Equations (5)–(7), referring to research carried out by Su et al [ 28 ] and Shah et al [ 29 ]. The results are compared with the Nusselt number of the fluid in the microchannel described above.…”

Section: Model and Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Flow Characteristics and Switching Mechanism of Bistable Slit Flow Actuated by Temperature

Nie

et al. 2023

Entropy

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The bistable flow is attractive as it can be analogous to a switch to realize flow control. Based on the previous studies on actuation technique, the present study first proposed temperature-driven switching of bistable slit flow. A two-dimensional numerical simulation was conducted to investigate the flow deflection characteristics and switching mechanism. It was concluded that the temperature gradient not only biases the slit flow but also locks it to the high-temperature side. The flow deflection angle became larger with the increase in temperature gradient. Being driven by the temperature, the flow can be switched from one side to the other. Furthermore, the fluid viscosity, which varies with temperature, determines the degree of flow deflection and the entire switching time. This research can enrich the active regulation of flow and has significant potential applications in thermal sensors, thermal detectors, microelectromechanical systems, biomedicine, and other equivalent fields.

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Section: Model and Methodssupporting

confidence: 86%

“… Variation of local Nusselt numbers with dimensionless axial distance for different research. The numerical results are almost identical to those in other literatures [ 28 , 29 ]. …”

Section: Figuresupporting

confidence: 87%

Section: Model and Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Flow Characteristics and Switching Mechanism of Bistable Slit Flow Actuated by Temperature

Nie

et al. 2023

Entropy

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“…Rajalingam A [ 10 ] investigated the effects of microstructure in microchannel heat sinks. Su [ 11 ] used numerical simulation to study the three-dimensional heat transfer problem at the entrance of a small rectangular channel at a constant wall temperature. Yao et al [ 12 ] studied the heat transfer and service life of the new W-type micro/small channel heat exchanger.…”

Section: Introductionmentioning

confidence: 99%

Numerical study on flow and heat transfer characteristics of rectangular mini-channel of interpolated double S turbulators

Xi,

Meng

2024

PLoS ONE

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In this study, we propose a new type of small-channel plug-in, the double S turbulators, for passive heat transfer enhancement to improve the flow and heat transfer performance of the fluid in the channel. In the range of Reynolds number 254.51~2545.09, under constant wall temperature heating conditions, the effects of interpolated double S turbulators with different long axial radii (1mm, 1.5mm, 2mm) on the average Nusselt number, pressure drop, total thermal resistance and field synergy number in the rectangular mini-channel were studied. The simulation results show that compared with the smooth rectangular mini-channel, after interpolating double S turbulators with different long axial radii (1mm, 1.5mm, 2mm), the average Nusselt number increased by 81.74%~101.74%, 71.29%~94.06%, 67.16%~88.48%, the total thermal resistance decreased by 45.1%~50.72%, 41.72%~48.74%, 40.28%~47.2%, and the number of field synergies increased by 85.58%~111.65%, 74.1%~102.6%, 69.64%~96.12%. At present, there are few studies on the boundary condition of constant wall temperature, and this paper supplements the research on this aspect. At the same time, the heat transfer performance of the rectangular mini-channel of the interpolated double S turbulators is stronger than that of the ordinary smooth rectangular mini-channel, which not only provides a new idea for the manufacture of micro heat dissipation equipment, but also improves the heat transfer performance of micro heat dissipation equipment and improves its work efficiency. According to the simulation data, the prediction formula of average Nusselt number and pressure drop was established by nonlinear regression method, which can be used to predict the flow and heat transfer characteristics of the rectangular mini-channel of the interpolated double S turbulators.

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“…Many studies have focused on optimizing the specific parameters that affect microchannel performance in an effort to boost overall performance. Circular [19], rectangular [20], square [21], and triangular [22] cross-sections have all been taken into account, as well as water [23], air [24], and nanofluids [25] as working fluids, silicon [26] and copper [27] as materials, and staggered [28], porous [29], ribbed [30], and sinusoidal [31] as roughnesses of the surface. At present, the majority of studies aim to understand the effects of specific factors on the performance of microchannels.…”

Section: Introductionmentioning

confidence: 99%

Thermo-Hydraulic Management System Employing Single-Phase Water Flow through Microchannels with Micro-Inserts Added Aiming for Performance Improvement

Kumar

Singh

2023

Processes

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A microchannel heat exchanger effectively evacuates heat from a confined space. This paper attempts to gain insight into the combinatorial repercussions of simultaneously coupling two factors that affect a microchannel’s performance, of which channel size and micro-insert complexity are the two main contributors. With water as the working fluid, an ANSYS-based numerical analysis was carried out for two distinct channel sizes, 1 and 2 mm, both with and without micro-inserts. The Reynolds numbers varied between 125 and 4992 and between 250 and 9985 for the 1 and 2 mm channels, respectively. For the 2 mm diameter channel, adding micro-inserts raised the overall pressure drop with increased Reynolds number. The inclusion of micro-inserts increased the pressure drop in the 1 mm channel at first, and thereafter the pressure drop decreased. Incorporating micro-inserts into the channel resulted in enhanced heat transfer. The trade-off between enhanced heat transfer performance and a larger pressure drop was calculated by evaluating the channel’s overall performance using the thermal performance factor. Micro-inserts were found to be most useful for improving overall performance in the low-to-moderate Reynolds number range, and their effectiveness increased with decreasing channel size. Changing the channel diameter and structure of the design can improve heat transmission through microchannels.

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Heat transfer characteristics of thermally developing flow in rectangular microchannels with constant wall temperature

Cited by 20 publications

References 67 publications

Flow Characteristics and Switching Mechanism of Bistable Slit Flow Actuated by Temperature

Flow Characteristics and Switching Mechanism of Bistable Slit Flow Actuated by Temperature

Numerical study on flow and heat transfer characteristics of rectangular mini-channel of interpolated double S turbulators

Thermo-Hydraulic Management System Employing Single-Phase Water Flow through Microchannels with Micro-Inserts Added Aiming for Performance Improvement

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