Numerical study of TiO2-based nanofluids flow in microchannel heat sinks: Effect of the Reynolds number and the microchannel height

Martínez, Víctor A.; Vasco, Diego A.; García‐Herrera, Claudio; Ortega, Roberto A.

doi:10.1016/j.applthermaleng.2019.114130

Cited by 52 publications

(15 citation statements)

References 36 publications

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“…These modern fluids, called NFs, have been introduced in 1995 by Choi [1] and have attracted the attention of various researchers around the world for their interesting thermal properties [2][3][4][5][6][7]. The cooling performance of NFs has been investigated in various heat transfer systems such as photocatalysts [8][9][10], membranes [11][12][13], heat sinks [14][15][16] and electrodes [17][18][19], and the results have shown that mainly the use of NF has improved the performance of these systems. One of the cases in which the potential of NFs has been examined is the problem of free convection heat transfer in concentric and eccentric annuli.…”

Section: Introductionmentioning

confidence: 99%

RETRACTED: Free convection of non‐Newtonian nanofluid flow inside an eccentric annulus from the point of view of first‐law and second‐law of thermodynamics

et al. 2020

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The current work aims to perform the hydrothermal and entropy generation (EG) characteristics in a naturally cooled eccentric horizontal annulus filled with non‐Newtonian water‐magnetite/CNT nanofluid (NF). The wall temperature of both cylinders is constant and the temperature of the outer cylinder is lower than that of the inner cylinder. The impacts of vertical eccentricity, nanoadditive concentration (φ) and Rayleigh number (Ra) on the first and second‐laws performance features of the annulus are investigated numerically. It was found the average Nusselt number (Nu), the global thermal EG (TEG) and the global frictional EG (FEG) augment with boosting both the Ra and φ. In addition, it was depicted that the negative eccentricity is desirable and undesirable from the perspective of the first and second‐laws of thermodynamics. Moreover, the outcomes revealed that the first‐law/second‐law performance of the aqueous magnetite/CNT NF is better/weaker than that of the aqueous magnetite NF. Furthermore, for all the examined cases, the TEG rates are much higher than the FEG rates, and as a result, the pattern of total EG changes follows the TEG. Among all the studied cases, the minimum total EG was 4 W/K, which belonged to the case of φM= 0.9%, φCNT= 0%, Ra= 103 and e= 0.001.

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Section: Introductionmentioning

confidence: 99%

RETRACTED: Free convection of non‐Newtonian nanofluid flow inside an eccentric annulus from the point of view of first‐law and second‐law of thermodynamics

et al. 2020

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“…Therefore, the laminar model was selected for 1 cell, and the turbulent model was set for the stacks with 5 cells or over this number of cells. [27][28][29] The influence of gravity is ignored, and the flow is incompressible. Each stack is divided into two non-porous zones and porous medium zones.…”

Section: Theoretical Modelmentioning

confidence: 99%

Flow field simulation and pressure drop modeling by a porous medium in PEM fuel cells

Chen

Tsai

Chang

et al. 2020

Intl J of Energy Research

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For proton-exchange membrane fuel cells, the distribution of reactant flow in the stack is critical to the fuel cell's efficiency. The uneven distribution of reactant flow in the stack may cause poor current density, low performance, and material degradation. To understand and accurately predict the flow field in the proton-exchange membrane fuel cell system, the present study aims to develop a simple correlation to analyze the pressure drop in fuel cell stacks.The flow channel in each cell of a stack is treated as a porous medium, and a power-law model is used to approximate the porous medium momentum source term. For the stacks with fewer cell numbers, namely, 1, 5, and 10 cells, the parameters in the power law are established based on the experimental data. Then, a correlation is developed to simulate the flow and predict the pressure drop in the stack with higher cell numbers (ie, 20 and 40 cells). The simulations show that the pressure drop in each cell of a stack is almost invariable, and the average pressure drop decreases with increasing the number of cells. The flow uniformity in the stacks with different cell numbers is evaluated using the dimensionless pressure drop and the pressure drop ratios. It suggests that the lower the cell number, the more uniform the pressure drop. The developed model is conducive to efficiently designing the flow channel for a fuel cell stack with large cell numbers.

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“…There are numerous research articles available in the literature 13–52 attributed to fluid flow and heat transfer characteristics of nanofluid in microchannels as well as MCHS. Vafaei and Wen 13,14 experimentally measured the effect of nanoparticle concentration (1-7vol.%) and volume flow rate (8-20ml/min) on fluid flow and heat transfer characteristics of Al2O3/water nanofluid in a circular microchannel (Di=510μm,t=160…”

Section: Introductionmentioning

confidence: 99%

“…Martinez et al. 49 numerically investigated the effect of nanoparticle concentration (1.0 3.0wt.%), Reynolds number (200≤Re≤1200) and height of microchannel (800-400μm) on fluid flow and heat transfer characteristics of TiO 2 /water nanofluid in a rectangular MCHS (Dh=418.10-331.48μm, and L=50mm) at a constant heat flux of 500kW/m2. The results showed that the maximum enhancements in skin friction coefficient and convective HTC were achieved about 137.68% and 19.66%, respectively, at Reynolds number of 200, for TiO 2 /water nanofluid with nanoparticle concentration of 3.0wt.% as compared to DW.…”

Section: Introductionmentioning

confidence: 99%

“…Based upon the aforementioned research articles available in the literature, it was noticed that most of the research articles 13–52 performed parametric study on fluid flow and heat transfer characteristics of nanofluid in a microchannel as well as MCHS. However, correlations of friction factor and average Nusselt number of nanofluid were proposed in a few research articles 17,25,26,47,52 under specified fluid flow and heat transfer conditions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Single-phase fluid flow and heat transfer characteristics of nanofluid in a circular microchannel: Development of flow and heat transfer correlations

Lodhi

Sheorey

Dutta

2020

Proceedings of the Institution of Mechanical Engineers, Part C:

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The convective heat transfer in microchannels with the use of nanofluids has proved to be a potential candidate for cooling of micro-electromechanical system devices. The current research article presents the experimental study on fluid flow and heat transfer characteristics of [Formula: see text]/water nanofluid in a microchannel under thermally developing laminar flow at Reynolds number ranging from 300 to 1000. The experimental set-up of a circular microchannel test section with an inner diameter of [Formula: see text] and length of [Formula: see text] is fabricated to conduct the experimental study. The effect of nanoparticle concentration ([Formula: see text]), Reynolds number ([Formula: see text]) on fluid flow and heat transfer characteristics of [Formula: see text]/water nanofluid have been measured and compared with that of distilled water (DW). The results indicate that the maximum enhancement in local heat transfer coefficient is achieved up to [Formula: see text], while friction factor is achieved up to [Formula: see text] for [Formula: see text]/water nanofluid with nanoparticle concentration of [Formula: see text] as compared to DW. The results showed that the performance evaluation criterion of [Formula: see text]/water nanofluid is greater than unity ([Formula: see text]), implying the benefits of nanofluids as compared to DW. Moreover, the predicted data obtained by the present proposed correlations for friction factor and local Nusselt number using [Formula: see text]/water nanofluid show reasonably good agreement with the deviations of [Formula: see text] and [Formula: see text], respectively, with the numerical data as compared to the predicted data obtained by the existing correlations available in the literature.

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Numerical study of TiO2-based nanofluids flow in microchannel heat sinks: Effect of the Reynolds number and the microchannel height

Cited by 52 publications

References 36 publications

RETRACTED: Free convection of non‐Newtonian nanofluid flow inside an eccentric annulus from the point of view of first‐law and second‐law of thermodynamics

RETRACTED: Free convection of non‐Newtonian nanofluid flow inside an eccentric annulus from the point of view of first‐law and second‐law of thermodynamics

Flow field simulation and pressure drop modeling by a porous medium in PEM fuel cells

Single-phase fluid flow and heat transfer characteristics of nanofluid in a circular microchannel: Development of flow and heat transfer correlations

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