Simulation of Evaporation Heat Transfer in a Rectangular Microchannel

Vivekanand, S. V. B.; Raju, V. Ramachandra

doi:10.1016/j.proeng.2015.11.374

Cited by 9 publications

(4 citation statements)

References 10 publications

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“…The comparison of the vapor volume fraction generated along the microchannel can be seen in Figure 3 for the case with prescribed temperature in the walls and constant heat flux, Figure 3(a) and 3(b), respectively. It can be seen that the present study was able to achieve results very similar to those of Vivekanand & Raju (2015), with differences of less than 4 % being observed in the two cases. It is worth mentioning that the difference in the modeling of Vivekanand & Raju (2015) in comparison with the present model is the use of Volume of Fluid (VOF) method to tackle with the two phase flow Therefore, the model employed in this study is considered adequate to simulate microchannels subjected to boiling flows in the laminar regime.…”

Section: Numerical Modelingsupporting

confidence: 77%

“…It was also observed that a mesh with triangular volumes and extra refinement closer to the walls (Figure 2) was able to provide better convergence as it captured better the heat transfer phenomenon, especially in the cases with phase change. To verify the numerical model employed in this study, a comparison was made with the results obtained in the numerical work of Vivekanand & Raju (2015), where a similar microchannel, with 0.1 and 1.0 mm of height and length, respectively, and without the trapezoidal blocks, was subjected to laminar boiling flows. Authors studied the microchannel in two different situations: with fixed temperature in the walls and with constant heat flux in the walls.…”

Section: Numerical Modelingmentioning

confidence: 99%

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Geometrical investigation of microchannel with two trapezoidal blocks subjected to laminar convective flows with and without boiling

et al. 2022

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Microchannels are important devices to improve the heat exchange in several engineering applications as heat, ventilation and air conditioning, microelectronic cooling, power generation systems and others. The present work performs a numerical study of a microchannel with two trapezoidal blocks subjected to laminar flows, aiming to analyze the influence of the boiling process on the geometric configuration of the microchannel. Constructal Design and Exhaustive Search are used for the geometrical evaluation of the blocks. The Mixture multi-phase model and the Lee phase change model were both employed for the numerical simulation of the boiling process. In this study, the influence of the height and higher width of the first block (H11/L11) over the heat transfer rate and pressure drop for different magnitudes of the ratio between the lower width and higher width (L12/L11) was investigated. It is considered water in monophase cases and water/vapor mixture for multiphase flow. Two different Reynolds numbers (ReH = 0.1 and 10.0) were investigated. Results indicated that, for the present thermal conditions, the consideration of boiling flows were not significant for prediction of optimal configurations. Results also showed that in the cases where the boiling process was enabled, the multi-objective performance was higher than in the cases without boiling, especially for ReH = 0.1.

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Section: Numerical Modelingsupporting

confidence: 77%

Section: Numerical Modelingmentioning

confidence: 99%

Geometrical investigation of microchannel with two trapezoidal blocks subjected to laminar convective flows with and without boiling

et al. 2022

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“…Volume-of-fluids (VOF) interface capturing technique (Hirt and Nichols, 1981) has been adopted to track the two-phase interface between the fluids. The model has been extensively used by several groups of researchers (Gupta et al, 2009;Gupta et al, 2013a;Vivekanand and Raju, 2015). The governing equations of the flow and volume fraction, as well as the surface tension modeling (Brackbill et al, 1992) which are solved by the solver, can be obtained from Gupta et al (2009).…”

Section: Governing Equationsmentioning

confidence: 99%

Influence of Capillary Number on the droplet Shape, Film Thickness, and Pressure Drop in a Liquid-Liquid Taylor Flow inside a Microcapillary

Vivekanand¹,

Chandrasekhar²,

Raju³

2019

Int J Math, Eng, Manag Sci

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Numerical analysis of a two-dimensional, axisymmetric, incompressible, laminar liquid-liquid Taylor flow inside a vertical circular microchannel is carried out in the present study. The focus is laid on fluid flow characteristics in the slug flow regime. Although many researchers have performed numerical and experimental studies of two-phase flows in narrow channels, their efforts seem to have been fairly successful in explaining the underlying mechanisms of fluid flow phenomena, especially for slug flow regime. Here, an attempt has been made to explore the hydrodynamics of such flows. In the present study, dodecane and Pd5 have been used as the carrier phases and water is used as the discontinuous phase. The internal diameter of the circular microchannel is 1.5 mm with its wall being insulated. The flow and volume fraction equations are solved by the finite volume approach (FVM). The volume of fluid (VOF) method has been adopted for capturing the interface. The effect of Capillary number on film thickness and interfacial pressure drop is explained. The film thickness is found to increase with Capillary number and is also found to be in a close match with the models available in the literature. The pressure drop per unit length obtained from the CFD study is compared with a standard model available in the literature. The pressure drop across the unit cell is found to be following the phenomenological model. It is observed that the pressure drop at the interface has the highest contribution to the total pressure drop in contrast to the other pressure drops in the channel, with ~50-55% in dodecane-water and ~55-62% in Pd5-water systems. Besides, the distribution of the velocity, axial, and wall pressure fields inside the microcapillary are also discussed.

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“…Mohammed et al [8] highlighted the deviations in some results in experimental and numerical results in microchannel applications using nanofluids. Vivekanand et al [9] studied the evaporation heat transfer in a rectangular microchannel. They showed that the vapor volume fraction varies substantially when the heat flux boundary condition is applied at the wall.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the Flow Characteristics of Titanium - Oxide - Water Nanofluid in Microchannel with Circular Cross Section

Etaig¹,

Hasan²,

Perera³

2017

NANO

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The presented paper reports the analysis of the flows characteristic of TiO 2-water nanofluid flowing inside a horizontal microchannel with circular cross section area. The flow is investigated by CFD techniques using a finite volume method. A recently introduced viscosity correlation was used to model the effective viscosity of the nanofluid. A range of Re number is tested in the present study. Various temperature ranges were used as constant temperature boundary conditions. The increase of the nanoparticle volume fraction was found to increase the heat transfer rate; water showed less enhancement in heat transfer compared to the nanofluid. The increase in Re number promoted Nu number. The effect of the temperature on the effective viscosity in the channel was also reported. The change of the velocity in the entrance region was studied and discussed. The velocity gradient in the microchannel is calculated, and the results are shown and discussed.

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Simulation of Evaporation Heat Transfer in a Rectangular Microchannel

Cited by 9 publications

References 10 publications

Geometrical investigation of microchannel with two trapezoidal blocks subjected to laminar convective flows with and without boiling

Geometrical investigation of microchannel with two trapezoidal blocks subjected to laminar convective flows with and without boiling

Influence of Capillary Number on the droplet Shape, Film Thickness, and Pressure Drop in a Liquid-Liquid Taylor Flow inside a Microcapillary

Investigation of the Flow Characteristics of Titanium - Oxide - Water Nanofluid in Microchannel with Circular Cross Section

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