Boundary Layer Mechanism of a Two-Phase Nanofluid Subject to Coupled Interface Dynamics of Fluid/Film

AbstractThis article investigates boundary layer mechanism of a two-phase nanofluid over a thin liquid film of power-law fluid. We take the coupled interface dynamics between the thin liquid film and nanofluid into consideration, where the thermal conductivity and dynamic viscosity are assumed to be linear functions of nanoparticle concentration. The influence of Brownian motion and thermophoresis of the nanofluid is also considered. Numerical results are carried out by employing similarity transformation and bvp4c technique. The heat and mass transfer in the flow boundary layer are analysed by relevant parameters with the assistance of graphs. The results show that heat conduction decreases significantly with the increase of rheological properties parameter and tensile velocity ratio. Rheological properties parameter, tensile velocity ratio, Brownian motion parameter and thermophoresis parameter play important roles in mass transfer.

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Analysis of unsteady magnetohydrodynamic radiative thin liquid film flow, heat and mass transfer over a stretching sheet with variable viscosity and thermal conductivity

International Journal for Computational Methods in Engineering Science and Mechanics ◽

10.1080/15502287.2021.1887406 ◽

2021 ◽

pp. 1-10

Author(s):

Dulal Pal ◽

Prasenjit Saha

Keyword(s):

Thermal Conductivity ◽

Mass Transfer ◽

Liquid Film ◽

Heat And Mass Transfer ◽

Stretching Sheet ◽

Film Flow ◽

Variable Viscosity ◽

Thin Liquid Film ◽

Liquid Film Flow ◽

Flow Heat

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Measurement of Liquid Film Thickness for Annular Two-Phase HFC134a Gas-Liquid Ethanol Flow in the Vertical Tube

10.1115/icone28-63488 ◽

2021 ◽

Author(s):

Huacheng Zhang ◽

Tutomo Hisano ◽

Shoji Mori ◽

Hiroyuki Yoshida

Keyword(s):

Film Thickness ◽

Liquid Film ◽

Thin Liquid Film ◽

Atmospheric Condition ◽

Heating Surface ◽

Operating Conditions ◽

Liquid Film Thickness ◽

Two Phase ◽

Disturbance Waves ◽

Analytical Approaches

Abstract Annular gas-liquid two-phase flows, such as the flows attached to the fuel rods of boiling water reactors (BWR), are a prevalent occurrence in industrial processes. At the gas-liquid interface of such flows, disturbance waves with diverse velocity and amplitude commonly arise. Since the thin liquid film between two successive disturbance waves leads to the dryout on the heating surface and limits the performance of the BWRs, complete knowledge of the disturbance waves is of great importance for the characterized properties of disturbance waves. The properties of disturbance waves have been studied by numerous researchers through extensive experimental and analytical approaches. However, most of the experimental data and analyses available in the literature are limited to the near atmospheric condition. In consideration of the properties of liquids and gases under atmospheric pressure which are distinct from those under BWR operating conditions (7 MPa, 285 °C), we employed the HFC134a gas and liquid ethanol whose properties at relatively low pressure and temperature (0.7 MPa, 40 °C) are similar to those of steam and water under BWR operating conditions as working fluids in a tubular test section having an inside diameter 5.0mm. Meanwhile, the liquid film thickness is measured by conductance probes. In this study, we report the liquid film thickness characteristics in a two-phase HFC134a gas-liquid ethanol flow. A simple model of the height of a disturbance wave was also proposed.

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Lyon-Type Integral Forms of Wall Friction, Heat- and Mass Transfer Closure Relationships for Non-Equilibrium Two-Phase Flows: Generalization for Annular and Rod Cluster Geometries

Volume 8C: Heat Transfer and Thermal Engineering ◽

10.1115/imece2013-66044 ◽

2013 ◽

Author(s):

Yuri Kornienko

Keyword(s):

Boundary Layer ◽

Mass Transfer ◽

Heat And Mass Transfer ◽

Constitutive Relations ◽

Wall Friction ◽

Transfer Coefficients ◽

Two Phase ◽

Friction Heat ◽

Integral Forms ◽

Substance Transfer

The main goal of this paper is to describe new approach to constructing generalized closure relationships for pipe, annular and sub-channel transfer coefficients for wall friction, heat and mass transfer. The novelty of this approach is that it takes into account not only axial and transversal parameter distributions, but also an azimuthal substance transfer effects. These constitutive relations, which are primordial in the description of single- and two-phase one-dimensional (1D) flow models, can be derived from the initial 3D drift flux formulation. The approach is based on the Reynolds flow, boundary layer, and substance transfer generalized coefficient concepts. Another aim is to illustrate the validity of the “conformity principle” for the limiting cases. The method proposed in this paper is founded on the similarity theory, boundary layer model, and a phenomenological description of the regularity of the substance transfer (momentum, heat, and mass) as well as on an adequate simulation of the flow structures. With the proposed generalized approach it becomes possible to develop an integrated in form and semi-empirical in maintenance structure analytical relationships for wall friction, heat and mass transfer coefficients.

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Nonlinear thermal radiation and temperature dependent viscosity effects on MHD heat and mass transfer in a thin liquid film over a stretching surface

Journal of Mathematical and Computational Science ◽

10.28919/jmcs/6785 ◽

2021 ◽

Keyword(s):

Mass Transfer ◽

Thermal Radiation ◽

Liquid Film ◽

Thin Liquid Film ◽

Nonlinear Thermal Radiation ◽

Stretching Surface ◽

Temperature Dependent ◽

Temperature Dependent Viscosity ◽

Viscosity Effects ◽

Dependent Viscosity

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Corrigendum to “Influence of the aligned flow obstacles on critical heat flux in two-phase boundary layer flow under a low flow condition” [Int. J. Heat Mass Transfer 121 (2018) 1234–1250]

International Journal of Heat and Mass Transfer ◽

10.1016/j.ijheatmasstransfer.2018.04.029 ◽

2018 ◽

Vol 124 ◽

pp. 884

Author(s):

Uiju Jeong ◽

Hong Hyun Son ◽

Sung Joong Kim

Keyword(s):

Boundary Layer ◽

Mass Transfer ◽

Heat Flux ◽

Phase Boundary ◽

Boundary Layer Flow ◽

Flow Condition ◽

Heat Mass Transfer ◽

Low Flow ◽

Two Phase ◽

Layer Flow

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ANALYSIS OF INTERFACIAL AND MASS TRANSFER EFFECTS ON FORCED CONVECTION IN GAS-LIQUID ANNULAR TWO-PHASE FLOW

Revista de Engenharia Térmica ◽

10.5380/reterm.v3i1.3483 ◽

2004 ◽

Vol 3 (1) ◽

pp. 45

Author(s):

E. Nogueira ◽

B. D. Dantas ◽

R. M. Cotta

Keyword(s):

Heat Transfer ◽

Mass Transfer ◽

Film Thickness ◽

Liquid Film ◽

Liquid Film Thickness ◽

Phase Flow ◽

Transfer Effects ◽

Two Phase ◽

Transfer Rates ◽

Interface Waves

In a gas-liquid annular two-phase flow one of the main factors influencing the determination of heat transfer rates is the average thickness of the liquid film. A model to accurately represent the heat transfer in such situations has to be able of determining the average liquid film thickness to within a reasonable accuracy. A typical physical aspect in gas-liquid annular flows is the appearance of interface waves, which affect heat, mass and momentum transfers. Existing models implicitly consider the wave effects in the momentum transfer by an empirical correlation for the interfacial friction factor. However, this procedure does not point out the difference between interface waves and the natural turbulent effects of the system. In the present work, the wave and mass transfer effects in the theoretical estimation of average liquid film thickness are analyzed, in comparison to a model that does not explicitly include these effects, as applied to the prediction of heat transfer rates in a thermally developing flow situation.

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Numerical Simulation of Evaporating Two-Phase Flow in a High-Aspect-Ratio Microchannel with Bends

Journal of Heat Transfer ◽

10.1115/1.4035571 ◽

2017 ◽

Vol 139 (2) ◽

Cited By ~ 3

Author(s):

Zhenhai Pan ◽

Justin A. Weibel ◽

Suresh V. Garimella

Keyword(s):

Aspect Ratio ◽

Liquid Film ◽

High Aspect Ratio ◽

Two Phase Flow ◽

Flow Boiling ◽

Fluid Velocity ◽

Thin Liquid Film ◽

Heated Wall ◽

Phase Flow ◽

Two Phase

Despite the demand for high-performance, two-phase cooling systems, high-fidelity simulations of flow boiling in complex microchannel geometries remains a challenging numerical problem. We conduct a first-principles-based simulation of an evaporating two-phase flow in a high-aspect-ratio microchannel with bends using a volume of fluid-based numerical model. For the case shown, the lower horizontal section of the microchannel has a constant flux of 20 W/cm2 applied to the wetted wall area (heat flux at the base of 133 W/cm2); HFE-7100 vapor and liquid enter the channel at 2 m/s. The three-dimensional channel geometry requires a refined near-wall numerical mesh to resolve thin liquid film flow features. The recently developed saturated-interface-volume phase change model (Int J Heat Mass Trans 93:945-956, 2016) is implemented for prediction of mass and energy exchange across the liquid-vapor interface at a low computational cost (~80 hr; 6-core parallelization on Intel Xeon E3-1245V3). The model reveals transport details including the interface shape and fluid velocity and temperature fields. The interfacial temperature remains fixed at saturation with smooth velocity contours near the interface. The highest evaporation flux is located in the thin liquid film region near the heated wall.

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