A hydrodynamic model for two-phase flow through porous media

Tung, V.X.; Dhir, Vijay K.

doi:10.1016/0301-9322(88)90033-x

Cited by 142 publications

(84 citation statements)

References 6 publications

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“…Two-phase flow in porous media is generally classified into countercurrent and crosscurrent flow arrangements [90]. Simplified modeling and empirical correlation of two-phase pressure drop is limited to these arrangements [91][92][93][94]. Further, pressure drop is highly dependent on the flow regime, and mechanistic predictions cannot be formulated without extensive visualization of the interstitial vapor phase.…”

Section: Dryout Mechanisms and Heater Size Dependencymentioning

confidence: 99%

Recent Advances in Vapor Chamber Transport Characterization for High-Heat-Flux Applications

Weibel

Garimella

2013

Advances in Heat Transfer

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Owing to their high reliability, simplicity of manufacture, passive operation, and effective heat transport, flat heat pipes and vapor chambers are used extensively in the thermal management of electronic devices. The need for concurrent size, weight, and performance improvements in high-performance electronics systems, without resort to active liquid-cooling strategies, demands passive heat spreading technologies that can dissipate extremely high heat fluxes from small hot spots. In response to these daunting application-driven trends, a number of recent investigations have focused on the design, characterization, and fabrication of ultra-thin vapor chambers for proximate heat spreading away from these hot spots. The predominant transport mechanisms and operational limits have been found to be different under these conditions relative to conventional low-power heat pipes. Noteworthy advances in the fundamental understanding of evaporation and boiling from porous microstructures fed by capillary action, and improvements in vapor chamber characterization, modeling, design, and fabrication techniques are reviewed. Characterization of evaporation and boiling from idealized and realistic wick structures, observation of vapor formation regimes as a function of operating conditions, assessment of fluid dryout limitations, design of novel multi-scale and nanostructured wicks for enhanced transport, and incorporation of these high heat flux transport phenomena into device-level models are discussed. These recent developments have successfully extended the maximum operating heat flux limits of vapor chambers.2

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Section: Dryout Mechanisms and Heater Size Dependencymentioning

confidence: 99%

Recent Advances in Vapor Chamber Transport Characterization for High-Heat-Flux Applications

Weibel

Garimella

2013

Advances in Heat Transfer

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“…The boundaries between flow regimes are as defined by Tung. 12 While the physical basis for these boundaries is not well-established, the presentation of a more thorough physical basis is beyond the scope of this work. The void fraction at which the flow regime changes from inverted slug-mist flow to mist flow is assumed to be 0.925.…”

Section: Interface Of Relap5 and Couple And Assumptions In Modelingmentioning

confidence: 99%

“…It can also be shown that and should be (3)(4)(5)(6)(7)(8)(9)(10)(11) and (3)(4)(5)(6)(7)(8)(9)(10)(11)(12) where…”

Section: Energy Conservationmentioning

confidence: 99%

“…The total heat transfer to the vapor is then (5)(6)(7)(8)(9)(10)(11)(12) where Q = total heat transfer to vapor (W/m 3 ).…”

Section: Symbol Units Definitionmentioning

confidence: 99%

“…The heat transfer correlation developed by Tung 12 will be used to calculate the debris-to-vapor convective heat transfer. In this correlation, the Nusselt number is given by the equation For the case of low fluid velocity, the Nusselt number for natural convection will also be calculated.…”

Section: Single Phase Vapor Regimementioning

confidence: 99%

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SCDAP/RELAP5 modeling of heat transfer and flow losses in lower head porous debris. Revision 1

Siefken¹,

Coryell²,

Paik³

et al. 1999

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Designs are described for implementing models for calculating the heat transfer and flow losses in porous debris in the lower head of a reactor vessel. The COUPLE model in SCDAP/RELAP5 represents both the porous and nonporous debris that results from core material slumping into the lower head. Currently, the COUPLE model has the capability to model convective and radiative heat transfer from the surfaces of nonporous debris in a detailed manner and to model only in a simplistic manner the heat transfer from porous debris. In order to advance beyond the simplistic modeling for porous debris, designs are developed for detailed calculations of heat transfer and flow losses in porous debris. Correlations are identified for convective heat transfer in porous debris for the following modes of heat transfer; (1) forced convection to liquid, (2) forced convection to gas, (3) nucleate boiling, (4) transition boiling, and (5) film boiling. Interphase heat transfer is modeled in an approximate manner. Designs are described for models to calculate the flow losses and interphase drag of fluid flowing through the interstices of the porous debris, and to apply these variables in the momentum equations in the RELAP5 part of the code. Since the models for heat transfer and flow losses in porous debris in the lower head are designed for general application, a design is also described for implementation of these models to the analysis of porous debris in the core region. A test matrix is proposed for assessing the capability of the implemented models to calculate the heat transfer and flow losses in porous debris. The implementation of the models described in this report is expected to improve the COUPLE code calculation of the temperature distribution in porous debris and in the lower head that supports the debris. The implementation of these models is also expected to improve the calculation of the temperature and flow distribution in porous debris in the core region.vi

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Two-Phase Frictional Pressure Drop in Flooded-Bed Reactors: A State-of-the-art Correlation

Larachi¹,

Bensetiti

Grandjean

et al. 1998

Chem. Eng. Technol.

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A state-of-the-art correlation for the prediction of frictional gas-liquid pressure drop in cocurrent upflow fixed bed reactors was derived based on a wide hydrodynamic data bank of flooded packed-bed reactors. The data bank, which contains more than 3400 measurements, was constructed using information collected from 22 sources over the past 40 years. The correlation, which relied upon combination of dimensional analysis and artificial feed-forward neural networks, was expressed as a two-phase friction factor function of the five most pertinent dimensionless groups (Re LG , Mo, St, Fr L , X L ). The prediction and generalization capabilities of the proposed correlation and the limits of existing literature correlations and models were demonstrated by systematic statistical tests over the constructed data bank.

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A hydrodynamic model for two-phase flow through porous media

Cited by 142 publications

References 6 publications

Recent Advances in Vapor Chamber Transport Characterization for High-Heat-Flux Applications

Recent Advances in Vapor Chamber Transport Characterization for High-Heat-Flux Applications

SCDAP/RELAP5 modeling of heat transfer and flow losses in lower head porous debris. Revision 1

Two-Phase Frictional Pressure Drop in Flooded-Bed Reactors: A State-of-the-art Correlation

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