Pipe Flow Models | ScienceGate

One-dimensional (1D), equilibrium-based mechanistic model predictions are compared to three-dimensional (3D) transient computational fluid dynamics results for horizontal two-phase, gas-liquid pipe flow. The 3D regions of interest include both those expected to be in equilibrium conditions and those where transitions between flow regimes occur. Equilibrium simulations, such as those for stratified flow in a horizontal pipe, allow crucial validation of the equilibrium-based closure relations by means of numerical experiments. In the transitional regions, fully 3D, time-dependent numerical simulations provide a means to estimate the error in the equilibrium-based models and suggest how reasonable approximations can be made in these regions.

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Maximum Two-Phase Vessel Blowdown From Pipes

Journal of Heat Transfer ◽

10.1115/1.3691539 ◽

1966 ◽

Vol 88 (3) ◽

pp. 285-294 ◽

Cited By ~ 44

Author(s):

F. J. Moody

Keyword(s):

Pipe Flow ◽

Reasonable Agreement ◽

Water Flow Rate ◽

Water Systems ◽

Phase Flow ◽

Two Phase ◽

Flow Rates ◽

Flow Models ◽

Saturated Water ◽

Constant Area

Existing flow models are applied to predict maximum two-phase flow from a constant area, adiabatic pipe with friction. Graphs are given for maximum steam/water flow rate in terms of pipe f(L/D) and entrance stagnation properties. Theoretical blow-downs are graphed for 1000 and 2000 psia saturated-water systems with f(L/D) ranging from 0.0 to 100. Estimated pipe flow rates and blowdown transients are compared with steam/water data. Reasonable agreement is shown.

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Two-phase flow in smooth and rough fractures: Measurement and correlation by porous-medium and pipe flow models

Water Resources Research ◽

10.1029/93wr01529 ◽

1993 ◽

Vol 29 (11) ◽

pp. 3699-3708 ◽

Cited By ~ 87

Author(s):

M. Fourar ◽

S. Bories ◽

R. Lenormand ◽

P. Persoff

Keyword(s):

Porous Medium ◽

Pipe Flow ◽

Two Phase Flow ◽

Phase Flow ◽

Two Phase ◽

Flow Models

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Avalanche Stratification - Experimental Tests of the “Metastable Wedge” and “Continuous Flow” Models

MRS Proceedings ◽

10.1557/proc-627-bb2.6 ◽

2000 ◽

Vol 627 ◽

Author(s):

M. E. Swanson ◽

M. Landreman ◽

J. Michel ◽

J. Kakalios

Keyword(s):

Continuous Flow ◽

Granular Media ◽

Experimental Tests ◽

Coarse Sand ◽

Angle Of Repose ◽

Flow Models ◽

Maximum Angle ◽

Stratification Effect ◽

Upward Moving ◽

Moving Layer

ABSTRACTWhen an initially homogeneous binary mixture of granular media such as fine and coarse sand is poured near the closed edge of a “quasi-two-dimensional” Hele-Shaw cell consisting of two vertical transparent plates held a narrow distance apart, the mixture spontaneously forms alternating segregated layers. Experimental measurements of this stratification effect are reported in order to determine which model, one which suggests that segregation only occurs when the granular material contained within a metastable heap between the critical and maximum angle of repose avalanches down the free surface, or one for which the segregation results from smaller particles becoming trapped in the top surface and being removed from the moving layer during continuous flow. The result reported here indicate that the Metastable Wedge model provides a natural explanation for the initial mixed zone which precedes the formation of the layers, while the Continuous Flow model explains the observed upward moving kink of segregated material for higher granular flux rates, and that both mechansims are necessary in order to understand the observed pairing of segregated layersfor intermediate flow rates and cell separations.

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