Numerical Computation of Phase Separation in Two Fluid Flow

1984 ◽  
Vol 106 (2) ◽  
pp. 147-153 ◽  
Author(s):  
M. B. Carver
Keyword(s):  
Experimental Study ◽  
Fluid Flow ◽  
Phase Separation ◽  
Numerical Computation ◽  
Computational Analysis ◽  
Fluid Flows ◽  
Iterative Approach ◽  
Two Fluid

A new iterative approach is outlined for multidimensional computational analysis of two fluid flow. Parametric surveys are described to illustrate that the method rationally predicts separation of two fluid flows under gravitational and centrifugal influences. A comparison is made between behavior computed by the method, and results reported in an experimental study of air and water flowing in elbows and pipes.

A Method of Limiting Intermediate Values of Volume Fraction in Iterative Two-Fluid Computations

1982 ◽  
Vol 24 (4) ◽  
pp. 221-224 ◽  
Author(s):  
M. B. Carver
Keyword(s):  
Fluid Flow ◽  
Computational Analysis ◽  
Volume Fraction ◽  
Simultaneous Solution ◽  
Two Phase ◽  
Upper Limit ◽  
Satisfactory Method ◽  
Iterative Procedures ◽  
Physical Reasons ◽  
Two Fluid

Multidimensional computational analysis of fluid flow is usually done by segmented iterative methods, as the equations sets generated are too large to permit simultaneous solution. Frequently the need arises to compute values for variables which must remain bounded for physical reasons. In two-phase computation, for example, the volume fraction is restricted to values between 0 and 1, but iterative procedures often return intermediate values which violate these bounds. It is fairly straightforward to prevent negative values, however no satisfactory method of imposing the upper limit has been published. A method of smoothly applying the limit in reversible fashion is outlined in this note.

Lattice-BGK Methods for Simulating Incompressible Fluid Flows

1997 ◽  
Vol 08 (04) ◽  
pp. 793-803 ◽  
Author(s):  
Yu Chen ◽  
Hirotada Ohashi
Keyword(s):  
Fluid Flow ◽  
Incompressible Fluid ◽  
Poisson Equation ◽  
General Model ◽  
Incompressible Flows ◽  
Fluid Flows ◽  
Incompressible Limit ◽  
Numerical Example ◽  
Incompressible Fluid Flows

The lattice-Bhatnagar-Gross-Krook (BGK) method has been used to simulate fluid flow in the nearly incompressible limit. But for the completely incompressible flows, two special approaches should be applied to the general model, for the steady and unsteady cases, respectively. Introduced by Zou et al.,1 the method for steady incompressible flows will be described briefly in this paper. For the unsteady case, we will show, using a simple numerical example, the need to solve a Poisson equation for pressure.

Experimental study of phase separation in films of molecular dimensions

1989 ◽  
Vol 39 (16) ◽  
pp. 11750-11754 ◽  
Author(s):  
Hugo K. Christenson ◽  
Jiafu Fang ◽  
Jacob N. Israelachvili
Keyword(s):  
Experimental Study ◽  
Phase Separation ◽  
Molecular Dimensions

scholarly journals Control of vortex breakdown in confined two-fluid flows

2020 ◽  
Vol 1675 ◽  
pp. 012015
Author(s):  
I V Naumov ◽  
B R Sharifullin ◽  
V N Shtern
Keyword(s):  
Vortex Breakdown ◽  
Fluid Flows ◽  
Two Fluid

A Suction Device Using Air Under Pressure

1956 ◽  
Vol 23 (2) ◽  
pp. 269-272
Author(s):  
L. F. Welanetz
Keyword(s):  
Fluid Flow ◽  
Flow Rate ◽  
Fluid Flows ◽  
Central Hole ◽  
Fluid Flow Rate ◽  
Circular Plates ◽  
Suction Device ◽  
Holding Power ◽  
Plate Separation

Abstract An analysis is made of the suction holding power of a device in which a fluid flows radially outward from a central hole between two parallel circular plates. The holding power and the fluid flow rate are determined as functions of the plate separation. The effect of changing the proportions of the device is investigated. Experiments were made to check the analysis.

Unstable Two-Fluid Flow in a Porous Medium

1969 ◽  
Vol 9 (03) ◽  
pp. 293-300 ◽  
Author(s):  
J.E. Varnon ◽  
R.A. Greenkorn
Keyword(s):  
Porous Medium ◽  
Fluid Flow ◽  
Flow Regime ◽  
Flow Regimes ◽  
Gravity Force ◽  
Unstable Flow ◽  
Stable Regime ◽  
Viscous Forces ◽  
Finger Width ◽  
Two Fluid

Abstract This paper reports an investigation of unstable fingering in two-fluid flow in a porous medium to determine if lambda the dimensionless finger width, is unique For a viscous finger A is the ratio of finger width to the distance between the tips of the two trailing fingers adjacent to the leading finger. For a gravity finger lambda is defined as the ratio of finger width, to "height" of the medium perpendicular to hulk flow. This work confirms previous experiments and existing theory that for viscous fingering lambda approaches a value of 0.5 with increasing ratio of viscous to interfacial force. However, for a given fluid pair and given, medium, this ratio can he increased only by increasing the, velocity. Experiments on gas liquid systems show that the asymptotic value of lambda with velocity is not always 0.5. Apparently, for gas-liquid systems, the influence of the interfacial force cannot always he eliminated by increasing the velocity. For such systems lambda is a function of fluid pair and media permeability. If the gravity force normal to the hulk permeability. If the gravity force normal to the hulk flow is active, it damps out the viscous fingers except for an underlying or overlying finger. The dimensionless width of this gravity finger strongly depends on velocity and height of the medium, as well as the fluid and media properties. The existing experiments and theories are reviewed and the gravity, stable, and viscous flow regimes are described in view of these experiments and theories. The existence of a gravity-dominated unstable regime, a gravity-viscous balanced stable regime, and a viscous-anminated regime was demonstrated experimentally by increasing flow velocity bin a rectangular glass head model. Asymptotic values of the dimensionless finger width were determined in various-sized Hele-Shaw models with gravity perpendicular and parallel to flow. The dimensionless perpendicular and parallel to flow. The dimensionless finger width lambda was determined as a function of applied force, flow resistance, and fluid properties. The results are interpreted dimensionally. Some comments are made concerning possible scaling and meaningful extensions of theory to describe these regimes in three-dimensional flow. Previous description of unstable two-fluid flow in porous media is mainly restricted to studies of viscous-dominated instability. The direction of this study is to provide data and understanding to consider the more realistic problem of predicting flow in three dimensions that may result in instabilities that are combinations of all, four flow regimes. Introduction The unstable flow of two fluids is characterized by interface changes between the fluids as a result of changes in relative forces. In a given porous medium and for a given fluid pair the gravity force dominates flow at low displacement velocities. As the velocity increases the viscous forces begin to affect flow significantly, and eventually there is a balance between effects of the gravity and viscous forces. As velocity increases further, the viscous force dominates flow. In the plane parallel to gravity, four flow regimes result as the velocity is increased: a gravity-induced stable flow regime; a gravity-dominated unstable flow regime; a stable regime resulting from a balance between gravity and viscous forces; and a viscous-induced unstable flow regime. The gravity-induced stable regime is represented schematically in Fig. 1a. This general flow pattern persists with the displacing fluid contacting all of persists with the displacing fluid contacting all of the in-place fluid until the interface becomes parallel to the bulk flow. At this velocity a gravity finger forms, and the interface, is unstable in that the length of the gravity finger grows and the fluid behind the nose of the finger is practically nonmobile because of the small pressure gradient along the finger. The gravity-dominated unstable flow is shown schematically in Fig. 1b. As the injection rate is increased, the gravity finger thickens, perhaps until it spans the medium creating a stable interface where all of the in-place, fluid is again mobile. This regime would, not occur in the absence of gravity. It occurs due to the counter effects of the gravity and viscous forces (Fig. 1c). As the velocity of the displacing fluid increases, the viscous forces dominate, and, the interface breaks into viscous fingers (Fig. 1d). SPEJ p. 293

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