Analysis of the Role of Phase Transformations in the Reproduction of Gas–Liquid Flows is a Possibility to Improve the Standards of Discharge for Multiphase Flows

2018 ◽  
Vol 60 (11) ◽  
pp. 1122-1129
Author(s):  
M. I. Tonkonog ◽  
K. A. Levin ◽  
A. S. Shabalin ◽  
V. A. Makarov ◽  
I. I. Fishman
Keyword(s):  
Phase Transformations ◽  
Multiphase Flows ◽  
Liquid Flows

scholarly journals Internal melt figures in ice by rapid adiabatic compression

1994 ◽  
Vol 40 (134) ◽  
pp. 132-134
Author(s):  
R.E. Gagnon ◽  
C. Tulk ◽  
H. Kiefte
Keyword(s):  
Phase Transformations ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Adiabatic Compression ◽  
Air Bubbles ◽  
Water Ice ◽  
Deep Focus ◽  
And Behavior ◽  
First Time

AbstractSingle crystals and bicrystals of water ice have been adiabatically pressurized to produce, and clearly illustrate, two types of internal melt figures: (1) dendritic figures that grow from nucleation imperfections on the specimen’s surface, or from air bubbles at grain boundaries, into the ice as pressure is elevated; and (2) compression melt fractures, flat liquid-filled disks, that nucleate at imperfections in the crystal and grow with the application of pressure eventually to sprout dendritic fingers at the periphery. The transparency of the ice permitted visualization of the growth and behavior of the figures, and this could be an important tool in understanding the role of phase transformations in deep-focus earthquakes. Correlation between figure size and pressure is noted for the first time.

Elemental Interfaces and Displacive Phase Transformations

2008 ◽  
Vol 59 ◽  
pp. 63-68
Author(s):  
Václav Paidar
Keyword(s):  
Phase Transformations ◽  
Structural Changes ◽  
Atomic Plane ◽  
Many Body ◽  
Single Plane ◽  
Atomistic Models ◽  
Shear Type ◽  
Hcp Structure ◽  
The Many

Two basic processes, namely shear and shuffling of atomic planes can be considered as elementary mechanisms of displacive phase transformations. The atomistic models suitable to investigate the role of interfaces in the structural changes are tested. The many-body potentials are used for the description of interatomic forces. General displacements of atomic planes are examined, i.e. γ-surface type calculations extensively used for stacking fault and lattice dislocation analysis are applied to single plane shuffling and alternate shuffling of every other atomic plane producing in combination with homogeneous deformation the hcp structure. Similar approach considering shear type planar displacements leads to the Zener path between the bcc and fcc lattices. The effect of additional deformation required to obtain the close-packed atomic arrangements is analysed.

Gas-Liquid Flows in Flow Cells and Fracture Models

2008 ◽  
Author(s):  
G. Ahmadi ◽  
D. Crandall ◽  
D. H. Smith
Keyword(s):  
Multiphase Flows ◽  
Fractured Rock ◽  
Fractal Dimensions ◽  
Flow Cell ◽  
Immiscible Fluids ◽  
Laboratory Scale ◽  
Scale Model ◽  
Computational Domain ◽  
Computational Results ◽  
Liquid Flows

Gas-liquid multiphase flows in porous media and fractured rock is of importance when carbon-dioxide displaces brine within geological reservoirs during CO2 sequestration activities. In this paper, experimental and computational modeling of multiphase flows in a porous flow cell and a modeled fracture are described. The experiments performed with the laboratory-scale flow models are described in detail. Experimental data concerning the displacement of two immiscible fluids in the lattice-like flow cell are presented. The flow pattern and the residual saturation of the displaced fluid during the displacement are discussed. It was shown that the gas-liquid flows generate fractal interfaces, with lower fractal dimensions and higher residual saturations at low injection rates. This phenomenon corresponds to viscous and capillary fingering, and is discussed. Numerical simulations of the experimental flow cell are also presented. These are shown to be similar to the experimental results, and then varied to included different surface-fluid interactions not easily studied with the experimental equipment. Numerical simulation results for single and multiphase flows through rock fractures are also presented. A fracture geometry was obtained from a series of CT scans of fractured sandstone and used to construct a laboratory scale model and a computational domain. Computational results showed that the major losses occur in the regions with smallest apertures. These computational results are compared to flows through the experimental model. An empirical expression for the fracture friction factor was also described.

Displacive Phase Transformations

2009 ◽  
Vol 150 ◽  
pp. 159-174 ◽  
Author(s):  
Václav Paidar ◽  
Andriy Ostapovets
Keyword(s):  
Phase Transformations ◽  
Atomic Plane ◽  
Many Body ◽  
Surface Type ◽  
Single Plane ◽  
Bcc Structure ◽  
Shear Type ◽  
Structural Configurations ◽  
Hcp Structure

Shear deformation and shuffling of atomic planes are elementary mechanisms of collective atomic motion that take place during displacive phase transformations. General displacements of atomic planes are examined, i.e. -surface type calculations extensively used for the stacking faults and crystal dislocations are applied to single plane shuffling and alternate shuffling of every other atomic plane producing in combination with homogeneous deformation the hcp structure (martensitic type) from the initial bcc structure (austenitic type). Similar approach considering shear type planar displacements leads to the Zener path between the bcc and fcc lattices. The effect of additional deformation required to obtain the close-packed atomic arrangements is examined as well. Finally, the influence of volume modification on phase transitions is investigated. The energies of various structural configurations are calculated using many-body potentials for the description of interatomic forces. Such atomic models are tested to check their suitability for investigation of the role of interfaces in the displacive structural transitions.

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