scholarly journals Phase transition in a cell fluid model

2017 ◽  
Vol 20 (2) ◽  
pp. 23501 ◽  
Author(s):  
Kozlovskii ◽  
Dobush
Keyword(s):  
Phase Transition ◽  
Fluid Model ◽  
A Cell

scholarly journals Using a Cell Fluid Model for the Description of a Phase Transition in Simple Liquid Alkali Metals

2017 ◽  
Vol 62 (10) ◽  
pp. 865-873 ◽  
Author(s):  
M.P. Kozlovskii ◽  
◽  
O.A. Dobush ◽  
I.V. Pylyuk ◽  
◽  
...  
Keyword(s):  
Phase Transition ◽  
Alkali Metals ◽  
Fluid Model ◽  
Simple Liquid ◽  
A Cell ◽  
Liquid Alkali Metals

Numerical Analysis of Two-Phase Pipe Flow of Liquid Helium Using Multi-Fluid Model

2001 ◽  
Vol 123 (4) ◽  
pp. 811-818 ◽  
Author(s):  
Jun Ishimoto ◽  
Mamoru Oike ◽  
Kenjiro Kamijo
Keyword(s):  
Phase Transition ◽  
Gas Phase ◽  
Liquid Helium ◽  
Two Phase Flow ◽  
Fluid Model ◽  
Numerical Results ◽  
Phase Flow ◽  
Two Dimensional ◽  
Two Phase ◽  
Normal Fluid

The two-dimensional characteristics of the vapor-liquid two-phase flow of liquid helium in a pipe are numerically investigated to realize the further development and high performance of new cryogenic engineering applications. First, the governing equations of the two-phase flow of liquid helium based on the unsteady thermal nonequilibrium multi-fluid model are presented and several flow characteristics are numerically calculated, taking into account the effect of superfluidity. Based on the numerical results, the two-dimensional structure of the two-phase flow of liquid helium is shown in detail, and it is also found that the phase transition of the normal fluid to the superfluid and the generation of superfluid counterflow against normal fluid flow are conspicuous in the large gas phase volume fraction region where the liquid to gas phase change actively occurs. Furthermore, it is clarified that the mechanism of the He I to He II phase transition caused by the temperature decrease is due to the deprivation of latent heat for vaporization from the liquid phase. According to these theoretical results, the fundamental characteristics of the cryogenic two-phase flow are predicted. The numerical results obtained should contribute to the realization of advanced cryogenic industrial applications.

scholarly journals A two-fluid model for tissue growth within a dynamic flow environment

2008 ◽  
Vol 19 (6) ◽  
pp. 607-634 ◽  
Author(s):  
R. D. O'DEA ◽  
S. L. WATERS ◽  
H. M. BYRNE
Keyword(s):  
Cell Population ◽  
Culture Medium ◽  
Local Density ◽  
Fluid Model ◽  
Tissue Growth ◽  
Viscous Drag ◽  
Mechanical Environment ◽  
A Cell ◽  
Two Fluid Model ◽  
Tissue Construct

We study the growth of a tissue construct in a perfusion bioreactor, focussing on its response to the mechanical environment. The bioreactor system is modelled as a two-dimensional channel containing a tissue construct through which a flow of culture medium is driven. We employ a multiphase formulation of the type presented by G. Lemon, J. King, H. Byrne, O. Jensen and K. Shakesheff in their study (Multiphase modelling of tissue growth using the theory of mixtures.J. Math. Biol.52(2), 2006, 571–594) restricted to two interacting fluid phases, representing a cell population (and attendant extracellular matrix) and a culture medium, and employ the simplifying limit of large interphase viscous drag after S. Franks in her study (Mathematical Modelling of Tumour Growth and Stability. Ph.D. Thesis, University of Nottingham, UK, 2002) and S. Franks and J. King in their study (Interactions between a uniformly proliferating tumour and its surrounding: Uniform material properties.Math. Med. Biol.20, 2003, 47–89).The novel aspects of this study are: (i) the investigation of the effect of an imposed flow on the growth of the tissue construct, and (ii) the inclusion of a mechanotransduction mechanism regulating the response of the cells to the local mechanical environment. Specifically, we consider the response of the cells to their local density and the culture medium pressure. As such, this study forms the first step towards a general multiphase formulation that incorporates the effect of mechanotransduction on the growth and morphology of a tissue construct.The model is analysed using analytic and numerical techniques, the results of which illustrate the potential use of the model to predict the dominant regulatory stimuli in a cell population.

scholarly journals Continuous phase transition and microstructure of charged AdS black hole with quintessence

2020 ◽  
Vol 80 (2) ◽  
Author(s):  
Xiong-Ying Guo ◽  
Huai-Fan Li ◽  
Li-Chun Zhang ◽  
Ren Zhao
Keyword(s):  
Phase Transition ◽  
Black Holes ◽  
Black Hole ◽  
Fluid Model ◽  
Critical Phenomenon ◽  
Continuous Phase ◽  
Continuous Phase Transition ◽  
Small Black Hole ◽  
Ads Black Holes ◽  
Quintessence Field

Abstract Previously, the Maxwell equal-area law has been used to discuss the conditions satisfied by the phase transition of charged AdS black holes with cloud of string and quintessence, and it was concluded that black holes have phase transition similar to that of vdW system. The phase transition depends on the electric potential of the black hole and is not the one between a large black hole and a small black hole. On the basis of this result, we study the relation between the latent heat of the phase transition and the parameter of dark energy, and use the Landau continuous phase transition theory to discuss the critical phenomenon of the black hole with quintessence and give the critical exponent. By introducing the number density of the black hole molecules, some properties of the microstructure of black holes are studied in terms of a phase transition. It is found that the electric charge of the black hole and the normalization parameter related to the density of quintessence field play a key role in the phase transition. By constructing the binary fluid model of the black hole molecules, we also discuss the microstructure of charged AdS black holes with a cloud of strings and quintessence.

scholarly journals Phase Transition in Ferromagnetic Ising Model with a Cell-Board External Field

2015 ◽  
Vol 162 (1) ◽  
pp. 139-161
Author(s):  
Manuel González-Navarrete ◽  
Eugene Pechersky ◽  
Anatoly Yambartsev
Keyword(s):  
Phase Transition ◽  
Ising Model ◽  
External Field ◽  
A Cell ◽  
Ferromagnetic Ising Model

On Treatment of Negative Pressures in Fluid Dynamics

2005 ◽  
Author(s):  
Iztok Tiselj ◽  
Janez Gale
Keyword(s):  
Fluid Dynamics ◽  
Phase Transition ◽  
Two Phase Flow ◽  
Fluid Model ◽  
Saturation Pressure ◽  
Phase Flow ◽  
Two Phase ◽  
Negative Pressures ◽  
Two Fluid Model ◽  
Two Fluid

Rapid depressurization of a cold single-phase liquid leads to the onset of a vaporisation, i.e. the phase transition phenomena. Prior to the start and in the very first moment of the phase transition, pressure in the liquid may briefly drop to negative values, when initial liquid temperature is low enough. Metastable liquid in a state of tension is well known in static experiments, but is less known in the fluid dynamics. The present paper discusses some preliminary findings in the field of modeling of the negative pressures in transient water flows and subsequent phase transition with a single-pressure two-fluid model. A highly simplified single-pressure two-fluid model is used in the present work to describe the two-phase flow with negative liquid and positive vapor pressure. The assumption used at negative liquid pressures is equal temperature of liquid and newly generated vapor phase, while the gas pressure is assumed to be the saturation pressure at that temperature. Rather rough models seem to be sufficiently accurate due to the large uncertainty in the modeling of the single-to-two-phase flow transition, which strongly depends on the density of the nucleation sites in the liquid and at the wall.

scholarly journals Equation of State of a Cell Fluid Model with Allowance for Gaussian Fluctuations of the Order Parameter

2020 ◽  
Vol 65 (12) ◽  
pp. 1080
Author(s):  
I.V. Pylyuk ◽  
O.A. Dobush
Keyword(s):  
Equation Of State ◽  
Order Parameter ◽  
Chemical Potential ◽  
Fluid Model ◽  
Repulsive Interaction ◽  
Collective Variables ◽  
Relative Temperature ◽  
A Cell ◽  
Supercritical Temperature

The paper is devoted to the development of a microscopic description of the critical behavior of a cell fluid model with allowance for the contributions from collective variables with nonzero values of the wave vector. The mathematical description is performed in the supercritical temperature range (T > Tc) in the case of a modified Morse potential with additional repulsive interaction. The method, developed here for constructing the equation of state of the system by using the Gaussian distribution of the order parameter fluctuations, is valid beyond an immediate vicinity of the critical point for wide ranges of the density and temperature. The pressure of the system as a function of the chemical potential and density is plotted for various fixed values of the relative temperature, both with and without considering the above-mentioned contributions. Compared with the results of the zero-mode approximation, the insignificant role of these contributions is indicated for temperatures T > Tc. At T < Tc, they are more significant.

scholarly journals Phase Behavior of a Cell Fluid Model with Modified Morse Potential

2020 ◽  
Vol 65 (5) ◽  
pp. 428
Author(s):  
M. P. Kozlovskii ◽  
O. A. Dobush
Keyword(s):  
Phase Transition ◽  
Morse Potential ◽  
Chemical Potential ◽  
Fluid Model ◽  
Potential Temperature ◽  
Theoretical Description ◽  
Repulsive Interaction ◽  
Limited Temperature ◽  
Wide Range ◽  
Limited Temperature Range

The present article gives a theoretical description of a first-order phase transition in the cell fluid model with a modified Morse potential and an additional repulsive interaction. In the framework of the grand canonical ensemble, the equation of state of the system in terms of chemical potential–temperature and terms of density–temperature is calculated for a wide range of the density and temperature. The behavior of the chemical potential as a function of the temperature and density is investigated. The maximum and minimum admissible values of the chemical potential, which approach each other with decreasing the temperature, are exhibited. The existence of a liquid-gas phase transition in a limited temperature range below the critical Tc is established.

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