Multiphase Flows Through Poro-Elastic Media: A Continuum Model

2002 ◽  
Author(s):  
Goodarz Ahmadi ◽  
Ali Reza Mazaheri ◽  
Duane H. Smith
Keyword(s):  
Continuum Model ◽  
Fluid Flows ◽  
Second Law Of Thermodynamics ◽  
Present Theory ◽  
Elastic Media ◽  
Balance Laws ◽  
Multiphase Mixture ◽  
Multiphase Fluid ◽  
Liquid Flows ◽  
Special Case

Based on the basic balance laws and the second law of thermodynamics, a model for multiphase fluid flows through poro-elastic media is presented. The basic conservation laws. Including the balance of phasic equilibrated forces are are described. Based on the thermodynamics of the multiphase mixture, appropriate constitutive equations are formulated. It is shown that the present theory leads to the extension of Darcy’s law and contains, as its special case, Biot’s (1957) theory of saturated poro-elastic media. The special case of gas-liquid flows in porous media is discussed.

Thin structure of heterogeneous and multiphase fluid flows

2012 ◽  
Vol 9 (1) ◽  
pp. 175-180
Author(s):  
Yu.D. Chashechkin
Keyword(s):  
Large Scale ◽  
Fundamental System ◽  
Fluid Flows ◽  
Regular Solutions ◽  
Flow Models ◽  
Group Methods ◽  
Wide Range ◽  
Thin Structure ◽  
Multiphase Fluid ◽  
Complete Solutions

According to the results of visualization of streams, the existence of structures in a wide range of scales is noted: from galactic to micron. The use of a fundamental system of equations is substantiated based on the results of comparing symmetries of various flow models with the usage of theoretical group methods. Complete solutions of the system are found by the methods of the singular perturbations theory with a condition of compatibility, which determines the characteristic equation. A comparison of complete solutions with experimental data shows that regular solutions characterize large-scale components of the flow, a rich family of singular solutions describes formation of the thin media structure. Examples of calculations and observations of stratified, rotating and multiphase media are given. The requirements for the technique of an adequate experiment are discussed.

A Model Constraint for Polydisperse Solids in Multifluid Flows

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Michael P. Kinzel ◽  
Leonard Joel Peltier ◽  
Brigette Rosendall ◽  
Mallory Elbert ◽  
Andri Rizhakov ◽  
...  
Keyword(s):  
Model Development ◽  
Fluid Flows ◽  
Momentum Exchange ◽  
Carrier Fluid ◽  
Single Carrier ◽  
Cfd Models ◽  
Model Constraint ◽  
Level Model ◽  
Consistency Constraint ◽  
Multiphase Fluid

A method to assess computational fluid dynamics (CFD) models for polydisperse granular solids in a multifluid flow is developed. The proposed method evaluates a consistency constraint, or a condition that an Eulerian multiphase solution for a monodisperse material in a single carrier fluid is invariant to an arbitrary decomposition into a pseudo-polydisperse mixture of multiple, identical fluid phases. The intent of this condition is to develop tests to assist model development and testing for multiphase fluid flows. When applied to two common momentum exchange models, the constraint highlights model failures for polydisperse solids interacting with a multifluid flow. It is found that when inconsistency occurs at the algebraic level, model failure clearly extends to application. When the models are reformulated to satisfy the consistency constraint, simple tests and application-scale simulations no longer display consistency failure.

Pulsatile Waterhammer Subject to Laminar Friction

1972 ◽  
Vol 94 (2) ◽  
pp. 467-472 ◽  
Author(s):  
D. A. P. Jayasinghe ◽  
H. J. Leutheusser
Keyword(s):  
Stokes Equations ◽  
Fluid Motion ◽  
Present Theory ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
One Dimensional ◽  
Arbitrary Velocity ◽  
Velocity Input ◽  
Special Case ◽  
Signalling Problem

This paper deals with elastic waves which may be generated in a fluid by the sudden movement of a flow boundary. In particular, an analysis of the classical piston, or signalling problem is presented for the special case of arbitrary velocity input into a stationary fluid contained in a circular, semi-infinite waveguide. The decay of the pulse, as well as the resulting flow development in the inlet region of the pipe are analyzed by means of an asymptotic expansion of the suitably nondimensionalized Navier-Stokes equations for a compressible, nonheat-conducting Newtonian fluid. The results differ significantly from those of the more conventional one-dimensional approach based on the so-called telegrapher’s equation of mathematical physics. The present theory realistically predicts the growth of a boundary layer both in time and position and, hence, it appears to represent the transient fluid motion in a manner which is physically more appealing.

scholarly journals Momentum-based approximation of incompressible multiphase fluid flows

2017 ◽  
Vol 86 (8) ◽  
pp. 541-563 ◽  
Author(s):  
Loïc Cappanera ◽  
Jean-Luc Guermond ◽  
Wietze Herreman ◽  
Caroline Nore
Keyword(s):  
Fluid Flows ◽  
Multiphase Fluid

Thermodynamic Processes

2019 ◽  
pp. 132-147
Author(s):  
Robert H. Swendsen
Keyword(s):  
Real World ◽  
Heat Engine ◽  
Second Law Of Thermodynamics ◽  
Heat Pumps ◽  
Second Law ◽  
Carnot Cycle ◽  
Heat Engines ◽  
Negative Temperatures ◽  
Special Case ◽  
Thermodynamic Processes

This chapter begins by defining terms critical to understanding thermodynamics: reversible, irreversible, and quasi-static. Because heat engines are central to thermodynamic principles, they are described in detail, along with their operation as refrigerators and heat pumps. Various expressions of efficiency for such engines lead to alternative expressions of the second law of thermodynamics. A Carnot cycle is discussed in detail as an example of an idealized heat engine with optimum efficiency. A special case, called negative temperatures, where temperatures actually exceed infinity, provides further insights. In this chapter we will discuss thermodynamic processes, which concern the consequences of thermodynamics for things that happen in the real world.

scholarly journals ON THE MEASURE-THEORETIC FOUNDATIONS OF THE SECOND LAW OF THERMODYNAMICS

2002 ◽  
Vol 12 (05) ◽  
pp. 721-736 ◽  
Author(s):  
ALFREDO MARZOCCHI ◽  
ALESSANDRO MUSESTI
Keyword(s):  
Measure Theory ◽  
Geometric Measure Theory ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Weak Version ◽  
Balance Laws ◽  
Geometric Measure ◽  
Sets Of Finite Perimeter ◽  
Finite Perimeter ◽  
Theoretic Foundations

Balance laws of the type of entropy are treated in the framework of geometric measure theory, and a weak version, although conceptually simple, of the Second Law of Thermodynamics is introduced, allowing extensions to measure-valued entropy productions and to sets of finite perimeter as subbodies.

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