scholarly journals Validity of the One-Dimensional Limp Model for Porous Media

10.14311/1017 ◽  
2008 ◽  
Vol 48 (3) ◽  
Author(s):  
O. Doutres ◽  
N. Dauchez ◽  
J.-M. Genevaux ◽  
O. Dazel
Keyword(s):  
Porous Media ◽  
Porous Materials ◽  
Material Properties ◽  
Analytical Modeling ◽  
Fluid Model ◽  
Biot Model ◽  
One Dimensional ◽  
Rigid Frame ◽  
The One ◽  
Frame Stiffness

A straightforward criterion for determining the validity ofthe limp model validity for porous materials is addressed here. The limp model is an “equivalent fluid” model which gives a better description of porous behavior than the well known “rigid frame” model. It is derived from the poroelastic Biot model, assuming that the frame has no bulk stiffness. A criterion is proposed for identifying the porous materials for which the limp model can be used. It relies on a new parameter, the Frame Stiffness Influence FSI, based on porous material properties. The critical values of FSI under which the limp model can be used are determined using 1D analytical modeling for a specific boundary set: radiation of a vibrating plate covered by a porous layer. 

A Linear Stability Analysis for an Improved One-Dimensional Two-Fluid Model

2003 ◽  
Vol 125 (2) ◽  
pp. 387-389 ◽  
Author(s):  
Jin Ho Song
Keyword(s):  
Stability Analysis ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Fluid Model ◽  
Two Phase ◽  
One Dimensional ◽  
Proposed Model ◽  
Two Fluid Model ◽  
The One ◽  
Two Fluid

A linear stability analysis is performed for a two-phase flow in a channel to demonstrate the feasibility of using momentum flux parameters to improve the one-dimensional two-fluid model. It is shown that the proposed model is stable within a practical range of pressure and void fraction for a bubbly and a slug flow.

Review of Applicability of the One-dimensional Two-fluid Model to the Prediction of Wave Growth and Slug Evolution in Horizontal Pipes

2010 ◽  
Author(s):  
Raad I. Issa ◽  
Liejin Guo ◽  
D. D. Joseph ◽  
Y. Matsumoto ◽  
Y. Sommerfeld ◽  
...  
Keyword(s):  
Fluid Model ◽  
Wave Growth ◽  
One Dimensional ◽  
Horizontal Pipes ◽  
Two Fluid Model ◽  
The One ◽  
Two Fluid

Article

1998 ◽  
Vol 76 (11) ◽  
pp. 1633-1641
Author(s):  
Luc Tremblay ◽  
Serge Lacelle ◽  
Charles G Fry
Keyword(s):  
Porous Media ◽  
Pyrex Glass ◽  
Nmr Imaging ◽  
Porous Network ◽  
Intensity Correlation ◽  
Geometric Means ◽  
Statistical Characterization ◽  
One Dimensional ◽  
Intensity Fluctuations ◽  
The One

A study of the intensity fluctuations in one-dimensional NMR microimaging profiles of imbibed porous Pyrex glass filters is presented. An approach to characterize some aspects of the macroscopic randomness from the NMR microimaging profiles of this porous medium is developed. Statistical properties, such as the arithmetic and geometric means, of the distributions of peak separations between the intensity fluctuations are shown to reveal information about the pore size and the pore-to-pore distances in porous media. The intensity-intensity correlation functions of the one-dimensional NMR profiles display an interplay, as a function of length scale, among the dimensions of the porous network and its embedding space, and their respective dimensions in the projections. Corroboration of these NMR results are achieved with similar analysis of SEM two-dimensional images and their corresponding one-dimensional projections obtained with the same porous Pyrex glass. The approach developed to characterize the macroscopic randomness in these porous glass filters should prove generic for the study of other random materials.Key words: NMR imaging, scanning electron microscopy, porous media, disorder, statistical characterization.

An Historical and Topical Note on Convection in Porous Media

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
D. A. Nield ◽  
A. V. Kuznetsov
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Porous Materials ◽  
Analytical Modeling ◽  
Single Phase ◽  
Saturated Porous Media ◽  
Early Literature ◽  
The Third ◽  
Convection In Porous Media

This note deals with three main themes. The first is a discussion of the early literature on convection in porous media. The second is a brief overview of current analytical modeling of single-phase convection in saturated porous media and in composite fluid/porous-medium domains. The third is a brief discussion of some pertinent recent studies involving nanofluids, cellular porous materials, bidisperse and tridisperse porous media.

Subcritical Flutter in Collapsible Tube Flow: A Model of Expiratory Flow in the Trachea

1991 ◽  
Vol 113 (1) ◽  
pp. 21-26 ◽  
Author(s):  
C. Walsh ◽  
P. A. Sullivan ◽  
J. S. Hansen
Keyword(s):  
Fluid Model ◽  
One Dimensional ◽  
Shell Effects ◽  
Collapsible Tubes ◽  
Dimensional Modeling ◽  
Axial Tension ◽  
Normal Wall ◽  
Axial Curvature ◽  
The One ◽  
Axial Stretching

Using an axisymmetric geometry that retains certain qualitative features of the trachea, we extend one-dimensional modeling of flow in collapsible tubes to include both curved shell effects and, for untethered tubes, wall inertia. A systematic scaling of the finite deformation membrane equations leads to an approximate set which is consistent with the one-dimensional fluid model; axial and normal wall variables are coupled elastically, but only axial inertia is retained. Transverse curvature causes elastic coupling that can give rise to axial wall motion and a flutter instability. The source of instability is the product of a nonzero reference axial curvature with axial tension variation due to axial stretching. The numerical results suggest that this mechanism may be significant even in processes which cannot be assumed one-dimensional.

Analysis of thick beams with temperature-dependent material properties under thermomechanical loads

2020 ◽  
Vol 23 (9) ◽  
pp. 1838-1850 ◽  
Author(s):  
Zhong Zhang ◽  
Ding Zhou ◽  
Xiuli Xu ◽  
Xuehong Li
Keyword(s):  
Material Properties ◽  
Mechanical Load ◽  
Stress Fields ◽  
Steel Beam ◽  
State Space Method ◽  
Temperature Dependent ◽  
One Dimensional ◽  
Simply Supported ◽  
The One ◽  
Space Method

This study focuses on the thermoelastic behavior of simply supported thick beams with temperature-dependent material properties under thermomechanical loads. The heat conduction analysis is based on the one-dimensional Fourier’s law, and the displacement and stress analysis is based on the two-dimensional thermoelasticity theory. The solution of temperature field across the thickness is obtained. By dividing the beam into a series of thin slices, the temperature and the material properties in each slice are considered to be uniform. The state space method is used to give the displacements and stresses for every slice. The transfer-matrix method is used to give the displacements and stresses for the beam. Finally, an example is conducted to analyze the temperature, displacement, and stress fields in a carbon steel beam. The example reveals that the temperature not only produces displacements and stresses itself but also affects the displacements and stresses induced by the mechanical load.

Proposed Use of the One-Dimensional Two-Fluid Model With Momentum Flux Parameters

2000 ◽  
Author(s):  
Jin Ho Song ◽  
H. D. Kim
Keyword(s):  
Differential Equations ◽  
Void Fraction ◽  
Momentum Flux ◽  
Fluid Model ◽  
Sufficient Conditions ◽  
Wave Number ◽  
One Dimensional ◽  
Two Fluid Model ◽  
The One ◽  
Two Fluid

Abstract The dynamic character of a system of the governing differential equations for the one-dimensional two-fluid model, where the appropriate momentum flux parameters are employed to consider the velocity and void fraction distribution in a flow channel, is analyzed. In response to a perturbation in the form of a traveling wave, a linear stability analysis is performed for the governing differential equations. The analytical expression for the growth factor as a function of wave number, void fraction, drag coefficient, and relative velocity is derived. It provides the necessary and sufficient conditions for the stability of the one-dimensional two-fluid model in terms of momentum flux parameters. It is analytically shown that the one-dimensional two-fluid model is mathematically well posed by use of appropriate momentum flux parameters, while the conventional two-fluid model makes the system unconditionally unstable. It is suggested that the velocity and void distributions should be properly accounted for in the one-dimensional two-fluid model by use of momentum flux parameters.

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