scholarly journals Transient Fluid Motions in Saturated Porous Media

1957 ◽  
Vol 10 (1) ◽  
pp. 43 ◽  
Author(s):  
JR Philip

The transition from rest to steady motion on the sudden application of a potential gradient to the fluid contained in a saturated porous medium is investigated. An approximate analysis gives the result that the time of the effective establishment of the steady motion is proportional to the permeability and inversely proportional to the kinematic viscosity. Two exact solutions (one of them new) for simple cases suggest that the approximate analysis is remarkably accurate. An analogy between this problem and one in heat conduction makes the relevant results in that field immediately applicable here.

2019 ◽  
Vol 9 (3) ◽  
pp. 225-231 ◽  
Author(s):  
Du Xinqiang ◽  
Song Yalin ◽  
Ye Xueyan ◽  
Luo Ran

Abstract Column experiments were conducted to examine the clogging effects of colloids under controlled conditions of solution ionic strength (IS) and porous media roughness. The results showed that colloids in recharge water play an important role in the clogging process of saturated porous media, such that even a small amount of colloid may cause a large reduction in the permeability of the porous medium. Clogging at the pore throat was inferred to be the main reason for the severe permeability reduction of porous media. The characteristics of colloid clogging were clearly influenced by both IS and medium roughness. Recharge water with a higher IS facilitated greater attachment of colloids to the surface of the saturated porous medium, which lead to superficial clogging, while collectors with a rough surface resulted in greater clogging than collectors with a smooth surface.


Author(s):  
A. V. Kuznetsov ◽  
A. A. Avramenko

In this paper, a model of bioconvection in a suspension of gyrotactic motile microorganisms in a fluid saturated porous medium is suggested. The microorganisms considered in this paper are heavier than water and gyrotactic behavior results in their swimming towards the regions of most rapid downflow. Because of that, the regions of downflow become denser than the regions of upflow. Buoyancy increases the upward velocity in the regions of upflow and downward velocity in the regions of downflow, thus enhancing the velocity fluctuations. The experiments performed by Kessler (1986) and the numerical results of Kuznetsov and Jiang (2001) indicate that if the permeability of porous medium is sufficiently small it will prevent the development of convection instability. However, for practical purposes, in order to maximize the flux of the cells in the upward direction it is desirable to have the permeability of the porous medium as high as possible. The aim of this paper is to investigate the value of critical permeability. If permeability is smaller than this critical value bioconvection does not occur and microorganisms simply swim in the upward direction.


2006 ◽  
Vol 129 (6) ◽  
pp. 727-734 ◽  
Author(s):  
H. Sakamoto ◽  
F. A. Kulacki

Measurements are reported of heat transfer coefficients in steady natural convection on a vertical constant flux plate embedded in a saturated porous medium. Results show that heat transfer coefficients can be adequately determined via a Darcy-based model, and our results confirm a correlation proposed by Bejan [Int. J. Heat Mass Transfer. 26(9), 1339–1346 (1983)]. It is speculated that the reason that the Darcy model works well in the present case is that the porous medium has a lower effective Prandtl number near the wall than in the bulk medium. The factors that contribute to this effect include the thinning of the boundary layer near the wall and an increase of effective thermal conductivity.


2013 ◽  
Vol 135 (6) ◽  
Author(s):  
D. A. Nield ◽  
A. V. Kuznetsov

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.


2017 ◽  
Vol 39 (3) ◽  
pp. 40-46
Author(s):  
A.A. Avramenko ◽  
N.P. Dmitrenko ◽  
Y.Y. Kovetskaya

The paper investigates linear and nonlinear hydrodynamic instability of flow in channel ocuped porous medium. The effects of linear instability are considered using the method of linear perturbations. The nonlinear instability of the flow is considered using the renormalized expression for the coefficient of the kinematic viscosity.


Author(s):  
Liming Dai ◽  
Guoqing Wang

This research is to investigate the behavior of elastic waves in porous media consisting of fluid and solid. A new methodology for describing the wave motion of a fluid-saturated porous medium is developed with the establishment of a mathematical wave model. Dynamic equations in the form of displacements of the fluid and solid are derived for analyzing the elastic waves propagating in homogeneous and isotropic porous media, which are subjected to excitations of multiple energy sources. Solutions of the wave equation are developed on the basis of the moving-coordinate method. Numerical simulations of the waves propagating in the porous media with multiple energy sources are also performed for demonstrating the application of the mathematical model developed.


2009 ◽  
Vol 132 (1) ◽  
Author(s):  
V. V. Sobha ◽  
R. Y. Vasudeva ◽  
K. Ramakrishna ◽  
K. Hema Latha

Thermal dispersion due to local flows is significant in heat transfer with forced convection in porous media. The effects of parametrized melting (M), thermal dispersion (D), inertia (F), and mixed convection (Ra/Pe) on the velocity distribution, temperature, and Nusselt number on non-Darcy, mixed convective heat transfer from an infinite vertical plate embedded in a saturated porous medium are examined. It is observed that the Nusselt number decreases with increase in melting parameter and increases with increase in thermal dispersion.


2020 ◽  
Author(s):  
Yuri Perepechko ◽  
Konstantin Sorokin ◽  
Georgiy Vasilyev

<p>The aim of the research is to construct a mathematical model of the formation of a fracture system in magma intrusion in the permeable zones of the lithosphere and on this basis to study the formation of magmatic channels in the lithosphere and crust. The lithosphere substrate is modeled by a saturated porous medium in which the processes of small-scale destruction in the mantle magma intrusion lead to the formation of faults and, consequently, to a magmatic channel. Destruction and occurrence of micro-fracture fields can be associated with both magma flow and external seismic effect leading to the rock breaking. The process of small-scale destruction is described within the framework of the dynamics of the elastoplastic fracture-porous medium and causes variations in the rheological properties of the lithosphere substrate. A feature of this process is the destruction substrate in the compression zone represented by a narrow area with a sharply changing concentration of micro-fractures. The micro-fracture accumulation provides the conversion of the broken area into a macro-fissure. The elastoplastic porous matrix in the destruction zone contains both broken and intact substrate, the relative content of which is determined by relaxation of deformations, the speed of which depends on stress and yield stress point according to the power law. The obtained mathematical model provides investigation of currents in fractured-porous media and their effect on the small-scale destruction. Based on the TVD-Runge Kutta method numerical simulation of the compressible fluid infiltration into the fracture-porous permeable channel has shown that stresses in the compression domain can reach stress limits of breaking and result in fracture formation. Change in relaxation time does not result in a marked change in stress fields. The concentration of maximum stresses is observed in the channel center leading to an increase in its fracture porosity. The computational results show the appearance of high stress values in the compression domain in the process of a liquid phase injection, for instance, magma, into a low-permeable fracture-porous layer. The introduction of the destruction criterion will help to associate the occurrence of such regions to the local breaking of the porous matrix. Thus, the proposed micro-fracture generation mechanism can be used to describe the formation of fracture or channels in micro-fracture porous media. Work is done on state assignment of IGM SB RAS with partial support from the Russian Foundation for Basic Research, grants No. 16-29-15131, 19-05-00788.</p>


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