One-Dimensional Fully Developed Turbulent Flow through Coarse Porous Medium

2014 ◽  
Vol 19 (7) ◽  
pp. 1491-1496 ◽  
Author(s):  
Mohammad Sedghi-Asl ◽  
Hassan Rahimi ◽  
Javad Farhoudi ◽  
Abdolhossein Hoorfar ◽  
Sven Hartmann
Keyword(s):  
Porous Medium ◽  
Turbulent Flow ◽  
One Dimensional ◽  
Fully Developed Turbulent Flow ◽  
Flow Through

SHOCK PROPAGATION IN A FLOW THROUGH DEFORMABLE POROUS MEDIA: ASYMPTOTIC BEHAVIOUR AS THE POROSITY APPROXIMATES A CONSTANT

2007 ◽  
Vol 17 (08) ◽  
pp. 1261-1278
Author(s):  
ELENA COMPARINI ◽  
MAURA UGHI
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Hydraulic Conductivity ◽  
Asymptotic Behaviour ◽  
Incompressible Flow ◽  
Shock Propagation ◽  
One Dimensional ◽  
Deformable Porous Media ◽  
Flux Intensity ◽  
Flow Through

We consider a one-dimensional incompressible flow through a porous medium undergoing deformations such that the porosity and the hydraulic conductivity can be considered as functions of the flux intensity. We prove that if one approximates the porosity with a constant then the solution of the hyperbolic problem converges to the classical continuous Green–Ampt solution, also in the presence of shocks. In general, however, the shocks remain present in any approximating solution.

Simulation of Turbulent Flow Through Hybrid Porous Medium: Clear Fluid Domains

2000 ◽  
Author(s):  
Marcelo J. S. de Lemos ◽  
Marcos H. J. Pedras
Keyword(s):  
Porous Medium ◽  
Turbulent Flow ◽  
Control Volume ◽  
Numerical Technique ◽  
Governing Equations ◽  
Clear Fluid ◽  
First Case ◽  
Flow Through ◽  
Control Volume Approach ◽  
Porous Obstacle

Abstract Turbulent flow in a channel, totally and partially filled with a porous medium, is simulated with a proposed turbulence model. Two cases are analyzed, namely clear flow past a porous obstacle and flow through a porous medium having a cavity with a higher porosity. Mean and turbulence quantities were solved within both computational domains using a single numerical technique. The control volume approach was used to discretize the governing equations. In the first case analyzed, the flow penetration into the porous substrate is accompanied by generation of turbulence kinetic energy within the obstacle. In the second geometry, the flow is pushed towards the cavity as porosity increases.

Turbulent flow in smooth concentric annuli with small radius ratios

1974 ◽  
Vol 64 (2) ◽  
pp. 263-288 ◽  
Author(s):  
K. Rehme
Keyword(s):  
Reynolds Number ◽  
Shear Stress ◽  
Turbulent Flow ◽  
Strong Influence ◽  
Maximum Velocity ◽  
Small Radius ◽  
Stress Distributions ◽  
Number Range ◽  
Fully Developed Turbulent Flow ◽  
Flow Through

Fully developed turbulent flow through three concentric annuli was investigated experimentally for a Reynolds-number rangeRe= 2 × 104−2 × 105. Measurements were made of the pressure drop, the positions of zero shear stress and maximum velocity, and the velocity distribution in annuli of radius ratios α = 0.02, 0.04 and 0.1, respectively. The results for the key problem in the flow through annuli, the position of zero shear stress, showed that this position is not coincident with the position of maximum velocity. Furthermore, the investigation showed the strong influence of spacers on the velocity and shear-stress distributions. The numerous theoretical and experimental results in the literature which are based on the coincidence of the positions of zero shear stress and maximum velocity are not in agreement with reality.

Brownian deposition of aerosol particles from turbulent flow through pipes

1966 ◽  
Vol 290 (1423) ◽  
pp. 557-562 ◽  
Keyword(s):  
Brownian Motion ◽  
Turbulent Flow ◽  
Aerosol Particles ◽  
Small Particles ◽  
Fully Developed Turbulent Flow ◽  
Flow Through

A previous paper gave an account of a method of calculating the velocity of deposition of aerosol particles upon the wall of a pipe through which they were passing in fully developed turbulent flow. This is now extended to include small particles which diffuse at an appreciable rate owing to their Brownian motion.

scholarly journals Turbulent Flow through and over a Compact Three-Dimensional Model Porous Medium: An Experimental Study

Fluids ◽  
2021 ◽  
Vol 6 (10) ◽  
pp. 337
Author(s):  
James Kofi Arthur
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Turbulent Flow ◽  
Turbulent Flows ◽  
Large Scale ◽  
Three Dimensional ◽  
Compact Model ◽  
Three Dimensional Model ◽  
Filling Fraction ◽  
Flow Through

There are several natural and industrial applications where turbulent flows over compact porous media are relevant. However, the study of such flows is rare. In this paper, an experimental investigation of turbulent flow through and over a compact model porous medium is presented to fill this gap in the literature. The objectives of this work were to measure the development of the flow over the porous boundary, the penetration of the turbulent flow into the porous domain, the attendant three-dimensional effects, and Reynolds number effects. These objectives were achieved by conducting particle image velocimetry measurements in a test section with turbulent flow through and over a compact model porous medium of porosity 85%, and filling fraction 21%. The bulk Reynolds numbers were 14,338 and 24,510. The results showed a large-scale anisotropic turbulent flow region over and within the porous medium. The overlying turbulent flow had a boundary layer that thickened along the stream by about 90% and infiltrated into the porous medium to a depth of about 7% of the porous medium rod diameter. The results presented here provide useful physical insight suited for the design and analyses of turbulent flows over compact porous media arrangements.

Experimental Study of Turbulent Flow in Two-Dimensional Porous Media

2009 ◽  
Author(s):  
Sintia Bejatovic ◽  
Martin Agelinchaab ◽  
Mark F. Tachie
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Turbulent Flow ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Channel Height ◽  
Two Dimensional ◽  
Clear Fluid ◽  
Test Channel ◽  
Flow Through

The paper reports on an experimental investigation of turbulent flow through model two-dimensional porous media. The porous media was bounded on one side by a solid plane wall and on the other side by a zone of clear fluid. The model porous media comprised of square arrays of circular acrylic rods that were inserted into precision holes drilled onto pairs of removable plates. The removable plates were then inserted into groves made in the side walls of the test channel. The rods fill about 59% of the channel height. Different combinations of rod diameter and center-to-center spacing were used to produce solid volume fractions that ranged from 0.11 to 0.44. The Reynolds number based on the bulk velocity of the approach flow and channel height was 16800. A high resolution particle image velocimetry (PIV) system was used to conduct detailed velocity measurements within the porous media and the adjacent clear fluid. The results demonstrate that permeability of the porous medium is more useful in correlating the flow characteristics than the porosity or solid volume fraction. Irrespective of rod diameter or spacing, a decrease in permeability of the porous medium produced a lower value of the dimensionless slip velocity. A decrease in permeability also produced higher resistance to the fluid flow through the porous medium. As a result, a larger fraction of the approach flow is channeled through the clear zone adjacent to a porous medium with lower permeability than those with relatively higher permeability. It was also observed that spatially averaged profiles of the mean velocities and turbulent quantities depend strongly on permeability.

Flow Through a Finite Packed Bed of Spheres: A Note on the Limit of Applicability of the Forchheimer-Type Equation

2004 ◽  
Vol 126 (1) ◽  
pp. 139-143 ◽  
Author(s):  
Agne`s Montillet
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Turbulent Flow ◽  
Flow Regime ◽  
Fluid Velocity ◽  
Type Equation ◽  
Packed Bed ◽  
Turbulent Flow Regime ◽  
Fully Developed Turbulent Flow ◽  
Flow Through

The variation of the pressure drop measured as a function of the fluid velocity through a packed bed of spheres is presented and discussed in the range of particle Reynolds number 30–1500. Based on previous studies, the observed limit of validity of the so-called Forchheimer law may be attributed to the concomitant effects of the finite character of the tested bed and of the transition of flow regime which is marking the beginning of the fully developed turbulent flow regime. The limit of validity of the Forchheimer-type law was formerly noticed by several authors.

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