Joint estimation of hydraulic conductivities of two sand samples in a W-tube system with a bi-exponential response

2015 ◽  
Vol 47 (2) ◽  
pp. 344-355 ◽  
Author(s):  
Mariusz Kaczmarek ◽  
Filip Wolny ◽  
Marek Marciniak
Keyword(s):  
Hydraulic Conductivity ◽  
Water Flow ◽  
Optimization Procedure ◽  
Joint Estimation ◽  
Exponential Rate ◽  
Tube System ◽  
Two Samples ◽  
Independent Constant ◽  
Flow Through ◽  
Constant Head

The motivation for this paper is the practical problem of interpreting bi-exponential rate-of-rise curves that are observed during many field piezometric tests. In the authors' previous study, a laboratory W-tube system of water flow through two samples of sand was introduced with an adequate mathematical model. The desired bi-exponential character of water flow was obtained by placing two different samples of sand in separate but connected columns. In the present paper, a so-called inverse problem is solved. The optimization procedure is applied in order to jointly estimate a pair of hydraulic conductivity values based on experimentally recorded bi-exponential rate-of-rise curves. The obtained values of hydraulic conductivities are presented and compared to the values determined from independent constant-head permeability tests conducted for the analyzed sands. The results of this identification procedure varied in accuracy. The mean percent errors between the hydraulic conductivity values measured jointly and independently for the analyzed experimental series were in the range of 8.8 to 37.2%. The discussion presents the restrictions of this interpretational method and suggests further modeling plans.

scholarly journals An Empirical Model for Estimation of Permeability of Porous Media based on its Gradation Parameters

2020 ◽  
Vol 8 (5) ◽  
pp. 669-673
Keyword(s):  
Porous Media ◽  
Hydraulic Conductivity ◽  
Empirical Model ◽  
Low Head ◽  
Flow Through ◽  
Constant Head

In the present study the hydraulic conductivity of the porous media has been related to its gradation parameters. Nine cohesion-less soils of different gradations were tested in a constant head permeameter. A low head of water, standardised to viscosity at 20°C, was used to avoid the turbulence. It was observed that the hydraulic conductivity varied significantly with respect to the gradation parameters. The empirical model developed on the basis of this study can be helpful for more rational estimation of the flow through non-cohesive porous media on the basis of its gradation characteristics.

Osmotic flow through a Cretaceous clay in southern Saskatchewan, Canada

2001 ◽  
Vol 38 (5) ◽  
pp. 1025-1033 ◽  
Author(s):  
Bradley D Cey ◽  
S L Barbour ◽  
M Jim Hendry
Keyword(s):  
Hydraulic Conductivity ◽  
Pore Fluid ◽  
Experimental Program ◽  
Diffuse Double Layer ◽  
Semipermeable Membranes ◽  
Osmotic Flow ◽  
Fluid Concentration ◽  
Osmotic Behaviour ◽  
Flow Through ◽  
Constant Head

Clays and shales can act as semipermeable membranes, causing osmotic flow and (or) osmotically induced fluid pressures. Despite laboratory proof of the osmotic behaviour of clay-rich geologic material, the influence of this osmotic behaviour on in situ groundwater flow and solute transport is inconclusive. This is due in part to the lack of laboratory experimental work involving undisturbed core samples, and to the lack of field-scale research. The ability of undisturbed clay samples to conduct flow hydraulically and osmotically was investigated using dilute salt solutions. Undisturbed Cretaceous clay samples from southern Saskatchewan were used in a laboratory experimental program. The experiments included constant-head hydraulic conductivity (Kh) tests and osmotic flow tests conducted over a range of pore-fluid concentrations of 0.054–1.12 equiv./L. The clay samples exhibited semipermeable membrane behaviour by conducting flow osmotically. The hydraulic conductivity of the clay increased by a factor of two as the pore-fluid concentration increased from 0.070 to 0.56 equiv./L. Osmotic efficiencies ranged from 0.0028 to 0.42 for concentrations from 0.84 to 0.096 equiv./L. Both the osmotic compressibility and osmotic efficiency decreased with increasing pore-fluid concentration. The behaviour of the clay was consistent with diffuse double-layer theory.Key words: osmotic flow, Cretaceous clay, salt, hydraulic conductivity.

Resistance to water flow in Fagus grandifolia leaves

1977 ◽  
Vol 55 (20) ◽  
pp. 2591-2599 ◽  
Author(s):  
M. T. Tyree ◽  
Y. N. S. Cheung
Keyword(s):  
Hydraulic Conductivity ◽  
Water Flow ◽  
Shortest Path ◽  
Activation Energies ◽  
Fagus Grandifolia ◽  
Xylem Vessel ◽  
Mesophyll Cells ◽  
Water Efflux ◽  
Flow Through ◽  
Pressure Driven

The tempo of water efflux from single Fagus grandifolia leaves has been measured. The resistance to pressure-driven water efflux has been measured for normal leaves, Rs, and for leaves in which extracellular mesophyll spaces are infiltrated with water, Rs*. The ratio Rs*/Rs is about 0.4. The resistance to water flow through the xylem, Rx, was also measured and found to be a small part of Rs, i.e., Rx/Rs = 0.08. The activation energies for water efflux from normal and infiltrated leaves are both about 26 ± 4 kJ/mol.After an analysis of our data, we conclude that the membrane hydraulic conductivity of F. grandifolia leaves is roughly 10−6 cm s−1 bar−1 (1 bar = 100 kPa) and that water travels the shortest path between the cell sap and the nearest xylem vessel, flowing in and out of mesophyll cells through the areas in contact between adjacent cells along the pathway.

HEAT TRANSFER BURNOUT IN WATER FLOW THROUGH ROUND TUBES AND ANNULI

1970 ◽  
Author(s):  
B. A. Zenkevich ◽  
P. L. Kirillov ◽  
G. V. Alekseev ◽  
O. L. Peskov ◽  
O. A. Sudnitsyn
Keyword(s):  
Heat Transfer ◽  
Water Flow ◽  
Flow Through

Modeling of Reduced Water Flow through Concrete Caused by Crystallization Technology

2006 ◽  
Vol 9 (8) ◽  
pp. 723-730
Author(s):  
Abdelaziz Al-Khlaifat ◽  
Awni Al-Otoom
Keyword(s):  
Water Flow ◽  
Flow Through ◽  
Reduced Water

scholarly journals Determination of cross-sectional void fraction in a two-phase water flow through a PVC pipe

2021 ◽  
Vol 655 (1) ◽  
pp. 012024
Author(s):  
O.H. Ajesi ◽  
M.B. Latif ◽  
S.T. Gbenu ◽  
C. A. Onumejor ◽  
M. K. Fasasi ◽  
...  
Keyword(s):  
Water Flow ◽  
Void Fraction ◽  
Two Phase ◽  
Cross Sectional ◽  
Flow Through ◽  
Pvc Pipe ◽  
Phase Water

Lattice Boltzmann simulation of water flow through rough nanopores

2021 ◽  
Vol 236 ◽  
pp. 116329
Author(s):  
Zhilin Cheng ◽  
Zhengfu Ning ◽  
Dong-Hun Kang
Keyword(s):  
Water Flow ◽  
Lattice Boltzmann ◽  
Lattice Boltzmann Simulation ◽  
Flow Through
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