Influence of mixture sensitivity and pore size on detonation velocities in porous media

In the drying of porous media, the mass transport occurs in the pores as well as on the surface of the solid. The mechanisms involved can take place simultaneously, influenced by the predominant one and can change depending on the moisture content. In this work, the moisture effective diffusivity was estimated in solids with distinct structural properties in order to verify the predominant mechanisms according to the moisture content, analyzing the influence of the physical properties. The materials studied were NaY Zeolite, Kaolin, Silica and Alumina. The results of diffusion coefficient present a minimum at low moisture content that can be related to pore size.

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EVAPORATION FROM TWO POROUS MEDIA DURING DIURNAL RADIATION CYCLES

Canadian Journal of Soil Science ◽

10.4141/cjss78-053 ◽

1978 ◽

Vol 58 (4) ◽

pp. 465-474

Author(s):

N. K. NAGPAL ◽

L. BOERSMA

Keyword(s):

Porous Media ◽

Pore Size ◽

Water Loss ◽

Maximum Rate ◽

Experimental Period ◽

Evaporative Demand ◽

Flow Equations ◽

Average Value ◽

Saturated Media ◽

Rate Of Evaporation

The process of evaporation from porous media subjected to diurnal radiation cycles was studied. Information about pore size effects on evaporation was also obtained. Two porous media consisting of glass beads with diameters ranging from 53 to 74 μm and from 149 to 210 μm were used. Rates of water loss from the initially saturated media varied during the diurnal cycle. The initial rise in rate of surface irradiation increased the rate of water loss from both media. For the coarser material the rate of evaporation continued to increase for several hours after the maximum rate of irradiation was reached while for the finer material the rate of evaporation reached a maximum value even before the maximum rate of irradiation was attained. As a result, the ratio of the evaporation rates, Ecoarse/Efine, varied during the day from approximately 1.0 during periods of low evaporative demand to 2.60 during periods of high evaporative demand with an average value of 1.47 for the full day. The total amount of water lost per day from each medium remained constant during a 7-day experimental period, even though the surface layers dried out during periods of high irradiation. The pore size dependency of the rate of water loss was shown to be determined by the hydraulic conductivities of the porous media. The rates of water loss predicted by unsaturated water flow equations agreed well with the experimental data.

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The Impact of Pore Size and Pore Connectivity on Single-Phase Fluid Flow in Porous Media

Advanced Engineering Materials ◽

10.1002/adem.201000255 ◽

2010 ◽

Vol 13 (3) ◽

pp. 208-215 ◽

Cited By ~ 14

Author(s):

Zeyun Jiang ◽

Kejian Wu ◽

Gary D. Couples ◽

Jingsheng Ma

Keyword(s):

Porous Media ◽

Fluid Flow ◽

Pore Size ◽

Single Phase ◽

Flow In Porous Media ◽

Pore Connectivity ◽

The Impact ◽

Phase Fluid

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Pore Network Analysis of Zone Model for Porous Media Drying

Mathematical Problems in Engineering ◽

10.1155/2014/624145 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Yuan Yuejin ◽

Zhao Zhe ◽

Nie Junnan ◽

Xu Yingying

Keyword(s):

Porous Media ◽

Pore Size Distribution ◽

Pore Size ◽

Size Distribution ◽

Phase Distribution ◽

Pore Network ◽

Pore Network Model ◽

Zone Model ◽

Drying Process ◽

Isothermal Drying

In view of the fact that the zone model for porous media drying cannot disclose the mechanism of liquid phase distribution effectively, a pore network model for the slow isothermal drying process of porous media was developed by applying the theories of pore network drying and transport-process, which fused the physical parameters of porous media, such as porosity, pore mean diameter, and pore size distribution into the model parameters, and a sand bed drying experiment was conducted to verify the validity of this model. The experiment and simulation results indicate that the pore network model could explain the slow isothermal drying process of porous media well. The pore size distributions of porous media have a great effect on the liquid phase distribution of the drying process. The dual-zone model is suitable for the porous media whose pore size distribution obeys Gaussian distribution, while the three-zone model is suitable for the porous media whose pore size distribution obeys the lognormal distribution when the drying analysis of porous media is conducted.

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Effect of pore size distribution and flow segregation on dispersion in porous media

10.2172/6397687 ◽

1978 ◽

Cited By ~ 1

Author(s):

R.G. Carbonell

Keyword(s):

Porous Media ◽

Pore Size Distribution ◽

Pore Size ◽

Size Distribution

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Magnetic Resonance Velocimetry Measurement of Viscous Flows through Porous Media: Comparison with Simulation and Voxel Size Study

Physics ◽

10.3390/physics3040079 ◽

2021 ◽

Vol 3 (4) ◽

pp. 1254-1267

Author(s):

Martin Bruschewski ◽

Sam Flint ◽

Sid Becker

Keyword(s):

Porous Media ◽

Magnetic Resonance ◽

Measurement Uncertainty ◽

Pore Size ◽

Velocity Data ◽

Voxel Size ◽

3 Dimensional ◽

Magnetic Resonance Velocimetry ◽

Flows Through Porous Media ◽

Good Agreement

Studies that use magnetic resonance velocimetry (MRV) to assess flows through porous media require a sufficiently small voxel size to determine the velocity field at a sub-pore scale. The smaller the voxel size, the less information is lost through the discretization. However, the measurement uncertainty and the measurement time are increased. Knowing the relationship between voxel size and measurement accuracy would help researchers select a voxel size that is not too small in order to avoid unnecessary measurement effort. This study presents a systematic parameter study with a low-Reynolds-number flow of a glycerol–water mixture sent through a regularly periodic porous matrix with a pore size of 5 mm. The matrix was a 3-dimensional polymer print, and velocity-encoded MRV measurements were made at 15 different voxel sizes between 0.42 mm and 4.48 mm. The baseline accuracy of the MRV velocity data was examined through a comparison with a computational fluid dynamics (CFD) simulation. The experiment and simulation show very good agreement, indicating a low measurement error. Starting from the smallest examined voxel size, the influence of the voxel size on the accuracy of the velocity data was then examined. This experiment enables us to conclude that a voxel size of 0.96 mm, which corresponds to 20% of the pore size, is sufficient. The volume-averaged results do not change below a voxel size of 20% of the pore size, whereas systematic deviations occur with larger voxels. The same trend is observed with the local velocity data. The streamlines calculated from the MRV velocity data are not influenced by the voxel size for voxels of up to 20% of the pore size, and even slightly larger voxels still show good agreement. In summary, this study shows that even with a relatively low measurement resolution, quantitative 3-dimensional velocity fields can be obtained through porous flow systems with short measurement times and low measurement uncertainty.

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