Pore design and engineering for filters and membranes

In filtration, the concept of pore size is not easy to define. In microfiltration, there are numerous advantages in employing a surface filtering membrane, rather than one relying on depth filtration mechanisms from a tortuous pore flow channel. Modern manufacturing techniques provide means to produce surface filtering membranes. For filtration, it is shown that a suitable pore design is an array of long thin slots. An analysis of fluid flow through the slots suggests that a short slot is adequate, but experimental data with suspended material indicates that slot length is important. Using long slots and careful control of the flow through the membrane it is possible to filter deforming particles such as oil drops from water.

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Prediction of Fluid Flow in Artificial Cancellous Bone

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.695.393 ◽

2014 ◽

Vol 695 ◽

pp. 393-397

Author(s):

Elsa Syuhada Abdull Yamin ◽

Nor Azwadi Che Sidik

Keyword(s):

Fluid Flow ◽

Pore Size ◽

Surface Area ◽

Pore Diameter ◽

Bone Surface ◽

Flow Conditions ◽

Morphological Aspects ◽

Flow Through ◽

Structure Result ◽

Dynamics Method

The permeability of the blood in the artificial cancellous are affected by certain morphological aspects that include pore diameter, pore size, porosity and the bone surface area. In this study, computational fluid dynamics method is used to study the fluid flow through the cancellous structure. Result of the present work show that geometries with the same porosity and overall volume can have different permeability due to the differences in bone surface area. The hexahedron geometry has the highest permeability under stimulated blood flow conditions, where the cylindrical geometry has the lowest. Linear relationship is found between permeability and the two physical properties, bone surface area and the pore size.

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Laminar flow past the bottom with obstacles – a suspension approximation

Bulletin of the Polish Academy of Sciences Technical Sciences ◽

10.1515/bpasts-2015-0080 ◽

2015 ◽

Vol 63 (3) ◽

pp. 685-695

Author(s):

R. Wojnar ◽

W. Bielski

Keyword(s):

Experimental Data ◽

Spatial Distribution ◽

Fluid Flow ◽

Laminar Flow ◽

Gravity Force ◽

Fluid Viscosity ◽

Suspension Concentration ◽

Flow Past ◽

Flow Through

Abstract From Albert Einstein’s study (1905) it is known that suspension introduced to a fluid modifies its viscosity. We propose to describe the influence of obstacles on the Stokesian flow as a such modification. Hence, we treat the fluid flow through small obstacles as a flow with suspension. The flow is developing past the plane bottom under the gravity force. The spatial distribution of suspension concentration is treated as given, and is regarded as an approximation of different obstacles which modify the fluid flow and change its viscosity. The different densities of suspension are considered, beginning of small suspension concentration until 40%. The influence of suspension concentration on fluid viscosity is analyzed, and Brinkman’s formula as fitting best to experimental data is applied.

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Numerical modeling of heat transfer in the fixed-matrix regenerator working in the Electric Thermal Storage heating system

MATEC Web of Conferences ◽

10.1051/matecconf/201824001008 ◽

2018 ◽

Vol 240 ◽

pp. 01008 ◽

Cited By ~ 1

Author(s):

Piotr Cisek ◽

Dawid Taler ◽

Grzegorz Cisek

Keyword(s):

Heat Transfer ◽

Experimental Data ◽

Nusselt Number ◽

Fluid Flow ◽

Flow Distribution ◽

Thermal Storage ◽

Heating System ◽

Transfer Coefficients ◽

Flow Through ◽

Fixed Matrix

The study presents the concept of Electric Thermal Storage (ETS) central heating system. Thermal Energy Storage (TES) is carried out in the fixed-matrix regenerator. The energy conservation equations, determined for the discharge period of the regenerator operation, are implemented in MATLAB numerical procedures based on the Finite Volume Method (FVM). In the model pressure drops within the system are calculated, both for the airflow through the inner tubes, and between the tubes. The flow distribution calculations show that the assumption of even air flow distribution would not be justified. Subsequently, the values of heat transfer coefficients are determined for the four distinct heat transfer surfaces, for the variable axial coordinate z and during the time of the system operation. The use of two different criterion equations is considered, for determining the mean Nusselt number Num for fluid flow through the concentric annular duct, as well as for the local Nusselt number Nuz calculated for the fluid flow through a circular or non-circular ducts. The most appropriate approach is selected by comparing the calculation results with experimental data. Taking into account the relative error, RMSE, and MAPE values calculated, it may be concluded that the Taler correlation – for non-circular ducts – gives results closer to the experimental data obtained.

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Review and a Theoretical Approach on Pressure Drop Correlations of Flow through Open-Cell Metal Foam

Materials ◽

10.3390/ma14123153 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3153

Author(s):

Huizhu Yang ◽

Yongyao Li ◽

Binjian Ma ◽

Yonggang Zhu

Keyword(s):

Experimental Data ◽

Fluid Flow ◽

Pressure Drop ◽

Metal Foam ◽

Flow Characteristics ◽

Metal Foams ◽

High Porosity ◽

Open Cell ◽

Wide Range ◽

Flow Through

Due to their high porosity, high stiffness, light weight, large surface area-to-volume ratio, and excellent thermal properties, open-cell metal foams have been applied in a wide range of sectors and industries, including the energy, transportation, aviation, biomedical, and defense industries. Understanding the flow characteristics and pressure drop of the fluid flow in open-cell metal foams is critical for applying such materials in these scenarios. However, the state-of-the-art pressure drop correlations for open-cell foams show large deviations from experimental data. In this paper, the fundamental governing equations of fluid flow through open-cell metal foams and the determination of different foam geometry structures are first presented. A variety of published models for predicting the pressure drop through open-cell metal foams are then summarized and validated against experimental data. Finally, two empirical correlations of permeability are developed and recommended based on the model of Calmidi. Moreover, Calmidi’s model is proposed to calculate the Forchheimer coefficient. These three equations together allow calculating the pressure drop through open-cell metal foam as a function of porosity and pore diameter (or strut diameter) in a wide range of porosities ε = 85.7–97.8% and pore densities of 10–100 PPI. The findings of this study greatly advance our understanding of the flow characteristics through open-cell metal foam and provide important guidance for the design of open-cell metal foam materials for different engineering applications.

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Molybdenum systematics of subducted crust record reactive fluid flow from underlying slab serpentine dehydration

Nature Communications ◽

10.1038/s41467-019-12696-3 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 6

Author(s):

Shuo Chen ◽

Remco C. Hin ◽

Timm John ◽

Richard Brooker ◽

Ben Bryan ◽

...

Keyword(s):

Experimental Data ◽

Fluid Flow ◽

Isotopic Fractionation ◽

Fluid Phase ◽

Oceanic Lithosphere ◽

Reactive Fluid ◽

Flow Through ◽

Slab Dehydration ◽

Reactive Fluid Flow ◽

Mo Isotopes

Abstract Fluids liberated from subducting slabs are critical in global geochemical cycles. We investigate the behaviour of Mo during slab dehydration using two suites of exhumed fragments of subducted, oceanic lithosphere. Our samples display a positive correlation of δ98/95MoNIST 3134 with Mo/Ce, from compositions close to typical mantle (−0.2‰ and 0.03, respectively) to very low values of both δ98/95MoNIST 3134 (−1‰) and Mo/Ce (0.002). Together with new, experimental data, we show that molybdenum isotopic fractionation is driven by preference of heavier Mo isotopes for a fluid phase over rutile, the dominant mineral host of Mo in eclogites. Moreover, the strongly perturbed δ98/95MoNIST 3134 and Mo/Ce of our samples requires that they experienced a large flux of oxidised fluid. This is consistent with channelised, reactive fluid flow through the subducted crust, following dehydration of the underlying, serpentinised slab mantle. The high δ98/95MoNIST 3134 of some arc lavas is the complement to this process.

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Fluid Flow Through Porous Metals

Journal of Applied Mechanics ◽

10.1115/1.4010218 ◽

1951 ◽

Vol 18 (1) ◽

pp. 39-45 ◽

Cited By ~ 8

Author(s):

Leon Green ◽

Pol Duwez

Keyword(s):

Experimental Data ◽

Reynolds Number ◽

Porous Medium ◽

Fluid Flow ◽

Quadratic Equation ◽

General Definition ◽

Porous Metals ◽

Flow Through ◽

Definition Of

Abstract A method is outlined for correlating experimental data obtained in studies of the flow of gases and liquids through porous metals. The correlation is based upon the suggestion of Forcheimer that the pressure gradient attending the flow of a liquid through a porous medium can be expressed as a function of flow rate by a simple quadratic equation. An equation of this type defines two length parameters necessary for characterization of a porous structure and permits a general definition of the Reynolds number for a structure of arbitrary complexity.

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