Simulations of flow through open cell metal foams using an idealized periodic cell structure

Direct simulation of thermal transport in open-cell metal foams is conducted using different periodic unit cell geometries. The periodic unit cell structures are constructed by assuming the pore space to be spherical and subtracting the pore space from a unit cube of the metal. Different types of packing arrangement for spheres are considered - Body Centered Cubic, Face Centered Cubic, and the A15 lattice (similar to a Weaire-Phelan unit cell) - which give rise to different foam structures. Effective thermal conductivity, pressure drop and Nusselt number are computed by imposing periodic boundary conditions for aluminum foams saturated with air or water. The computed values compare well with existing experimental measurements and semi-empirical models for porosities greater than 80%. The effect of different foam packing arrangements on the computed thermal and fluid flow characteristics is discussed. The capabilities and limitations of the present approach are identified.

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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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Influence of Hydrodynamic Conditions on the Type and Area of Occurrence of Gas–Liquid Flow Patterns in the Flow through Open–Cell Foams

Materials ◽

10.3390/ma13153254 ◽

2020 ◽

Vol 13 (15) ◽

pp. 3254

Author(s):

Roman Dyga ◽

Małgorzata Płaczek

Keyword(s):

Flow Pattern ◽

Liquid Flow ◽

Flow Patterns ◽

Metal Foams ◽

Hydrodynamic Characteristics ◽

Internal Diameter ◽

Open Cell ◽

Flow Through ◽

Open Cell Foams ◽

Gas Liquid Flow

This paper reports the results of a study concerned with air−water and air−oil two–phase flow pattern analysis in the channels with open–cell metal foams. The research was conducted in a horizontal channel with an internal diameter of 0.02 m and length of 2.61 m. The analysis applied three foams with pore density equal to 20, 30 and 40 PPI (pore per inch) with porosity, typical for industrial applications, changing in the range of 92%–94%. Plug flow, slug flow, stratified flow and annular flow were observed over the ranges of gas and liquid superficial velocities of 0.031–8.840 m/s and 0.006–0.119 m/s, respectively. Churn flow, which has not yet been observed in the flow through the open–cell foams, was also recorded. The type of flow patterns is primarily affected by the hydrodynamic characteristics of the flow, including fluid properties, but not by the geometric parameters of foams. Flow patterns in the channels packed with metal foams occur in different conditions from the ones recorded for empty channels so gas−liquid flow maps developed for empty channels cannot be used to predict analyzed flows. A new gas−liquid flow pattern map for a channel packed with metal foams with the porosity of 0.92–0.94 was developed. The map is valid for liquids with a density equal to or lower than the density of water and a viscosity several times greater than that of water.

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Simulation of Thermal Transport in Open-Cell Metal Foams: Effect of Periodic Unit-Cell Structure

Journal of Heat Transfer ◽

10.1115/1.2789718 ◽

2008 ◽

Vol 130 (2) ◽

Cited By ~ 59

Author(s):

Shankar Krishnan ◽

Suresh V. Garimella ◽

Jayathi Y. Murthy

Keyword(s):

Thermal Transport ◽

Pore Space ◽

Cell Structure ◽

Flow Characteristics ◽

Metal Foams ◽

Unit Cube ◽

Unit Cell ◽

Face Centered Cubic ◽

Open Cell ◽

Periodic Unit Cell

Direct simulation of thermal transport in open-cell metal foams is conducted using different periodic unit-cell geometries. The periodic unit-cell structures are constructed by assuming the pore space to be spherical and subtracting the pore space from a unit cube of the metal. Different types of packing arrangement for spheres are considered—body centered cubic, face centered cubic, and the A15 lattice (similar to a Weaire-Phelan unit cell)—which give rise to different foam structures. Effective thermal conductivity, pressure drop, and Nusselt number are computed by imposing periodic boundary conditions for aluminum foams saturated with air or water. The computed values compare well with existing experimental measurements and semiempirical models for porosities greater than 80%. The effect of different foam packing arrangements on the computed thermal and fluid flow characteristics is discussed. The capabilities and limitations of the present approach are identified.

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Porous Bioceramics (Open Cell Foams) Expanded in Vacuum

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.309-311.1023 ◽

2006 ◽

Vol 309-311 ◽

pp. 1023-1026

Author(s):

E.T. Uzumaki ◽

C.S. Lambert

Keyword(s):

Zirconium Oxide ◽

Cell Structure ◽

The Body ◽

Carbon Coatings ◽

Open Cell ◽

Glass Foam ◽

Open Cell Foams ◽

Titanium Foam ◽

Porous Bioceramics ◽

Scanning Electron

In this study, porous bioceramics (titanium foam with diamond-like carbon coatings, glass foam and zirconium oxide foam) were produced using expansion in vacuum. The porosity, the pore size and pore morphology can be adjusted in agreement with the application. The different 3D structures were obtained by varying the parameters of the process. The microstructure and morphology of the porous materials were observed by scanning electron microscopy (SEM) and optical microscopy. The foam exhibit an open-cell structure with interconnected macropores, which provide the potential for tissue ingrowths and the transport of the body fluids.

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New Composite Metal Foams under Compressive Cyclic Loadings

Materials Science Forum ◽

10.4028/www.scientific.net/msf.539-543.1868 ◽

2007 ◽

Vol 539-543 ◽

pp. 1868-1873 ◽

Cited By ~ 14

Author(s):

Afsaneh Rabiei ◽

Brian Neville ◽

Nick Reese ◽

Lakshmi Vendra

Keyword(s):

Maximum Stress ◽

Cell Structure ◽

Hollow Spheres ◽

Metal Foams ◽

Entire Sample ◽

Gravity Casting ◽

Cyclic Compression ◽

High Maximum ◽

Processing Techniques ◽

Very High

New composite metal foams are processed using powder metallurgy (PM) and gravity casting techniques. The foam is comprised of steel hollow spheres, with the interstitial spaces occupied by a solid metal matrix (Al or steel alloys). The cyclic compression loading of the products of both techniques has shown that the composite metal foams have high cyclic stability at very high maximum stress levels up to 68 MPa. Under cyclic loading, unlike other metal foams, the composite metal foams do not experience rapid strain accumulation within collapse bands and instead, a uniform distribution of deformation happen through the entire sample until the densification strain is reached. This is a result of more uniform cell structure in composite metal foams compared to other metal foams. As a result, the features controlling the fatigue life of the composite metal foams have been considered as sphere wall thickness and diameter, sphere and matrix materials, and processing techniques as well as bonding strength between the spheres and matrix.

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CuZnAl Shape Memory Alloys Foams

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.78.31 ◽

2012 ◽

Vol 78 ◽

pp. 31-39 ◽

Cited By ~ 6

Author(s):

Ausonio Tuissi ◽

Paola Bassani ◽

Carlo Alberto Biffi

Keyword(s):

Shape Memory Alloys ◽

Shape Memory ◽

Physical And Mechanical Properties ◽

Metal Foams ◽

Cellular Structures ◽

Metallic Materials ◽

Open Cell ◽

Liquid Infiltration ◽

Highly Porous ◽

Metal Infiltration

Foams and other highly porous metallic materials with cellular structures are known to have many interesting combinations of physical and mechanical properties. That makes these systems very attractive for both structural and functional applications. Cellular metals can be produced by several methods including liquid infiltration of leachable space holders. In this contribution, results on metal foams of Cu based shape memory alloys (SMAs) processed by molten metal infiltration of SiO2 particles are presented. By using this route, highly homogeneous CuZnAl SMA foams with a spherical open-cell morphologies have been manufactured and tested. Morphological, thermo-mechanical and cycling results are reported.

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