Dispersion in Metal Foam: A Pore Scale Numerical Study

2012 ◽  
Vol 326-328 ◽  
pp. 410-415
Author(s):  
Jean Michel Hugo ◽  
Frédéric Topin
Keyword(s):  
Metal Foam ◽  
Numerical Study ◽  
Fluid Phase ◽  
Numerical Approach ◽  
Representative Elementary Volume ◽  
Pore Scale ◽  
Elementary Volume ◽  
Foam Sample ◽  
Mass Fluxes ◽  
Phase Conductivity

We determine thermal dispersion in metal foams using a pore scale numerical approach. Samples are contained in a channel crossed by a steady fully established fluid flow. The size of the foam sample is chosen according to a Representative Elementary Volume (REV).Two configurations are tested with several foam structures, pore size and pore shape. In the first configuration, heat and mass fluxes are in the same direction, in the second one, fluxes are perpendicular such as in heat exchanger. Results obtained on apparent fluid phase conductivity are discussed along with pressure drop data and compared to available literature data.

scholarly journals Numerical study of pore-scale flow and noise of an open cell metal foam

2018 ◽  
Vol 82-83 ◽  
pp. 185-198 ◽  
Author(s):  
Chen Xu ◽  
Yijun Mao ◽  
Zhiwei Hu
Keyword(s):  
Metal Foam ◽  
Numerical Study ◽  
Pore Scale ◽  
Open Cell

About Thermo-Hydraulic Properties of Open Cell Foams: Pore Scale Numerical Analysis of Strut Shapes

2014 ◽  
Vol 354 ◽  
pp. 195-200
Author(s):  
Prashant Kumar ◽  
Frédéric Topin
Keyword(s):  
Fluid Phase ◽  
Local Thermal Equilibrium ◽  
Geometrical Parameters ◽  
Pore Scale ◽  
Flow Parameters ◽  
Inertia Coefficient ◽  
Analytical Correlation ◽  
Thermal Equilibrium Condition ◽  
Phase Conductivity ◽  
Open Cell Foams

The thermo-physical behavior of open-celled metal foams depends on their microscopic structure. Various ideal periodic isotropic structures of tetrakaidecahedron shapes with constant cross section of the ligament having circular, square, diamond, hexagon and star strut shapes with various orientations are studied. We have proposed a generalized analytical model in order to obtain geometrical parameters correctly and various relationships between different geometrical parameters and porosities (60-95%) are presented. We have also studied the flow parameters namely permeability and inertia coefficient for different strut shapes and various Reynolds number (0.00001<Re<3000). The range of solid to fluid phase conductivity ratios (λs/λf) studied is from 10 to 30000 for different porosities in local thermal equilibrium condition and an analytical correlation is proposed comprising geometrical parameters of foam structure.

INVESTIGATIONS ON REPRESENTATIVE ELEMENTARY VOLUME AND DIRECTIONAL PERMEABILITY OF FRACTAL-BASED FRACTURE NETWORKS USING POLYGON SUB-MODELS

Fractals ◽  
2020 ◽  
Vol 28 (05) ◽  
pp. 2050085
Author(s):  
JING ZHANG ◽  
RICHENG LIU ◽  
LIYUAN YU ◽  
HONGWEN JING ◽  
QIAN YIN
Keyword(s):  
Preferential Flow ◽  
Numerical Study ◽  
Length Distribution ◽  
Fracture Network ◽  
Representative Elementary Volume ◽  
Polar Coordinate System ◽  
Elementary Volume ◽  
Fracture Length ◽  
Directional Permeability ◽  
Dfn Model

Since the directional permeability of fractured rock masses is significantly dependent on the geometric properties of fractures, in this work, a numerical study was performed to analyze the relationships between them, in which fracture length follows a fractal distribution. A method to estimate the representative elementary volume (REV) size and directional permeability ([Formula: see text] by extracting regular polygon sub-models with different orientation angles ([Formula: see text] and side lengths ([Formula: see text] from an original discrete fracture network (DFN) model was developed. The results show that the fracture number has a power law relationship with the fracture length and the evolution of the exponent agrees well with that reported in previous studies, which confirms the reliability of the proposed fractal length distribution and stochastically generated DFN models. The [Formula: see text] varies significantly due to the influence of random numbers utilized to generate fracture location, orientation and length when [Formula: see text] is small. When [Formula: see text] exceeds some certain values, [Formula: see text] holds a constant value despite of [Formula: see text], in which the model scale is regarded as the REV size and the corresponding area of DFN model is represented by [Formula: see text] (in 2D). The directional permeability contours for DFN models plotted in the polar coordinate system approximate to circles when the model size is greater than the REV size. The [Formula: see text] decreases with the increment of fractal dimension of fracture length distribution ([Formula: see text]. However, the decreasing rate of [Formula: see text] (79.5%) when [Formula: see text] increases from 1.4 to 1.5 changes more significantly than that (34.8%) when [Formula: see text] increases from 1.5 to 1.6 for regular hexagon sub-models. This indicates that the small non-persistent fractures dominate the preferential flow paths; thereafter, the flow rate distribution becomes more homogeneous when [Formula: see text] exceeds a certain value (i.e. 1.5). A larger [Formula: see text] results in a denser fracture network and a stronger conductivity.

A Review of Numerical Study on Explosion and Shock Wave Resistance of Metal Foam Material

2014 ◽  
Vol 936 ◽  
pp. 2024-2029
Author(s):  
Jian Kun Yi ◽  
Huang Shen ◽  
Ke Bin Yan ◽  
Bing Gao
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Metal Foam ◽  
Numerical Study ◽  
Numerical Algorithms ◽  
Numerical Approach ◽  
Status Quo ◽  
Wave Resistance ◽  
Foam Material ◽  
The Status

The goal of this research is to understand the status quo and trend of research on numerical simulation of explosion and shock wave resistance of metal foam material. Methods of modelling metal foam material and numerical algorithms of explosion and shock, as well as the current advances in two aspects have been briefly reviewed. Some problems existing in numerical simualtion of explosion and shock wave resistance of metal foam material have also been pointed out. Conclusions of this research will be of benefit to study explosion and shock wave resistance of metal foam material using numerical approach farther.

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