Influence of sample thickness and measurement set-up on the experimental evaluation of permeability of metallic foams

Innocentini, M. D. M.; Lefebvre, Louis‐Philippe; Meloni, R. V.; Baril, Éric

doi:10.1007/s10934-009-9312-5

Cited by 24 publications

(13 citation statements)

References 25 publications

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“…In general, the pressure drop in the cancellous bone is influenced by physical parameters such as length, porosity and bone surface area as governed by the Darcy's and Forchheimer's laws [65]. On top of that, Vossenberg et al [45] reported that the interaction between wall and fluid could cause a pressure drop in cancellous structures.…”

Section: Discussionmentioning

confidence: 99%

Permeability study of cancellous bone and its idealised structures

Syahrom

Kadir

Harun

et al. 2015

Medical Engineering & Physics

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Section: Discussionmentioning

confidence: 99%

Permeability study of cancellous bone and its idealised structures

Syahrom

Kadir

Harun

et al. 2015

Medical Engineering & Physics

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“…For F 0 b b1, viscous effects are dominant on the flow, while for F 0 N N 1 the pressure drop is due mainly to inertial effects [50]. The individual contributions of viscous and inertial effects to total pressure drop from this parameter can thus be estimated as follows: Table 3 reports the calculated F 0 and Fig.…”

Section: Flow Regimementioning

confidence: 99%

Permeability and mechanical integrity of porous biomorphic SiC ceramics for application as hot-gas filters

et al. 2016

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Biomorphic SiC is a biotemplated material fabricated by Si melt-infiltration of carbon preforms from wood pyrolysis. In this work, porous bioSiC ceramics from five different wood precursors, with porosities between 45 and 72% were studied for their feasibility in filtering applications. Gas permeability and mechanical stability were investigated as a function of the microstructure of the starting wood precursor. Air-permeation performance at room temperature was measured for a range of flow rates, and the permeability constants were assessed by fitting of Forchheimer's equation to the experimental data. Darcian permeabilities were achieved in the range 10 −11 -10 −12 m 2 , while inertial terms were in the range 10 −7 -10 −8 m, showing a correlation with the average pore size and orientation of the larger channels. Regarding the mechanical stability, maximum compressive strength values were reached in the range of 3-115 MPa. These results improve our understanding of the ways in which the microstructure influences permeability and mechanical robustness, enabling the device requirements to be tailored by selecting the wood precursor. It was also shown that these materials are promising for hot-gas filtering applications.

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“…The characteristic length scale used to define the Reynolds number for consolidated porous media depends to the conformation of the internal network. The average pores' diameter is usually selected as characteristic dimension for metallic and composite foams [30][31][32] . The average fibers' diameter, or the hydraulic diameter based on the radius and on the volume fraction of the fibers, is commonly used for fibrous composite materials 21,26 .…”

Section: Basic Concepts For Permeability Measurementsmentioning

confidence: 99%

“…Indeed, the compressibility of the gas inside the porous material is taken into account by introducing the mean pressure in the core during the measurements (Eq. (6)) 32 . The permeability with respect to gaseous fluids, provided by Eq.…”

Section: Basic Concepts For Permeability Measurementsmentioning

confidence: 99%

Permeability Measurements of Complex Porous Structures for Reusable Thermal Protection Systems (Invited)

Gulli

Maddalena

McKelvey

et al. 2014

19th AIAA International Space Planes and Hypersonic Systems and Technologies Conference

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Reusable thermal protection systems are one of the key technologies that have to be improved in order to afford long-duration hypersonic flights. Transpiration cooling has been demonstrated to be one of the most promising active cooling techniques in terms of temperature decreasing and coolant mass saving. The coupling of the boundary layer with the thermal response of selected porous materials plays a crucial role in enabling the practical use of the transpiration cooling technique for reusable thermal protection systems. In this work, a novel test-rig for the non-intrusive characterization in terms of local permeability of a customized porous Carbon-Carbon nose-tip is proposed. The new concept of effective permeability, conceived as the local blowing capability of a porous structure with respect to a selected coolant fluid, is also introduced. The coolant (air) mass-fluxes blown from the porous surface of the specimen, and measured by a hot-film probe, are related to the average pressure gradient across the local material thickness by using the Darcy's law on prescribed locations. A parallel work, based on the X-Ray computed tomography scan of the prototype specimen, has been carried out with the purpose of defining the most important guidelines for the effective-permeability tests. Specifically, the calculation of the average porosity is used to define the minimum area to be probed with the hot-wire. The analysis of the statistical distribution of the void structures inside the C/C cone, coupled to the use of the theory of fluid-flow through perforated plates, is performed to determine the correct distance of the hot-wire from the wall. The results show permeability variation among the surveyed locations ranging from 6% to 172%. The effective-permeability map obtained allows classifying the prototype C/C mask as a semi-pervious structure. In particular, the higher effective permeability is located near the stagnation point region where two delaminations are located. The asymmetric blowing capability of the cone highlights the importance of characterizing the entire thermal protection system instead of defining the overall properties of the material, which can be drastically different at the full-scale level due to the geometry, the system integration and the intrinsic defectology due to the manufacturing process. Nomenclature= slope of the chart pressure gradient vs. Darcy's velocity, ( • / 2 ) = transversal distance from the wall, ( .) ℎ = channels' diameter, ( ) = diameter of the control points, ( .) = local specimen's thickness, ( .) 2 ̿ = permeability tensor, ( 2 ) = permeability for the r-direction, ( ) = length, ( ) = merging or coalescence distance, ( .) ̇ = measured flow rate, ( ) = network-mesh size, ( .) = external pressure, ( ) = internal-plenum pressure, ( ) = external-plenum pressure, ( ) 2 = coefficient of determination, (−) ℎ = Reynolds number based on the channel's diameter, (−) = time, ( ) = calibration temperature, ( ) = hot-film temperature, ( ) = measured temperature during permeability tes...

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Influence of sample thickness and measurement set-up on the experimental evaluation of permeability of metallic foams

Cited by 24 publications

References 25 publications

Permeability study of cancellous bone and its idealised structures

Permeability study of cancellous bone and its idealised structures

Permeability and mechanical integrity of porous biomorphic SiC ceramics for application as hot-gas filters

Permeability Measurements of Complex Porous Structures for Reusable Thermal Protection Systems (Invited)

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