Permeability of Monodisperse Solid Foams
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Permeability of Monodisperse Solid Foams Olivier Pitois1 · Asmaa Kaddami1 · Vincent Langlois1 Received: 23 January 2020 / Accepted: 29 July 2020 © Springer Nature B.V. 2020
Abstract Fluid permeability of solid foams is a crucial parameter to control transport phenomena in numerous engineering applications, such as heat exchangers or filters for example. Opencell foams with monodisperse pore diameter ranging from 200 to 1000 µm and solid volume fraction ranging from 0.1 to 0.38 are produced and Darcy permeability is measured. The permeability divided by the square of the pore size shows an exponential decay as a function of solid volume fraction. Surprisingly, existing models do not capture this exponential decay and actually they predict permeability values significantly larger than the measured values. The observed exponential decay is then successfully described by using models based on the viscous dissipation occurring through the apertures that connect the foam pores and by accounting for both the mean size of the apertures and the mean number of apertures per pore. Keywords Foam · Darcy · Flow
1 Introduction Open-cell solid foams are attractive materials used in various industries, especially as heat exchangers (Kim et al. 2000) or as thermal insulation materials (Zhang et al. 2014), as crash energy (Jung et al. 2011) or acoustical absorbers (Trinh et al. 2019), as filters for fluids. For many of those applications, permeability is a crucial parameter, as examples, it sets the pressure required to filter a given volume flow rate of fluid, and it is used to model sound absorption through foams (Allard and Atalla 2009). In spite of the significant amount of work devoted to study foam permeability (see (Edouard et al. 2008; Kumar and Topin 2017) for recent reviews), strong discrepancies appear within the literature results. The main reasons for such discrepancies seem to be related to measurement and data treatment issues, to the use of different morphological definitions (number of pores per inch, strut width, strut length, aperture diameter, pore diameter), to the large spectrum of different materials called foams (replication or capillary foams, fully open or partially open cells), to the limited range of void fraction available for each studied foam. * Olivier Pitois [email protected] 1
Lab Navier, ENPC, CNRS, Univ Gustave Eiffel, 77447 Marne‑la‑Vallée, France
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Actually, there is no general consensus to define the link between permeability and foam microstructure, and this limits the development of general models (Edouard et al. 2008). In order to increase our understanding about foam permeability, we perform experiments with monodisperse foams which were produced on purpose with several pore sizes and within a large range of void fraction. As shown in the following, monodispersity is very helpful for careful comparisons to be made with existing models, which will allow highlighting the ability of the so-called aperture model to describe our se
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