Speaker
Description
For decades, multiple studies have focused on test methods to characterize the permeability of fabrics (in plane and transverse permeabilities), both numerically and experimentally [1], [2]. Experimental micro- and macro-models for the characterization of flow in porous media have also been widely studied by the geology community [3], with major applications in gas and petroleum extraction. Nevertheless, despite the fine characterization of fabrics and minerals permeability performed over years, no consensus have been found to properly relate experimental measurements to numerical fluid flow simulations in porous media, principally due to the high variability associated to the materials morphologies and the difficulty to compare the boundary conditions.
To bridge the existing gap between experimental and numerical permeability measurements, we propose to step back to controlled porous media with less variability than fibre-reinforced composites. Similar to Bodaghi et al. who adopted model structures for calibrating their permeability setup [4], we aim to extend this protocol with comparison between experimental results and fluid flow numerical simulations. Our study focuses on gyroid structures (see Fig. 1.b) which present several advantages: (1) the periodicity enables to simulate only one unit cell of the structure, (2) the geometry is tunable (allowing for variation in wall thickness, volume fraction, amplitude and frequency of the gyroid) and (3) it is achievable with additive manufacturing processes. A brief presentation of the numerical and experimental methodologies is given and finally discussed.
The numerical study is divided in two approach : Finite elements and FFT simulations of flows modelled by the Stokes equations. (see results Fig. 1.a). A monolithic approach is used to solve the Stokes finite element problem with a mixed velocity-pressure formulation. This stabilized formulation is based on an unstructured mesh made up of tetrahedral elements of the unit cell poral space. On the other hand, the FFT is based on the voxel description of the gyroids. Different boundary conditions and mesh/voxel refinement levels can then be taken into account. The experimental permeability setup is presented in Baral et al. [5] and illustrated in Fig. 1.c. The pressure delta resulting from the liquid flowing through the 3D structure is measured with a pressure sensor located upstream of the sample. The flow rate is derived from the pressure increase due to the fluid column height, allowing the calculation of saturated permeability in the porous medium.
This study presents a comparative analysis of permeability obtained from fused deposition modelling (FDM) and selective laser melting (SLM) samples, coupled with finite elements and FFT simulations of fluid flow. The results will be discussed based on the experimental surface quality (topography and roughness parameters) as well as the numerical boundary conditions, as they may affect the macroscopic permeability estimation.
| References | [1] E. Syerko et al., ‘Benchmark exercise on image-based permeability determination of engineering textiles: Microscale predictions’, Composites Part A: Applied Science and Manufacturing, vol. 167, p. 107397, Apr. 2023, doi: 10.1016/j.compositesa.2022.107397. [2] A. X. H. Yong et al., ‘Towards standardisation of the out-of-plane permeability measurement for reinforcement textiles’, Composites Part A: Applied Science and Manufacturing, vol. 190, p. 108630, Mar. 2025, doi: 10.1016/j.compositesa.2024.108630. [3] D. Lee et al., ‘Development of stochastically reconstructed 3D porous media micromodels using additive manufacturing: numerical and experimental validation’, Sci Rep, vol. 14, no. 1, p. 9375, Apr. 2024, doi: 10.1038/s41598-024-60075-w. [4] M. Bodaghi, D. Ban, M. Mobin, C. H. Park, S. V. Lomov, and M. Nikzad, ‘Additively manufactured three dimensional reference porous media for the calibration of permeability measurement set-ups’, Composites Part A: Applied Science and Manufacturing, vol. 139, p. 106119, Dec. 2020, doi: 10.1016/j.compositesa.2020.106119. [5] P. Baral, G. Pedoto, and S. Drapier, ‘Indentification of saturated and transient transverse permeability of fibre reinforced fabrics’, in ECCM20 Composites Meet Sustainability, Lausanne, June 2022. |
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| Country | France |
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