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Unifying fluidization and defluidization of granular columns
Phys. Rev. E 111, 045421 – Published 18 April, 2025
DOI: https://doi.org/10.1103/PhysRevE.111.045421
Abstract
We study air pressure during the fluidization and defluidization of granular columns with the aim to unify the description of these processes. To this end, we perform experiments with different air flow velocities and columns of different heights. The experimental measurements evidence a nonlinear relationship between pressure and the depth in the column. This complex pressure profile challenges the conventional framework of Darcy's law, typically used to analyze airflow in granular columns. We introduce a law that effectively captures these nonlinear effects, occurring even at low particle Reynolds numbers. An advantage of our approach is its applicability to defluidization—a key phenomenon in gravity-driven gas-particle flows. Using this law, we present a model to describe the decrease of air pressure in a defluidizing column, with numerical simulations aligning well with experimental results.
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References (21)
- O. Roche, Depositional processes and gas pore pressure in pyroclastic flows: An experimental perspective, Bull Volcanol 74, 1807 (2012).
- D. Geldart, Gas Fluidization Technology (Wiley, NY, 1986).
- A. Delebarre, Does the minimum fluidization exist? J. Fluids Eng. 124, 595 (2002).
- S. Ergun, Fluid flow through packed columns, Chem. Eng. Prog. 48, 89 (1952).
- A. Anantharaman, R. A. Cocco, and J. W. Chew, Evaluation of correlations for the minimum fluidization velocit () in gas-solid fluidization, Powder Technol. 323, 454 (2018).
- M. Rasteh, G. Ahmadi, and S. H. Hosseini, Effect of Gaussian size distribution owidth on minimum fluidization velocity in tapered gas-solid fluidized beds, Particuology 66, 71 (2022).
- A. Rao, J. S. Curtis, B. C. Hancock, and W. C., The effect of column diameter and bed height on minimum fluidization velocity, AIChE J. 56, 2304 (2010).
- H. Quan, N. Fatah, and C. Hu, Diagnosis of hydrodynamic regimes from large to micofluidized beds, Chem. Eng. J. 391, 123615 (2020).
- Z. Jiang and N. Fatah, New investigation of micro-fluidized bed: The effect of wall roughness and particle size on hydrodynamics regimes, Chem. Eng. J. 430, 133075 (2022).
- E. Breard, L. Jones, J.and Fullard, G. Lube, C. Davies, and J. Dufek, The permeability of volcanic mixtures-implications for pyroclastic currents, J. Geophys. Res.: Solid Earth 124, 1343 (2019).
- S. Leibrandt and J. L.-Le Pennec, Towards fast and routine analyses of volcanic ash morphometry for eruption surveillance applications, J. Volcanol. Geotherm. Res. 297, 11 (2015).
- E. C. P. Breard, J. Dufek, and G. Lube, Enhanced mobility in concentrated pyroclastic density currents: An examination of a self-fluidization mechanism, Geophys. Res. Lett. 45, 654 (2018).
- R. M. Fand, B. Y. K. Kim, A. C. C. Lam, and R. T. Phan, Resistance to the fow of fuids through simple and complex porous media whose matrices are composed of randomly packed spheres, J. Fluids Eng. 109, 268 (1987).
- W. Sobieski and A. Trykozko, Darcy's and Forchheimer's laws in practice. Part 1. The experiment, Tech. Sci. 17, 321 (2014).
- H. A. Janssen, Versuche über getreidedtruck in silozellen, Z. Ver. Dtsh. Ing 39, 1045 (1895).
- S. M. Brice, M. Georgelin, S. Deville, and A. Pocheau, Wall friction and Janssen effect in the solidification of suspensions, Soft Matter 14, 9498 (2018).
- I. Rosenhek-Goldian, N. Kampf, and J. Klein, Trapped aqueous films lubricate highly hydrophobic surfaces, ACS Nano 12, 10075 (2018).
- J. D. Goddard, Nonlinear elasticity and pressure-dependent wave speeds in granular media, Proc. R. Soc. London A 430, 105 (1990).
- C. F. Schreck, T. Bertrand, C. S. O'Hern, and M. D. Shattuck, Repulsive contact interactions make jammed particulate systems inherently nonharmonic, Phys. Rev. Lett. 107, 078301 (2011).
- E. T. Owens and K. E. Daniels, Sound propagation and force chains in granular materials, Europhys. Lett. 94, 54005 (2011).
- N. Mahabadi and J. Jang, The impact of fluid flow on force chains in granular media, Appl. Phys. Lett. 110, 041907 (2017).
