The application of Buckingham π theorem to Lattice-Boltzmann modelling of sewage sludge digestion



Dapelo, Davide ORCID: 0000-0002-3442-6857, Trunk, Robin, Krause, Mathias J, Cassidy, Nigel and Bridgeman, John ORCID: 0000-0001-8348-5004
(2020) The application of Buckingham π theorem to Lattice-Boltzmann modelling of sewage sludge digestion. COMPUTERS & FLUIDS, 209. p. 104632.

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Abstract

For the first time, a set of Lattice-Boltzmann two-way coupling pointwise Euler-Lagrange models is applied to gas mixing of sludge for anaerobic digestion. The set comprises a local model, a “first-neighbour” (viz., back-coupling occurs to the voxel where a particle sits, plus its first neighbours) and a “smoothing-kernel” (forward- and back-coupling occur through a smoothed-kernel averaging procedure). Laboratory-scale tests display grid-independence problems due to bubble diameter being larger than voxel size, thereby breaking the pointwise Euler-Lagrange assumption of negligible particle size. To tackle this problem and thereby have grid-independent results, a novel data-scaling approach to pointwise Euler-Lagrange grid independence evaluation, based on an application of the Buckingham π theorem, is proposed. Evaluation of laboratory-scale flow patterns and comparison to experimental data show only marginal differences in between the models, and between numerical modelling and experimental data. Pilot-scale simulations show that all the models produce grid-independent, coherent data if the Euler-Lagrange assumption of negligible (or at least, small) particle size is recovered. In both cases, a second-order convergence was achieved. A discussion follows on the opportunity of applying the proposed data-scaling approach rather than the smoothing-kernel model.

Item Type: Article
Uncontrolled Keywords: Anaerobic digestion, Grid independence, Lattice-Boltzmann, Euler-Lagrange, Non-Newtonian, OpenLB
Divisions: Faculty of Science and Engineering > School of Engineering
Depositing User: Symplectic Admin
Date Deposited: 17 May 2023 10:19
Last Modified: 05 Oct 2023 12:10
DOI: 10.1016/j.compfluid.2020.104632
Open Access URL: https://doi.org/10.1016/j.compfluid.2020.104632
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3170420