Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
Kinetic theory based lattice-Boltzmann models for multiphase systems
Submission Author:
Maria Rosa Amorim Faria Lisboa , MG , Brazil
Co-Authors:
Maria Rosa Amorim Faria Lisboa, Diogo Nardelli Siebert, Paulo Philippi
Presenter: Maria Rosa Amorim Faria Lisboa
doi://10.26678/ABCM.ENCIT2022.CIT22-0031
Abstract
The Lattice Boltzmann Method (LBM) is a viable alternative to study multiphase systems due to its mesoscopic scale, based on kinetic theory. This characteristic makes LBM capable of recovering the fluid flow macroscopic behavior, while also describing the interface formation induced by intermolecular interaction in multiphase systems. For this reason, a variety of LBM models for multiphase systems are found in the literature. However, the interface region is still a constraint for computer simulations due to its high-density gradients. Some proposed models demonstrate numerical problems, such as instability, truncation errors, discretization errors, and/or high-order moment effects. As a result, most simulations present either parasitic currents, artificial interfacial tension, or anisotropy. To avoid these obstacles, some authors employ heuristic elements or strategies that do not fit into the kinetic theory framework of LBM. The present work is a comparative study of two multiphase LBM models with a solid physical foundation in accordance with the kinetic theory. The chosen models are of the forcing method type. The first model is due to He et al. (He, X., Chen, S., & Zhang, R. (1999). Journal of Computational Physics, 152(2), 642–663) and based on two distribution functions that retrieve the order parameter and the pressure as the zeroth-order moments, using a D2Q9 velocity set. The second model is due to Siebert et al. (Siebert, D. N. N., Philippi, P. C., & Mattila, K. K. K. (2014). Physical Review E, 90(5), 053310.) and based on a single distribution function for density, employing a D2V17 velocity set. The simulations provide density profiles, pressure profiles, vapor-liquid coexistence curves, interface tension charts, and spurious currents diagrams, for each model. This comparison makes it possible to evaluate the strategies adopted by the authors when proposing the models, as well as their suitability to simulate hydrodynamic instabilities.
Keywords
Lattice Boltzmann Method, multiphase flow, two-phase systems, Interface
