Physics of Fluids - Publications

An efficient phase-field method for turbulent multiphase flows

arΧiv
Journal of Computational Physics 446, 110659 (2021)

Authors

	Haoran Liu
	Chong Shen Ng
	Steven Chong
	Detlef Lohse
	Roberto Verzicco

BibTeΧ

@article{LIU2021110659,
title = {An efficient phase-field method for turbulent multiphase flows},
journal = {Journal of Computational Physics},
volume = {446},
pages = {110659},
year = {2021},
issn = {0021-9991},
doi = {https://doi.org/10.1016/j.jcp.2021.110659},
url = {https://www.sciencedirect.com/science/article/pii/S0021999121005544},
author = {Hao-Ran Liu and Chong Shen Ng and Kai Leong Chong and Detlef Lohse and Roberto Verzicco},
keywords = {Turbulence, Multiphase flow, Phase-field method, Biharmonic term, High performance computation},
abstract = {With the aim of efficiently simulating three-dimensional multiphase turbulent flows with a phase-field method, we propose a new discretization scheme for the biharmonic term (the 4th-order derivative term) of the Cahn-Hilliard equation. This novel scheme can significantly reduce the computational cost while retaining the same accuracy as the original procedure. Our phase-field method is built on top of a direct numerical simulation solver, named AFiD (www.afid.eu) and open-sourced by our research group. It relies on a pencil distributed parallel strategy and a FFT-based Poisson solver. To deal with large density ratios between the two phases, a pressure split method [1] has been applied to the Poisson solver. To further reduce computational costs, we implement a multiple-resolution algorithm which decouples the discretizations for the Navier-Stokes equations and the scalar equation: while a stretched wall-resolving grid is used for the Navier-Stokes equations, for the Cahn-Hilliard equation we use a fine uniform mesh. The present method shows excellent computational performance for large-scale computation: on meshes up to 8 billion nodes and 3072 CPU cores, a multiphase flow needs only slightly less than 1.5 times the CPU time of the single-phase flow solver on the same grid. The present method is validated by comparing the results to previous studies for the cases of drop deformation in shear flow, including the convergence test with mesh refinement, and breakup of a rising buoyant bubble with density ratio up to 1000. Finally, we simulate the breakup of a big drop and the coalescence of O(103) drops in turbulent Rayleigh-B√©nard convection at a Rayleigh number of 108, observing good agreement with theoretical results.}
}