Coupling Lattice Boltzmann Gas and Level Set Method for Simulating Free Surface Flow in GPU/CUDA Environment

In this paper, we develop a new computational framework to investigate the sloshing free surface flow of Newtonian and non-Newtonian fluids in the rectangular tanks. We simulate the flow via a two-phase model and employ the fixed unstructured mesh in the computation to avoid the mesh distortion and reconstruction. As for the solution of Navier–Stokes equation, we utilize the SUPG finite element method based on the splitting scheme. The same order interpolation functions are then used for velocity and pressure. Moreover, the moving interface is captured via the concise level set method. We take advantage of the implicit discontinuous Galerkin method to handle the solution of level set and its reinitialization equations. A mass correction technique is also added to ensure the mass conservation property. The dam break-free surface flow is simulated firstly to demonstrate the validity of our mathematical model. In addition, the sloshing Newtonian fluid in the tank with flat and rough bottoms is considered to illustrate the feasibility and robustness of our computational scheme. Finally, the development of free surface for non-Newtonian fluid is also studied in the two tanks, and the influence of power-law index on the sloshing fluid flow is analyzed.

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A lattice-Boltzmann free surface model for injection moulding of a non-Newtonian fluid

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2019.0407 ◽

2020 ◽

Vol 378 (2175) ◽

pp. 20190407 ◽

Cited By ~ 1

Author(s):

Daniele Chiappini

Keyword(s):

Free Surface ◽

Lattice Boltzmann ◽

Injection Moulding ◽

Soft Matter ◽

Density Ratio ◽

Acrylonitrile Butadiene Styrene ◽

Free Surface Flow ◽

Surface Flow ◽

Surface Model ◽

Free Surface Model

The aim of this work is to present a lattice Boltzmann (LB) model devoted to dealing with non-Newtonian free surface flow. The combination of LB solver with a free-surface model allows dealing with multiphase flows where the density ratio in between the two considered phases is so high that the lighter phase can be neglected. For this particular set of multiphase models, the interface between the two phases is numerically reconstructed and transported via a diffusion equation. Moreover, the application of a Carreau approach for viscosity modelling allows the introduction of effects related to shear stress on fluid flow evolution. Two different non-Newtonian silicon-like materials have been considered here, namely the polystyrene and acrylonitrile butadiene styrene. Here, the author, after the mandatory model validation with a reference configuration, presents some applications of injection moulding for two different test-cases: the former is the injection in a labyrinth-like gasket, whereas the latter is the injection in a porous media. This article is part of the theme issue ‘Fluid dynamics, soft matter and complex systems: recent results and new methods’.

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