### Abstract

Language | English |
---|---|

Pages | 403-404 |

Number of pages | 2 |

Journal | Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science |

Volume | 232 |

Issue number | 3 |

DOIs | |

Publication status | Published - 1 Feb 2018 |

### Fingerprint

### Keywords

- color-gradient lattice Boltzmann model
- wetting boundary scheme
- interfacial force
- immiscible displacement
- contact line movement

### Cite this

*Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science*,

*232*(3), 403-404. https://doi.org/10.1177/0954406218754913

}

*Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science*, vol. 232, no. 3, pp. 403-404. https://doi.org/10.1177/0954406218754913

**Color-gradient lattice Boltzmann modeling of immiscible two-phase flows on partially wetting surface.** / Yu, Yuan; Liu, Haihu; Zhang, Yonghao; Liang, Dong.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Color-gradient lattice Boltzmann modeling of immiscible two-phase flows on partially wetting surface

AU - Yu, Yuan

AU - Liu, Haihu

AU - Zhang, Yonghao

AU - Liang, Dong

PY - 2018/2/1

Y1 - 2018/2/1

N2 - A zero-interfacial-force condition is derived and implemented to improve the wetting boundary scheme for a lattice Boltzmann color-gradient model. This new wetting boundary scheme is validated by two static problems, i.e. a droplet resting on a flat surface and a cylindrical surface, and one dynamic problem, i.e. the capillary filling in a 2 dimensional (2D) channel. In these simulations, we observe that non-physical mass transfer is suppressed and spurious velocities become smaller. Meanwhile, accurate results including dynamic contact line movement are achieved on a broad range of contact angles. The model is then applied to study displacement of immiscible fluids in a 2D channel. Both the displacement velocity and the change rate of finger length are found to exhibit a linear dependence on the contact angle at the viscosity ratio of unity. The displacement velocity decreases but the change rate of finger length increases with increasing capillary number, while the displacement velocity tends to be constant, i.e. two-third of the maximum inlet velocity, at high viscosity ratios or low capillary numbers. In contrast to the displacement velocity, the change rate of finger length is negligible at high viscosity ratios or low capillary numbers, where the finger length is in an equilibrium state, while the equilibrium finger length itself is smaller at a higher viscosity ratio or a lower capillary number.

AB - A zero-interfacial-force condition is derived and implemented to improve the wetting boundary scheme for a lattice Boltzmann color-gradient model. This new wetting boundary scheme is validated by two static problems, i.e. a droplet resting on a flat surface and a cylindrical surface, and one dynamic problem, i.e. the capillary filling in a 2 dimensional (2D) channel. In these simulations, we observe that non-physical mass transfer is suppressed and spurious velocities become smaller. Meanwhile, accurate results including dynamic contact line movement are achieved on a broad range of contact angles. The model is then applied to study displacement of immiscible fluids in a 2D channel. Both the displacement velocity and the change rate of finger length are found to exhibit a linear dependence on the contact angle at the viscosity ratio of unity. The displacement velocity decreases but the change rate of finger length increases with increasing capillary number, while the displacement velocity tends to be constant, i.e. two-third of the maximum inlet velocity, at high viscosity ratios or low capillary numbers. In contrast to the displacement velocity, the change rate of finger length is negligible at high viscosity ratios or low capillary numbers, where the finger length is in an equilibrium state, while the equilibrium finger length itself is smaller at a higher viscosity ratio or a lower capillary number.

KW - color-gradient lattice Boltzmann model

KW - wetting boundary scheme

KW - interfacial force

KW - immiscible displacement

KW - contact line movement

UR - http://journals.sagepub.com/home/pic

U2 - 10.1177/0954406218754913

DO - 10.1177/0954406218754913

M3 - Article

VL - 232

SP - 403

EP - 404

JO - Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science

T2 - Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science

JF - Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science

SN - 0954-4062

IS - 3

ER -