Improved contact angle measurement in multiphase lattice Boltzmann

Abstract

Contact angle is an essential parameter to indicate substrate wettability. The measurement of contact angle in experiments and simulations is a complex and time-consuming work. In this paper, we propose an improved measuring method of contact angle in multiphase lattice Boltzmann simulations, which can accurately obtain the real-time contact angle at low temperatures and larger density ratios. The three-phase contact point is determined by an extrapolation, and its position is not affected by the local deformation of flow field at the three-phase contact region. A series of simulations confirm that the present method has high accuracy and gird-independence. The contact angle keeps an excellent linear relationship with the chemical potential of the surface, so that it is very convenient to specify the wettability of a surface. The real-time contact angle measurement enables us to obtain the dynamic contact angle hysteresis on chemically heterogeneous surfaces, while the mechanical analyses can be effectively implemented at the moving contact line.

A discrete Boltzmann model with symmetric velocity discretization for compressible flow

“…One popular computational technique in association with the Boltzmann equation is the lattice Boltzmann method (LBM), which has been successfully developed for simulations of fluid phenomena. [2][3][4][5][6][7][8][9][10][11][12][13][14] The LBM research consists of two complementary branches. One aims to serve as a novel approach for numerically solving various partial differential equation(s).…”