Lattice Boltzmann parallel simulation of microflow dynamics over structured surfaces

Abstract

In the present work, a parallel lattice Boltzmann multiphase model was developed to investigate the effects of surface structures on wettabilities and flow dynamics in a microchannel. The theory of wetting transition was firstly discussed. Then three types including triangular, rectangle and hierarchical shaped microstructures were constructed on the surface to examine the effects on wettabilities and drag reduction. It was found that flow behaviour is strongly affected by the surface morphology of the channel. The results indicated that hierarchical structures on the surface could improve the hydrophobicity significantly. For rectangular structures, they can improve the hydrophobicity with the increase of height and distance ratio h/d of the structures, and the improvement will reach its optimal hydrophobicity when the value h/d is over a certain value of 0.6. Moreover, to accelerate computational speed, the Open Multi-Processing (OpenMP) was employed for the parallelization of the model. A maximum speedup of 2.95 times was obtained for 4 threads on a multi-core CPU platform.

A Comprehensive Review of Wetting Transition Mechanism on the Surfaces of Microstructures from Theory and Testing Methods

“…LBM is a good choice from mesoscopic state for the simulation of superhydrophobic surface. There are numerous studies of superhydrophobic surface simulation using LBM, such as contact angle of microdroplets on superhydrophobic surface [31][32][33][34][35][36] and wetting transition between Cassie and Wenzel [37,38]. FVM is a In recent decades, with the development of computer science, computer simulation has become a vital research method.…”

Focus on Bioinspired Textured Surfaces toward Fluid Drag Reduction: Recent Progresses and Challenges

“…[80] Copyright 2017, IOP Publishing Ltd. Reproduced with permission. [222] Copyright 2017, Elsevier Ltd. B) Schematic diagram of liquid-gas-solid interface on an SHS. C) Schematic diagram of water sliding on the surface.…”

“…Figure 7. A) Contact angle state of droplet on surface: (a) static contact angle of smooth surface; (b) Wenzel state; (c) Cassie-Baxter state.Reproduced with permission [222]. Copyright 2017, Elsevier Ltd. B) Schematic diagram of liquid-gas-solid interface on an SHS.…”

Proportional scaling molecular dynamics simulations of the wetting experiments of water droplets on ink-patterned printing paper

“…7 However, most research is analyzed from a macroperspective via the lattice Boltzmann method (LBM) and the computational uid dynamics (CFD) method. [8][9][10][11][12] The approach of molecular dynamics (MD), which is regarded as an efficient and practical simulation method, 13 may obtain atomistic information in the simulation of wetting behaviors and eliminate the issues associated with experimental noise and turbulence. 14 In the MD simulation, the droplet and solid surface are constantly downscaled to the nanoscale for minimal computer usage.…”