Volume 9, Issue 5
Roughness Effects on Continuous and Discrete Flows in Superhydrophobic Microchannels

Junfeng Zhang & Daniel Y. Kwok

Commun. Comput. Phys., 9 (2011), pp. 1094-1105.

Published online: 2011-05

Preview Full PDF 137 753
Export citation
  • Abstract

The dynamic behaviors of continuous and discrete flows in superhydrophobic microchannels are investigated with a lattice Boltzmann model. Typical characters of the superhydrophobic phenomenon are well observed from our simulations, including air trapped in the surface microstructures, high contact angles, low contact angle hysteresis, and reduced friction to fluid motions. Increasing the roughness of a hydrophobic surface can produce a large flow rate through the channel due to the trapped air, implying less friction or large apparent slip. The apparent slip length appears to be independent to the channel width and could be considered as a surface property. For a moving droplet, its behavior is affected by the surface roughness from two aspects: the contact angle difference between its two ends and the surface-liquid interfacial friction. As a consequence, the resulting droplet velocity changes with the surface roughness as firstly decreasing and then increasing. Simulation results are also compared with experimental observations and better agreement has been obtained than that from other numerical method. The information from this study could be valuable for microfluidic systems.

  • Keywords

  • AMS Subject Headings

  • Copyright

COPYRIGHT: © Global Science Press

  • Email address
  • BibTex
  • RIS
  • TXT
@Article{CiCP-9-1094, author = {Junfeng Zhang and Daniel Y. Kwok}, title = {Roughness Effects on Continuous and Discrete Flows in Superhydrophobic Microchannels}, journal = {Communications in Computational Physics}, year = {2011}, volume = {9}, number = {5}, pages = {1094--1105}, abstract = {

The dynamic behaviors of continuous and discrete flows in superhydrophobic microchannels are investigated with a lattice Boltzmann model. Typical characters of the superhydrophobic phenomenon are well observed from our simulations, including air trapped in the surface microstructures, high contact angles, low contact angle hysteresis, and reduced friction to fluid motions. Increasing the roughness of a hydrophobic surface can produce a large flow rate through the channel due to the trapped air, implying less friction or large apparent slip. The apparent slip length appears to be independent to the channel width and could be considered as a surface property. For a moving droplet, its behavior is affected by the surface roughness from two aspects: the contact angle difference between its two ends and the surface-liquid interfacial friction. As a consequence, the resulting droplet velocity changes with the surface roughness as firstly decreasing and then increasing. Simulation results are also compared with experimental observations and better agreement has been obtained than that from other numerical method. The information from this study could be valuable for microfluidic systems.

}, issn = {1991-7120}, doi = {https://doi.org/10.4208/cicp.151009.270910s}, url = {http://global-sci.org/intro/article_detail/cicp/7538.html} }
TY - JOUR T1 - Roughness Effects on Continuous and Discrete Flows in Superhydrophobic Microchannels AU - Junfeng Zhang & Daniel Y. Kwok JO - Communications in Computational Physics VL - 5 SP - 1094 EP - 1105 PY - 2011 DA - 2011/05 SN - 9 DO - http://dor.org/10.4208/cicp.151009.270910s UR - https://global-sci.org/intro/cicp/7538.html KW - AB -

The dynamic behaviors of continuous and discrete flows in superhydrophobic microchannels are investigated with a lattice Boltzmann model. Typical characters of the superhydrophobic phenomenon are well observed from our simulations, including air trapped in the surface microstructures, high contact angles, low contact angle hysteresis, and reduced friction to fluid motions. Increasing the roughness of a hydrophobic surface can produce a large flow rate through the channel due to the trapped air, implying less friction or large apparent slip. The apparent slip length appears to be independent to the channel width and could be considered as a surface property. For a moving droplet, its behavior is affected by the surface roughness from two aspects: the contact angle difference between its two ends and the surface-liquid interfacial friction. As a consequence, the resulting droplet velocity changes with the surface roughness as firstly decreasing and then increasing. Simulation results are also compared with experimental observations and better agreement has been obtained than that from other numerical method. The information from this study could be valuable for microfluidic systems.

Junfeng Zhang & Daniel Y. Kwok. (1970). Roughness Effects on Continuous and Discrete Flows in Superhydrophobic Microchannels. Communications in Computational Physics. 9 (5). 1094-1105. doi:10.4208/cicp.151009.270910s
Copy to clipboard
The citation has been copied to your clipboard