0000000001204116
AUTHOR
J. Hyväluoma
Lattice Boltzmann simulations in microfluidics: probing the boundary condition
In this contribution we summarize our investigations of the effect of boundary slip by utilizing lattice Boltzmann simulations. We investigate fluid flow in hydrophobic and rough microchannels and show that a slip due to hydrophobic interactions increases with increasing hydrophobicity and is independent on the shear rate. If surface roughness is not treated properly while analysing experimental results, a large apparent slip might be measured. We show that the no-slip boundary condition holds in this case if an effective surface position at an intermediate position between peaks and valleys of the surface is considered. Further, we study the effect of microbubbles present on a surface and …
Fluid flow simulations meet high-speed video : Computer vision comparison of droplet dynamics
Hypothesis While multiphase flows, particularly droplet dynamics, are ordinary in nature as well as in industrial processes, their mathematical and computational modelling continue to pose challenging research tasks - patent approaches for tackling them are yet to be found. The lack of analytical flow field solutions for non-trivial droplet dynamics hinders validation of computer simulations and, hence, their application in research problems. High-speed videos and computer vision algorithms can provide a viable approach to validate simulations directly against experiments. Experiments Droplets of water (or glycerol-water mixtures) impacting on both hydrophobic and superhydrophobic surfaces …