6 research outputs found
Fluidic gates simulated with lattice Boltzmann method under different Reynolds numbers
© 2018 Elsevier B.V. Fluidic devices use fluid as a medium for information transfer and computation. Boolean values are represented by the presence of fluid jets in the input and output channels. Velocity of a fluid is one of the parameters determining Reynolds number of the flow. Reynolds number is a parameter that characterizes the behaviour of the flow: laminar, transient or turbulent. Using lattice Boltzmann method we study the behaviour of fluidic gates for various Reynolds numbers. On the designs of AND and OR gates we show the fluidic gates remain functional even for low Reynolds numbers, like 100. The gates designed can be cascaded into functional logical circuits
Droplet deformation by short laser-induced pressure pulses
When a free-falling liquid droplet is hit by a laser it experiences a strong
ablation driven pressure pulse. Here we study the resulting droplet deformation
in the regime where the ablation pressure duration is short, i.e. comparable to
the time scale on which pressure waves travel through the droplet. To this end
an acoustic analytic model for the pressure-, pressure impulse- and velocity
fields inside the droplet is developed in the limit of small density
fluctuations. This model is used to examine how the droplet deformation depends
on the pressure pulse duration while the total momentum to the droplet is kept
constant. Within the limits of this analytic model, we demonstrate that when
the total momentum transferred to the droplet is small the droplet
shape-evolution is indistinguishable from an incompressible droplet
deformation. However, when the momentum transfer is increased the droplet
response is strongly affected by the pulse duration. In this later regime,
compressed flow regimes alter the droplet shape evolution considerably.Comment: Submitted to JF
Axisymmetric multiphase lattice Boltzmann method for generic equations of state
We present an axisymmetric lattice Boltzmann model based on the Kupershtokh et al. multiphase model that is capable of solving liquid–gas density ratios up to 103. Appropriate source terms are added to the lattice Boltzmann evolution equation to fully recover the axisymmetric multiphase conservation equations. We validate the model by showing that a stationary droplet obeys the Young–Laplace law, comparing the second oscillation mode of a droplet with respect to an analytical solution and showing correct mass conservation of a propagating density wave
Axisymmetric multiphase lattice Boltzmann method for generic equations of state
We present an axisymmetric lattice Boltzmann model based on the Kupershtokh et al. multiphase model that is capable of solving liquid–gas density ratios up to 103. Appropriate source terms are added to the lattice Boltzmann evolution equation to fully recover the axisymmetric multiphase conservation equations. We validate the model by showing that a stationary droplet obeys the Young–Laplace law, comparing the second oscillation mode of a droplet with respect to an analytical solution and showing correct mass conservation of a propagating density wave