Abstract: Molecular dynamics simulation of annular flow
boiling in a nanochannel with 70000 particles is numerically
investigated. In this research, an annular flow model is developed to
predict the superheated flow boiling heat transfer characteristics in a
nanochannel. To characterize the forced annular boiling flow in a
nanochannel, an external driving force F ext ranging from 1to12PN
(PN= Pico Newton) is applied along the flow direction to inlet fluid
particles during the simulation. Based on an annular flow model
analysis, it is found that saturation condition and superheat degree
have great influences on the liquid-vapor interface. Also, the results
show that due to the relatively strong influence of surface tension in
small channel, the interface between the liquid film and vapor core is
fairly smooth, and the mean velocity along the stream-wise direction
does not change anymore.
Abstract: In this paper, the Lennard -Jones potential is applied
to molecules of liquid argon as well as its vapor and platinum as solid
surface in order to perform a non-equilibrium molecular dynamics
simulation to study the microscopic aspects of liquid-vapor-solid
interactions. The channel is periodic in x and y directions and along z
direction it is bounded by atomic walls. It was found that density of
the liquids near the solid walls fluctuated greatly and that the
structure was more like a solid than a liquid. This indicates that the
interactions of solid and liquid molecules are very strong. The
resultant surface tension, liquid density and vapor density are found
to be well predicted when compared with the experimental data for
argon. Liquid and vapor densities were found to depend on the cutoff
radius which induces the use of P3M (particle-particle particle-mesh)
method which was implemented for evaluation of force and surface
tension.