ISSN Online: 2379-1748
ISBN Flash Drive: 978-1-56700-472-4
ISBN Online: 978-1-56700-471-7
3rd Thermal and Fluids Engineering Conference (TFEC)
LIQUID PLUG IN GAS FLOWIN ANNULAR CHANNEL
Abstract
In this paper, we used a 4th order PDE to describe the plug flow in micro-scale annular and found a series
solution for it. The influence of geometry parameters (dimensionless plug length β, and inner-outer radius
ratio η) upon the flow pattern was investigated in details with the aspects of vortex center locations, the
intensity ratio between the vortex near the inner wall (inner vortex) and that near the outer wall (outer vortex),
the radial velocity distribution and the particle recirculation time. The skin friction coefficients Cƒ were also
investigated under different parameter combinations. Two asymptomatic situations (β → ∞, η → 0) were done to validate with existing models. There are two major findings: First, the flow pattern would be greatly
influenced by the inner-outer radius ratio η. The higher η makes the flow tend to be like plug flow in a 2-
D microchannel with symmetric patterns. The lower η creates two different vortexes. Second, Cƒ could be influenced by both β and η. Overall Cƒ drops nearly exponentially with growing β. Cƒ would also increase
with growing η, and this trend is more obvious for relatively longer plugs.