| Summary: | The visualitation and the time variation of liquid hold-up in a horizontal air-water
stratified flow (26.0 mm ID and 9.5 m in total length) has been investigated
experimentally. In the present experimental study, the visualisation study was
carried-out from the analizing of the visual data obatined from the video camera
and the liquid film behavior was investigated by measure the instantaneous local
liquid hold-up by using a Constant Electric Current Method (CECM). The
principle of this method is on the basis of the conductivity ratio of the two-phase
components. Here we used three pairs of liquid hold-up sensors arranged with an
axial spacing of 215 mm. As a result it was found that : (1) Both the visual and the
signal characterization of the interfacial wave can be used to determine the flow
sub-regime in air-water stratified flow. In the smooth stratified sub-regime, no
wave were observed and dominant liquid value in probability distribution function
(PDF) were cumulated into a narrow. Meanwhile, in the stratified wavy + ripple
(SR), stratified wavy + roll (SW), and pseudo-slug (PS) sub-regimes, the
interfacial wave were appeared and dominant liquid value in probability
distribution function (PDF) were spreaded, (2) the average liquid hold-up
increases as the water superficial velocity increases, meanwhile it decreases as
the air superficial velocity increases, (3) in the same flow sub-regime, the wave
velocity increases as the air superficial velocity increases, and (4) in the stratified
wavy+ripple (SR,) dominant frequency decreases as the air superficial velocity
increases.
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