to measure weight of the liquid flowing from the
test section outlet over a sufficient time, whereas the flow rates
of gases were measured by three sets of rotameters within the
range of 5–50, 50–500, and 200–2500 cm3
/min, respectively. An
air–water y-shaped mixer served to introduce fluids smoothly
along the test section. Thermocouples and pressure transducers
were installed at various positions to monitor the flow condition
of the working fluids