Behavior of liquid films and droplets in the non-equilibrium region of a downward annular mist flow (comparison of porous and central nozzle mixing methods)

摘要: Abstract Experiments were conducted on the behavior of liquid films and droplets in non-equilibrium region a downward annular mist flow, using vertical pipe about 30 mm dia 6.5 m long, under two extreme conditions air-water mixing with either porous wall or central nozzle to feed water. The onset large disturbance waves was influenced remarkably by method. Axial changes film thickness, wave velocity frequency obtained electrical conductivity water droplet mass flux distributions measured an isokinetic sampling probe. In mixing, occurred farther upstream than mixing. fraction liquid-entrained E axially increased monotonously attained certain constant value, whereas it decreased became constant. For high air velocity, length ( z d ) 70–140. critical thickness depended heavily gas flow contrast upward flow.