2010 Volume 58 Issue 680 Pages 245-253
The disintegration process of a water jet issued from a 1.9mm-diameter nozzle into an otherwise quiescent atmosphere in microgravity was observed with a high-speed camera in order to compare to the corresponding conventional results for vertically downward issued water jets under normal gravity condition. The range of liquid Weber number is varied from zero to three, keeping the issued liquid flow laminar. Consistent with our prediction, the breakup lengths obtained in the microgravity experiments are shorter than those obtained in the laboratory experiments. In the microgravity experiment, no disintegration was observed in the final state unless the liquid Weber number exceeds unity, and the breakup length increases linearly from zero when the Weber number exceeds unity. This is significantly different from the behavior observed in the laboratory experiments because it is known that the breakup length exhibits a histerisis behavior between zero and unity Weber number. It is revealed that the histerisis behavior is caused by the effect of gravity. The mechanism how the breakup length is determined is also established on the basis of our proposed atomization theory.
