Abstract
Experimental investigations have been carried out for the breakup process of an annular water jet exposed to an inner air stream by videographic and photographic techniques. Three flow regimes for the jet breakup process have been identified, i.e., bubble formation, annular jet formation and atomization. Within the bubble formation regime, the jet breakup characteristics measured from the photographs taken under various liquid and gas velocities indicate that nearly uniform bubbles are observed for various air-to-water velocity ratios; both the jet breakup length and the wavelength for bubble formation decrease as the air-to-water velocity ratio is increased. The measurements are compared with the predictions by the linear instability analysis, and fair agreement is obtained.
