Pages 65-66
This paper presents the possibility to improve atomization of a high-speed liquid jet by utilizing the effect of wall impingement and its mechanism. A simple nozzle with the diameter of 0.3 mm and the L/D ratio of 4 was used to inject water into atmospheric condition with the injection velocity up to 300 m/s. The liquid column was impinged on the end of stainless cylinders with the diameter of 1,3 and 10 mm. Sauter mean diameter (SMD) was measured by narrow-angle forward-scattering technique, and the liquid film velocity was measured by a phase Doppler anemometry. SMD produced by wall impingement was much less than that of free jet. Thus it was shown that wall impingement is effective to promote liquid atomization. It was further shown that SMD of wall impingement is determined by only the liquid film velocity and the impingement angle. The dependence of SMD on the liquid film velocity was compared with that of free jet and the atomization mechanism was discussed on the basis of these characteristic features.
