BREAKUP OF AERATED-LIQUID JETS IN SUPERSONIC CROSSFLOWS

An experimental investigation of the primary breakup of aerated-liquid jets (in the annular flow regime) in supersonic crossflow is described. Single-and double-pulsed shadowgraphy and holography were used to study properties of the liquid sheet as well as outcomes of breakup in the dense spray region near the liquid jet itself that has been inaccessible to past studies using phase Doppler particle analyzers. The results show that the underexpanded internal gas phase forces the liquid sheet into a conical shape upon ejecting from the nozzle exit. Surface breakup along both the downstream and the upstream sides of the jet as well as increased breakup times of the liquid core as compared with pure-liquid jets in subsonic crossflows suggest weak aerodynamic effects of the crossflow near the jet exit. Surface velocities of the liquid sheet were measured and used to develop correlations for the liquid sheet thickness. Sizes of ligaments and drops were measured along the liquid surface and were found to have constant diameters o