摘要: Schlieren images were gathered from the side, and spray droplet diameter and velocity distributions were obtained along the centerline of an underexpanded jet as it flowed through shocks and an expansion wave. Schlieren images rev... 展开 Schlieren images were gathered from the side, and spray droplet diameter and velocity distributions were obtained along the centerline of an underexpanded jet as it flowed through shocks and an expansion wave. Schlieren images revealed the location and dimensions of the shock structures, which were then used to determine the locations along the centerline where phase Doppler interferometry measurements were gathered. Schlieren images revealed that, at the liquid flow rates used in this study, there were not dramatic shifts in the compressible flow structures' location or behavior. Liquid spray at the periphery of the jet, produced by the un-entrained liquid film at the nozzle's inside surface that was sheared by the jet's gas flow, was visible in the schlieren images but was not measured in this study. Droplet velocity measurements indicated some of the expected gas velocity behavior: increasing velocity up to the shock then decreasing velocity in the following compressed region. Downstream of the expansion wave, the droplets did not immediately accelerate. Droplet diameter statistics, used to calculate Dio and D32, appeared to suggest both droplet fragmentation and agglomeration as the spray was carried through the abrupt velocity changes at shocks and expansion waves. The differences in Dm and D.u suggest that more careful examination of the droplet diameter probability statistics and shadow microscopy of the spray along the axis of the jet will provide greater clarity of how the spray and shock structures are interacting. 收起