Title

Atomization Experiments in a Coaxial Coflowing Mach 1.5 Flow

Abstract

Extensive flow visualization using schlieren/shadowgraph, flash photography and short duration (ns) laser imaging, and drop size measurements are reported in this work. The supersonic nozzle operating conditions ranged from an overexpanded to highly underexpanded mode. A phenomenon of the liquid jet expanding into a bubblelike formation as it interacts with the first set of waves is explained. Photographic evidence indicated the presence of a primary region enclosed by the first shock cell where the primary breakup occurred, a secondary region enclosing the bubblelike formation, and a third subsonic region further downstream. Atomization seemed to be initiated by the growth of three-dimensional structures on the liquid surface. Subsequent detachment of the three-dimensional structure as fine droplets by the intense shear at the liquid gas interface was observed. This seems to partially confirm the boundary-layer stripping mechanism proposed by Taylor and Ranger and Nicholls.

Department(s)

Mechanical and Aerospace Engineering

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1994 American Institute of Aeronautics and Astronautics (AIAA), All rights reserved.

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