Abstract

Spatially resolved measurements of droplet size and velocity are desirable to aid in matching fuel injectors to combustor flow fields and to support development of two-phase-flow modeling. Interferometric laser-based techniques have been available since the early 1970s. Successful application to practical sprays, however, has been hampered by numerous difficulties. In this paper, two interferometric techniques (visibility/intensity validation and phase/Doppler) are critically examined in characterizing the spray of an air-assist nozzle with Sauter mean diameter < 35 μm. The two techniques are compared to each other and evaluated against a Malvern diffraction unit. With the use of a rotating grating for frequency shifting, the interferometric techniques compare well with each other and to the diffraction method. Due to its broadened size and velocity ranges, the phase/Doppler technique is more easily applied to the spray than is visibility/intensity validation. The consistency of the interferometric results raises questions with regard to the use of Malvern’s most frequently applied distribution model.

© 1987 Optical Society of America

Drop-size measurement techniques for sprays: comparison of Malvern laser-diffraction and Aerometrics phase/Doppler

Lee G. Dodge, Deborah J. Rhodes, and Rolf D. Reitz
Appl. Opt. 26(11) 2144-2154 (1987)

Phase-Doppler interferometry with probe-to-droplet size ratios less than unity. II. Application of the technique

Peter A. Strakey, Douglas G. Talley, Subra V. Sankar, and Will D. Bachalo
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Comparison of performance of drop-sizing instruments

Lee G. Dodge
Appl. Opt. 26(7) 1328-1341 (1987)

Phase-Doppler interferometry with probe-to-droplet size ratios less than unity. I. Trajectory Errors

Peter A. Strakey, Douglas G. Talley, Subra V. Sankar, and Will D. Bachalo
Appl. Opt. 39(22) 3875-3886 (2000)

Interferometric laser imaging for droplet sizing: a method for droplet-size measurement in sparse spray systems

A. R. Glover, S. M. Skippon, and R. D. Boyle
Appl. Opt. 34(36) 8409-8421 (1995)