Temperature fields in turbulent dilute spray flames are investigated – for the first time - using chirped-probe-pulse (CPP) femtosecond (fs) coherent anti-Stokes Raman spectroscopy (CARS) at a repetition rate of 5kHz. This ultrafast technique is applied to the Sydney Needle Spray Burner (SYNSBURNTM) featuring air-blast atomization of a liquid jet issued from a needle that can be translated within a coflowing air stream. This burner allows direct control of the spray inlet condition for a fixed mass loading, thus regulating spray inhomogeneity between the two extremes of dilute and dense. Various dilute spray flames of acetone for a fixed recess length of 80mm are investigated at different global Weber number or bulk jet Reynolds number. Comparison of mean temperature profiles with thermocouple measurements show very good agreement. In addition, the high data rate of 5kHz provides temporally resolved information about the dynamics of fluid structures in the main jet/pilot and pilot/coflow shear layers. These high bandwidth temperature measurements will aid in turbulent combustion model validation and provide insight to spatio-temporal instabilities in practical combustion devices such as gas turbine combustors and augmentors.
|Original language||English (US)|
|Title of host publication||11th Asia-Pacific Conference on Combustion, ASPACC 2017|
|State||Published - Jan 1 2017|
Bibliographical noteKAUST Repository Item: Exported on 2022-06-28
Acknowledged KAUST grant number(s): 1975-01
Acknowledgements: The Sydney group is supported by the Australian Research Council. The Purdue group is supported by the U.S. Department of Energy, Division of Chemical Sciences, Geosciences and Biosciences under Grant No. DE-FG02-03ER15391 and by the King Abdullah University of Science and Technology under CCF sub- award No. 1975-01.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.