Atomization and Sprays, 21 (3): 203–219 (2011) CHARACTERIZATION OF TRAJECTORY, BREAK POINT, AND BREAK POINT DYNAMICS OF A PLAIN LIQUID JET IN A CROSSFLOW Q. Wang, U. M. Mondragon, C. T. Brown, & V. G. McDonell * Energy Research Consultants, 23342 South Pointe Drive, Suite E, Laguna Hills, California 92653-1422, USA * Address all correspondence to V. G. McDonell E-mail: mcdonell@erc-ltd.com Original Manuscript Submitted: 30/11/2010; Final Draft Received: 21/06/2011 The injection of a plain liquid jet into a gaseous crossflow has been studied extensively. Empirical models describing the aspects of the breakup, penetration, and dispersion of the liquid jet have been developed based on experimental data. In recent years, however, more sophisticated simulation approaches such as surface-tracking methods have evolved, and as a result, a richer database for assessing accuracy is of great interest. In parallel, advancements in imaging diagnostics that can capture details regarding the breakup processes have occurred, creating an opportunity to provide new types of results that can be used for model validation. While imaging methods are convenient to apply, extraction of the necessary quantitative information to compare directly with advanced simulation methods requires considerable effort. Due to the vast amounts of data that can be generated in a matter of seconds, manual analysis of the images obtained can be tedious. As a result, automated methodologies for extracting this information are necessary. The present work describes the application of automated processing routines to the breakup of a plain liquid jet in a crossflow under varying conditions. The results extracted are used to generate correlations for column break point time, trajectory, and the dynamics of the breakup and liquid column characteristics. The correlations are compared with prior expressions generally derived from much smaller datasets and found to exhibit some significant differences, particularly with respect to the break time. These expressions can be incorporated into atomization models within computational fluid dynamics packages or as part of a standalone atomization model. KEY WORDS: liquid jet, atomization, crossflow, correlation, fuel, image analysis, high speed video, trajec- tory, dynamic breakup 1. BACKGROUND AND OBJECTIVE The modeling of liquid jet injection into a gaseous cross- flow has been progressively studied beginning with pre- diction of averaged far-field spray characteristics and building up to predictions of more complex phenomena relating to the near field and the liquid column (Kush and Schetz, 1975; Heister et al., 1989; Brown and McDonell, 2006; Madabhushi, 2003). With increasing modeling fo- cus on the liquid column, new measurement systems and analysis are required to produce data sets for model de- velopment and validation. Recently, high-speed video has become a common data acquisition system for recording the behavior of the liquid column, but often the processing of these video yields only interpreted or qualitative results. To address this shortcoming, automated quantitative processing soft- ware tools are of increasing interest. In the present work automated tools have been developed and applied to the analysis of the liquid column (1) break point and time, (2) trajectory, and (3) instabilities. For jets in a crossflow, the break time of the liquid col- umn is often chosen as a primary characteristic over other possible choices such as the length or streamwise loca- 1044–5110/11/$35.00 c  2011 by Begell House, Inc. 203