Experimental Evaluation of the Best Approach for Diesel Spray Images Segmentation

[EN] In this article, two of the most used methods for diesel spray macroscopic characterization are presented; the first one is the likelihood ratio test method (LRT) and the second one is the Otsu's thresholding method (OTM). Both methods are applied to different diesel sprays visualized in a high-pressure nitrogen chamber obtaining better results with the LRT in terms of both contour determination and coherence of the results. Finally, the influence of the algorithm used for the segmentation on the macroscopic characterization measurements is observed. © 2011, Society for Experimental Mechanics.This research has been funded in the frame of the project TRA2010-17564 with title "Estudio teorico experimental de la influencia del combustible sobre la cavitacion y el desarrollo del chorro evaporativo" from the "Ministerio de Ciencia e Innovacion" of Spain.Macian Martinez, V.; Payri, R.; García Martínez, A.; Bardi ., M. (2011). Experimental Evaluation of the Best Approach for Diesel Spray Images Segmentation. Experimental Techniques. 2011:1-9. https://doi.org/10.1111/j.1747-1567.2011.00730.xS192011Desantes, J. M., Payri, R., Pastor, J. M., & Gimeno, J. (2005). EXPERIMENTAL CHARACTERIZATION OF INTERNAL NOZZLE FLOW AND DIESEL SPRAY BEHAVIOR. PART I: NONEVAPORATIVE CONDITIONS. Atomization and Sprays, 15(5), 489-516. doi:10.1615/atomizspr.v15.i5.20Desantes, J. M., Pastor, J. V., Payri, R., & Pastor, J. M. (2005). EXPERIMENTAL CHARACTERIZATION OF INTERNAL NOZZLE FLOW AND DIESEL SPRAY BEHAVIOR. PART II: EVAPORATIVE CONDITIONS. Atomization and Sprays, 15(5), 517-544. doi:10.1615/atomizspr.v15.i5.30Payri, R., Salvador, F. J., Gimeno, J., & de la Morena, J. (2009). Effects of nozzle geometry on direct injection diesel engine combustion process. Applied Thermal Engineering, 29(10), 2051-2060. doi:10.1016/j.applthermaleng.2008.10.009Payri, R., Salvador, F. J., Gimeno, J., & Soare, V. (2005). Determination of diesel sprays characteristics in real engine in-cylinder air density and pressure conditions. Journal of Mechanical Science and Technology, 19(11), 2040-2052. doi:10.1007/bf02916497Zapata , D.L. Caracterización de los procesos de inyección -combustión diesel mediante visualización y procesado digital de imágenes, 2010Sankur, B. (2004). Survey over image thresholding techniques and quantitative performance evaluation. Journal of Electronic Imaging, 13(1), 146. doi:10.1117/1.1631315Pastor, J. V., Arrègle, J., García, J. M., & Zapata, L. D. (2007). Segmentation of diesel spray images with log-likelihood ratio test algorithm for non-Gaussian distributions. Applied Optics, 46(6), 888. doi:10.1364/ao.46.000888Cox, D. R., & Hinkley, D. V. (1974). Theoretical Statistics. doi:10.1007/978-1-4899-2887-0Otsu, N. (1979). A Threshold Selection Method from Gray-Level Histograms. IEEE Transactions on Systems, Man, and Cybernetics, 9(1), 62-66. doi:10.1109/tsmc.1979.4310076Margot , X. Payri , R. Gil , A. Chavez , M. Pinzello , A. Combined CFD-Phenomenologial approach to the Analysis of Diesel Sprays Under Non-Evaporative Conditions, 200