- Volume 14 Issue 4
Optical tomography was used to measure the pattern of spray cross-section. The maximum-likelihood estimation (MLE) algorithm was used to reconstruct the spray cross-section from the measured transmission rate of the spray. A swirl-type injector was used to form an optically dense spray, and the test was carried out in a high-pressure chamber, to control the pressure condition of the test site. Before the experiment, the reliability of the MLE-based reconstruction algorithm was verified, by comparing it with a conventional filtered back projection reconstruction (FBP) method. The MLE algorithm showed superior reconstruction of the image. In the spray patternation experiment, the results of the optical tomography and optical line patternator, which uses Mie scattering signal information, were compared. While measuring the cross-section of optically dense spray, the intensity of the scattering signal had attenuated to an uncorrectable level, which led to incorrect spray pattern measurement by the optical line patternator. However, reliable results were obtained by optical tomography, under the same condition. Finally, the pattern of the optically dense spray was measured at various chamber pressures, of up to 3 MPa. As the chamber pressure increased, the hollow cone-shaped swirl spray shrank, and the attenuation coefficient value of the inner region increased.
Optical Tomography;Maximum-Likelihood Estimation;Liquid Swirl Spray;Spray Patternation
- Lefebvre, A. H., Atomization and Sprays, Hemisphere, New York, 1989.
- Tate, R., "EQUIPMENT AND DESIGN-Spray Patternation", Industrial & Engineering Chemistry, Vol. 52, No. 10, 1960, pp. 49A-58A. DOI: 10.1021/ie50610a005 https://doi.org/10.1021/ie50610a005
- Strakey, P., Talley, D., and Hutt, J., "Mixing characteristics of coaxial injectors at high gas/liquid momentum ratios", Journal of Propulsion and Power, Vol. 17, No. 2, 2001, pp. 402-410. DOI: 0.2514/2.5756 https://doi.org/10.2514/2.5756
- Ruff, G. A., and Faeth, G. M., "Nonintrusive measurement of the structure of dens sprays", Recent advances in spray combustion: spray atomization and drop burning phenomena. Vol. I, edited by K K. Kuo, Progress in Astronautics and Aeronautics, AIAA, Virginia, 1996, pp. 263-296.
- Linne, M. A., Paciaroni, M., Gord, J. R., and Meyer, T. R., "Ballistic imaging of the liquid core for a steady jet in crossflow", Applied optics, Vol. 44, No. 31, 2005, pp. 6627-6634. DOI: 10.1364/AO.44.006627 https://doi.org/10.1364/AO.44.006627
- Talley, D. G., Verdieck, J., Lee, S., McDonell, V., and Samuelsen, G., "Accounting for laser sheet extinction in applying PLLIF to sprays", 34th Aerospace Sciences Meeting and Exhibit, Reno, NY, Jan 15-18, 1996.
- Brown, C., McDonnell, V., and Talley, D., "Accounting for laser extinction, signal attenuation, and secondary emission while performing optical patternation in a single plane", ILASS-Americas 15th Annual Conference on Liquid Atomization and Spray Systems, Madison, WI, May 14-17, 2002.
- Abu-Gharbieh, R., Persson, J. L., Forsth, M., Rosen, A., Karlstrom, A., and Gustavsson, T., "Compensation method for attenuated planar laser images of optically dense sprays", Applied Optics, Vol. 39, No. 8, 2000, pp. 1260-1267. DOI: 10.1364/AO.39.001260 https://doi.org/10.1364/AO.39.001260
- Koh, H., Jung, K., Yoon, Y., Lee, K., and Jeong, K.-S., "Development of quantitative measurement of fuel mass distribution using planar imaging technique", Journal of visualization, Vol. 9, No. 2, 2006, pp. 161-170. https://doi.org/10.1007/BF03181759
- Koh, H., Kim, D., Shin, S., and Yoon, Y., "Spray characterization in high pressure environment using optical line patternator", Measurement Science and Technology, Vol. 17, No. 8, 2006, p. 2159-2167. DOI: 10.1088/0957-0233/17/8/015 https://doi.org/10.1088/0957-0233/17/8/015
- Ramachandran, G., and Lakshminarayanan, A., "Three-dimensional reconstruction from radiographs and electron micrographs: application of convolutions instead of Fourier transforms", Proceedings of the National Academy of Sciences of the United States of America, Vol. 68, No. 9, 1971, pp. 2236-2240. DOI: 10.1073/pnas.68.9.2236 https://doi.org/10.1073/pnas.68.9.2236
- Santoro, R., Semerjian, H., Emmerman, P., and Goulard, R., "Optical tomography for flow field diagnostics", International Journal of Heat and Mass Transfer, Vol. 24, No. 7, 1981, pp. 1139-1150. DOI: 10.1016/0017-9310(81)90163-0 https://doi.org/10.1016/0017-9310(81)90163-0
- Lim, J., Sivathanu, Y. R., Narayanan, V., and Chang, S., "Optical patternation of a water spray using statistical extinction tomography", Atomization and Sprays, Vol. 13, No. 1, 2003, pp. 27-43. DOI: 10.1615/AtomizSpr.v13.i1.20 https://doi.org/10.1615/AtomizSpr.v13.i1.20
- Parrish, S., Zink, R., Sivathanu, Y., and Lim, J., "Spray patternation of a multi-hole injector utilizing planar line-ofsight extinction tomography," ILASS-Americas 22nd Annual Conference on Liquid Atomization and Spray Systems, Cincinnati, Oh, May 16-19, 2010.
- Shepp, L. A., and Vardi, Y., "Maximum likelihood reconstruction for emission tomography", Medical Imaging, IEEE Transactions on, Vol. 1, No. 2, 1982, pp. 113-122. DOI: 10.1109/TMI.1982.4307558 https://doi.org/10.1109/TMI.1982.4307558
- Vardi, Y., and Lee, D., "From image deblurring to optimal investments: Maximum likelihood solutions for positive linear inverse problems", Journal of the Royal Statistical Society. Series B (Methodological), Vol. 55, No. 3, 1993, pp. 569-612.
- Anderson, G. L., and Peleg, K., "Quantification and reduction of erroneous differences between images in remote sensing", Environmental and Ecological Statistics, Vol. 14, No. 2, 2007, pp. 113-127. DOI: 10.1007/s10651-007-0013-4 https://doi.org/10.1007/s10651-007-0013-4
- Chen, S., Lefebvre, A., and Rollbuhler, J., "Factors influencing the circumferential liquid distribution from pressure-swirl atomizers", Journal of engineering for gas turbines and power, Vol. 115, No. 3, 1993, pp. 447-452. DOI: 10.1115/1.2906729 https://doi.org/10.1115/1.2906729
연구 과제 주관 기관 : National Research Foundation