A Comparative Study Between Light Extinction and Direct Sampling Methods for Measuring Volume Fractions of Twin-Hole Sprays Using Tomographic Reconstruction

  • Lee, Choong-Hoon (Department of Automotive Engineering, Seoul National University of Technology)
  • Published : 2003.12.01

Abstract

The spatially resolved spray volume fractions from both line-of-sight data of direct measuring cells and a laser diffraction particle analyzer (LDPA) are tomographically reconstructed by the Convolution Fourier transformation, respectively. Asymmetric sprays generated from a twin-hole injector are tested with 12 equiangular projections of measurements. For each projection angle, a line-of-sight integrated injection rate was measured using a direct sampling method and also a liquid volume fraction from a set of line-of-sight Fraunhofer diffraction measurements was measured using a light extinction method. Interpolated data between the projection angles effectively increase the number of projections, significantly enhancing the signal-to-noise level in the reconstructed data. The reconstructed volume fractions from the direct sampling cells were used as reference data for evaluating the accuracy of the volume fractions from the LDPA.

Keywords

References

  1. Cha, S. S. and Sun, H., 1990, 'Tomography for Reconstructing Continuous Fields from ill-Posed Multidirectional Interferometric Data,' Applied Optics, Vol. 29, No.2, pp.251-258 https://doi.org/10.1364/AO.29.000251
  2. Cha, D. J. and Cha, S. S., 1996, 'Holographic Interferometric Tomography for Limited Data Reconstruction,' AIAA Journal, Vol. 34, No.5, pp. 1019-1026 https://doi.org/10.2514/3.13182
  3. Cormack, A. M., 1963, 'Representation of a Function by its Line Integrals, with Some Ra-diological Applications,' J. Appl. Phys., Vol. 34, pp.2722-2727 https://doi.org/10.1063/1.1729798
  4. Cormack, A. M., 1973, 'Reconstruction of Densities from Their Projections with Application in Radiology Physics,' J. Phys. Assoc., Vol. 6, pp.361-369
  5. Dodge, L. G., Rhodes, D. J. and Reitz, R. D., 1987, 'Drop-size Measurement Techniques for Sprays: Comparison of Malvern Laser-Diffraction and Aerometrics Phase/Doppler,' Applied Optics, Vol. 26, No. 11, pp. 2144-2154 https://doi.org/10.1364/AO.26.002144
  6. Eckbreath, A. C., 1987, Laser Diagnostics for Combustion Temperature and Species, pp. 362-401
  7. Gordon, R. G., Herman, G. T. and Johnson, S. A., 1975, 'Imaging Reconstruction from Projections,' Sci. Am., Vol. 233, pp. 56-68
  8. Goulard, R. and Emmerman, P. J., 1980, 'Combustion Diagnostics by Multianular Scanning,' Inverse Scattering Problems in Optics, Springer Verlag, Berlin, pp. 215-235
  9. Jeong, S. J. and Lee, S. Y., 1992, 'Experimental Study on the Flow Characteristics of a Confined Spray,' Transactions of KSME, Vol. 16, No.5, pp. 1011-1018
  10. Kak, A. C. and Slaney, M., 1988, Principles of Computerized Tomographic Imaging, IEEE Press, New York
  11. Lee, C. H. and Chung, S. H., 1997, 'Tomographic Reconstruction of Asymmetric Spays from a Twin-Hole Air Shroud Injector,' Atomization and Sprays, Vol. 7, No.1, pp. 184-197
  12. Malvern Instruments Ltd., 1991, Malvern System, 2600 Instruction Manual
  13. Rowely, P. D., 1969, 'Quantitative Interpretation of Three-Dimesional Weakly Refractive Phase Objects Using Holographic Interfermetry,' J. Opt. Soc. Am., Vol. 59, p. 1496 https://doi.org/10.1364/JOSA.59.001496
  14. Santro, R. J, Semerjian, H. G., Emmerman, P. J. and Goulard, R., 1981, 'Optical Tomography for flow Field Diagnostics,' International Journal of Heat and Mass Transfer, Vol. 24, No.7, pp. 1139-1150 https://doi.org/10.1016/0017-9310(81)90163-0
  15. Shepp, L. A. and Logan, B. F., 1974, 'Reconstructing Interior Head Tissue from X-ray Transmissions,' IEEE Trans., Vol. NS-21, pp.228-236
  16. Slepicka, J. S. and Cha, S. S., 1997, 'Three Dimensional flow Diagnostics by Holographic Diffraction Image Velocimetry,' Proceedings of optical technology in fluid, thermal, and combustion flow III, SPIE- The International Society for Optical Engineering, Vol. 3172, pp.2226-232 https://doi.org/10.1117/12.293397
  17. Swenny, D. W. and Vest, C. M., 1973, 'Reconstruction of Three Dimensional Refractive Index Fields from Multidirectional Interferometric Data,' Applied Optics, Vol. 12, pp. 2649-2664 https://doi.org/10.1364/AO.12.002649
  18. Yang, S. Y., Lee, C. H., Koo, J. A. and Chung, S. H., 1999, 'An Experimental Study of Reconstruction from Laser Diffraction Measurement for Axisymmetric Sprays,' Transactions of the Korean Society of Automotive Engineers, Vol. 8, No. 1, pp. 10-16
  19. Yule, A. J., Ah Seng, C., Felton, P. G., Ungot, A. and Chigier, N. A., 1981, 'A Laser Tomographic Investigation of Liquid Fuel Sprays,' Proc. Combust. Inst. The Combustion Institute, Vol. 18, pp. 1501-1510
  20. Zhu, H. M., Sun, T. Y. and Chigier, N., 1987, 'Tomographic Transformation of Malvern Spray Measurements,' Atomization and Sprays, Vol. 3, pp.89-105