Accuracy of Particle Flux and Volume Fraction Measurement by Shadow Doppler Velocimetry

  • H. Morikita
  • Ilias Prassas
  • A. M. K. P. Taylor
Conference paper


This paper reports on the accuracy of measurement of volume fraction and flux of a dispersed phase by Shadow Doppler Velocimetry (SDV). The SDV is an imaging technique, based on a conventional laser Doppler velocimeter and a linear photodiode array, for simultaneous particle- size and velocity measurement. The SDV also provides a measurement of the spatial position of a particle as it travels through the probe volume; as a result, it is not necessary to establish the dependence of the cross-sectional area of the probe volume on particle size for flux and volume fraction measurements. Instead, this area is defined by the operator of the instrument and is independent of the irradiance distribution of the incident laser beams, unlike — for example — phase Doppler anemometry (PDA). The accuracy of the flux measurement has been assessed from integration of flux and volume fraction measurements across a fully developed 20x20 mm turbulent water channel flow flowing at 0.16 m/s, laden with a known fraction of quasi-neutrally buoyant polyethylene spheres of nominal mean diameter of 100 μm, and the random uncertainty in the derived particle volume fraction was no more than 20% for particle volume fractions up to 0.005% and typically 10%. The integration procedure contributed a random uncertainty of less than 12%, the determination of particle volume a systematic uncertainty of 6% and the determination of the area of the sampling-space a further 8% systematic uncertainty, whereas the random uncertainty in determining the area of the sampling-space was estimated to be approximately 10%. For particle volume fraction larger than 0.005% and up to 0.05%, signal identification was affected by turbidity and multiple occupancy effects and thus the SDV measurement was compensated by the signal error rate, resulting in a particle volume fraction accurate to better than 40%.


Shadow Doppler Velocimetry Flux and volume fraction measurement Irregular particles 


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  1. Capp, S. P.: Experimental investigation of the turbulent axisymmetric jet, PhD thesis, State University of New York at Buffalo, 1983.Google Scholar
  2. Grehan, G., Gouesbet, G., Naqwi, A. and Durst, F., 1992, Trajectory ambiguities in phase Doppler systems: use of polarizers and additional detectors to suppress the effect, Proceedings of 6th international symposium on Application of Laser Techniques to Fluid Mechanics, Lisbon, Portugal, paper 12.1.Google Scholar
  3. Hardalupas, Y. and Taylor, A. M. K. P., 1989, On the measurement of particle concentration near a stagnation point, Exp. Fluids, Vol 8, pp. 113–118.CrossRefGoogle Scholar
  4. Hardalupas, Y., Hishida K., Maeda M., Morikita, H., Taylor A. M. K. P. and Whitelaw, J. H., 1994, Shadow Doppler Technique for Sizing Particles of Arbitrary Shape, Appl. Optics, Vol. 33, No. 36, pp. 8417–8426.ADSCrossRefGoogle Scholar
  5. Hardalupas, Y., Taylor A. M. K. P. and Whitelaw, J. H., 1994, Mass flux, mass fraction and concentration measurement of liquid fuel in a swirl-stabilised flame, Int. J. Multiphase flow, Vol. 20, pp. 233–259.CrossRefzbMATHGoogle Scholar
  6. Hirleman, E. D. and Moon, H. K., 1982, Response Characteristics of the Multiple-Ratio Single-Particle Counter, J. of Colloid and Interface Sci, Vol. 87, No. 1 pp. 124–139.CrossRefGoogle Scholar
  7. Hishida, K., Maeda, M., Morikita, H., Taylor, A. M. K. P. and Whitelaw, J. H., 1995, Particle sizing in a confined reacting flow using Shadow Doppler Anemometry, 4th Int. Congr. on Optical Particle Sizing, Nürnberg, Germany.Google Scholar
  8. Hovenac, E. A. and Hirleman, E. D., 1991, Use of Pinholes and Reticles for Calibration of Cloud Droplet Instrumentation, J. of Oceanic Tech., Vol. 8, No. 1, pp. 166–171.CrossRefGoogle Scholar
  9. Ibrahim, K. M., Werthimer, G. D. and Bachalo, W. D., 1990, Signal processing considerations for laser Doppler and phase Doppler applications, Applications of Laser Techniques to Fluid Mechanics, Springer-Verlag, pp. 291, 316.Google Scholar
  10. Kobashi, K., Hishida, H. and Maeda, M., 1990, Measurement of fuel injector spray flow of I.C. engine by FFT based phase Doppler anemometer- an approach to the time series measurement of size and velocity, Applications of Laser Techniques to Fluid Mechanics, Springer-Verlag, pp. 268, 287.Google Scholar
  11. Maeda, M., Morikita, H., Prassas, I., Taylor, A. M. K. P. and Whitelaw, J. H., 1995, Size and Velocity Measurement by Shadow Doppler Velocimetry within a Pulverised Coal-Fired Furnace, HTD-Vol. 321/FED-Vol. 233, pp.351–360.Google Scholar
  12. Maeda, T., Morikita, H., Hishida, K. and Maeda, M.:, 1996, Determination of effective measurement area in a conventional phase-Doppler anemometry, 8th Int. Symp. on applications of laser techniques to fluid mechanics, Lisbon.Google Scholar
  13. Morikita, H., 1995, personal communication.Google Scholar
  14. Morikita, H., Hishida, K. and Maeda, M., 1995, Measurement of Size and Velocity of Arbitrarily Shaped Particles by LDA Based Shadow Image Technique, Developments in Laser Techniques and Applications to Fluid Mechanics, Springer-Verlag, pp. 354–375.Google Scholar
  15. Morikita, H., Hishida, K. and Maeda, M., 1994, Simultaneous Measurement of Velocity and Equivalent Diameter of Non-spherical Particles, Part. Part. Syst. Charact., Vol. 11, No. 3, pp. 227–234.CrossRefGoogle Scholar
  16. Orfanoudakis, N. G. and Taylor, A. M. K. P., 1992, The effect of particle shape on the amplitude of scattered light for a sizing instrument, Part. Part. Syst. Charact., Vol. 9, pp. 223–230.CrossRefGoogle Scholar
  17. Orfanoudakis, N. G., 1994, Measurements of size and velocity of burning coal, PhD Thesis, Univ. of London.Google Scholar
  18. Orfanoudakis, N. G. and Taylor, A. M. K. P., 1995, Evaluation of an amplitude sizing anemometer and application to a pulverised coal burner. Comb. Sci. and Tech., Vol. 108, pp. 255–277.CrossRefGoogle Scholar
  19. Qiu, H. H. & Sommerfeld, M., 1992, A reliable method for determine the measurement volume size and particle mass fluxes using phase-Doppler anemometry, Exp. Fluids, 13, pp. 393–404.CrossRefGoogle Scholar
  20. Saffman, M., 1987, Automatic calibration of LDA measurement volume size, Appl. Optics, Vol. 26, No. 13, pp. 2592.ADSCrossRefGoogle Scholar
  21. Sankar, S. V. and Bachalo, W. D., 1991, Response characteristics of the phase Doppler particle analyser for sizing spherical particles larger than the light wavelength, Appl. Optics, Vol. 30, No. 12, pp. 1487–1496.ADSCrossRefGoogle Scholar
  22. Sommerfeld, M. and Qiu, H.-H., 1995, Particle concentration measurement by phase Doppler anemometry in complex dispersed two-phase flows, Exp. Fluids, 18, pp. 187–198.CrossRefGoogle Scholar
  23. Schöne, F., Bauckhage, K. and Wriedt, T., 1994, ″Size of the detection area of a phase-Doppler anemometer for Reflecting and Refracting particles″, Part. Part. Syst. Charact., 11, 1994, pp. 327–338.CrossRefGoogle Scholar
  24. Taylor, A. M. K. P., 1995, Experimental techniques for dispersed two phase flows, Annual ASME/JSME Fluid Eng. Meeting, Hilton Head, SC, USA.Google Scholar
  25. Yeoman, M. L., Azzopardi, B. J., White, H. J., Bates, C. J. and Roberts, P. J., 1982, Optical development and application of a two colour LDA system for the simultaneous measurement of particle size and particle velocity, Engineering Applications of Laser Velocimetry, Winter Annual Meeting ASME, Phoenix, Arizona.Google Scholar
  26. Xu, T-H and Tropea, C., 1994, Improving the performance of two-component phase Doppler anemometers, Meas. Sci. Technol., Vol. 5, pp. 969–975ADSCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1997

Authors and Affiliations

  • H. Morikita
    • 1
  • Ilias Prassas
    • 2
  • A. M. K. P. Taylor
    • 2
  1. 1.Department of Mechanical EngineeringKeio UniversityKohoku-kuJapan
  2. 2.Imperial College, Department of Mechanical EngineeringLondonUK

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