Abstract
A laser doppler anemometer (LDA) was used to measure local dispersion coefficients of particles in turbulent flow. The experimental set-up is described along with the data acquisition equipment and processing procedures. Results for 5 μ particles dispersing from a point source in pipe flow are shown. A second estimate for the diffusivity was obtained from mean square dispersion measurements.
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Abbreviations
- A :
-
projected area of LDA measuring volume, normal to pipe axis
- B 0 − B 2 :
-
coefficients used in concentration curve fits
- C :
-
particle number density, concentration
- d f :
-
fringe spacing
- f B :
-
Bragg cell frequency shift
- f D :
-
frequency of Doppler signal
- H :
-
LDA measuring volume dimension in pipe axial direction
- h :
-
random variation in H
- J :
-
particle flux
- J 0, J 1 :
-
bessel function of zeroth and first order
- r :
-
radial location
- t :
-
time
- U :
-
axial velocity
- u :
-
fluctuating component of axial velocity
- vp :
-
average particle radial velocity
- x :
-
axial coordinate
- y :
-
position of particle in the direction normal to the mean flow relative to the centerline
- \(\overline {y^2 } \) :
-
mean square dispersion
- β2,3 :
-
roots of Bessel functions
- ε p :
-
turbulent diffusivity of particles
- λ:
-
laser wave length
- θ:
-
laser beam intersection angle
References
Arnason, G. 1982: Measurement of particle dispersion in turbulent pipe flow. Ph.D. diss., Pullman, Washington State University
Barnard, B. J. S.; Binnie, A. M. 1962: The vertical diffusivity and mean velocity of particles in a horizontal water pipe. J. Fluid Mech. 15, 35–48
Buchhave, P. 1979: The measurements of turbulence with the burst-type laser Doppler anemometer-errors and correction methods. Ph.D. diss., Buffalo, State University of New York
Durst, F.; Melling, A.; Whitelaw, J. H. 1976: Principles and Practice of Laser-Doppler anemometry. New York: Academic Press
Goldschmidt, V.; Eskinazi, S. 1966: Two-phase flow in a plane jet. J. Appl. Mech. Dec., 735–747
Hedman, P. O.; Smoot, L. D. 1975: Particle-gas dispersion effects in confined coaxial jets. AIChE 121(2), 372–279
Hinze, J.O. 1975: Turbulence. New York: McGraw-Hill
Laufer, J. 1954: The structure of turbulence in fully developed pipe flow. Report NACA-TR-1174
Stock, D. E.; Fadeff, K. G. 1981: Measuring particle transverse velocity using an LDA. Measurement in Polyphase Flow -1982, ASME, ed. Heidrick and Patel, 87–90
Travis, J. R.; Buhr, H. D.; Sesonske, A. 1971: A model for velocity and eddy diffusivity distributions in fully turbulent pipe flow. Can. J. Chem. Eng. 19, 14–18
Wells, M. R. 1982: The effects of crossing trajectories on the diffusion of particles in a turbulent fluid. Ph.D. diss., Pullman, Washington State University
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Arnason, G., Stock, D.E. A new method to measure particle turbulent dispersion using laser doppler anemometer. Experiments in Fluids 2, 89–93 (1984). https://doi.org/10.1007/BF00261327
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DOI: https://doi.org/10.1007/BF00261327