Direct Measurement of Turbulence Structures in Mixing Jar Using PIV
Publication: Journal of Environmental Engineering
Volume 123, Issue 2
Abstract
Particle image velocimetry (PIV) is used to measure two-dimensional velocity fields in a standard jar test tank for different impeller speeds. General flow patterns are obtained for the whole tank, and small scale (∼1 cm2) measurements taken at different locations within the jar demonstrate spatial variations of flow characteristics, such as vortex motions near the impeller. Techniques are also developed to derive turbulence dissipation rate and energy intensity as well as local velocity gradient and Kolmogorov microscale for raw PIV data. The results exhibit a consistent general trend with different impeller speeds; for instance, turbulence energy varies directly with mixing intensity. The two-dimensional turbulence field is revealed by using a spatial filtering technique that facilitates calculation of the integral length scale. PIV data are also used to calculate vorticity, which cannot be obtained by more traditional measurement techniques, such as laser-Doppler velocimetry. Overall, PIV represents a significant advance in our ability to characterize the mixing inside a jar test tank.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Adamczyk, A. A., and Rimai, L.(1988). “Reconstruction of a 3-dimensional flow field from orthogonal views of seed tracking video images.”Experiments in Fluids, 6, 380–386.
2.
Adrian, R. J.(1986). “Multi-point optical measurements of simultaneous vectors in unsteady flow—a review.”Int. J. Heat and Fluid Flow, 7(2), 127–145.
3.
Batchelor, G. K. (1953). The theory of homogeneous turbulence. Cambridge University Press, New York, N.Y.
4.
Camp, T. R., and Stein, P. C.(1943). “Velocity gradient and internal work in fluid motion.”J. Boston Soc. of Civ. Engrs., 30(4), 219–237.
5.
Chen, R. C., and Fan, L. S.(1992). “Particle image velocimetry for characterizing the flow structure in three-dimensional gas-liquid fluidized beds.”Chemical Engrg. Sci., 47(13/14), 3615–3622.
6.
Clark, M. M.(1985). “Critique of Camp and Stein's RMS velocity gradient.”J. Envir. Engrg., ASCE, 111(6), 741–754.
7.
Cleasby, J. L.(1984). “Is velocity gradient a valid turbulent flocculation parameter?”J. Envir. Engrg., ASCE, 110(5), 875–897.
8.
Gonzalez, R. C., and Woods, R. E. (1992). Digital image processing. Addison-Wesley Publishing Co., Reading, Mass.
9.
Han, M., and Lawler, D. F.(1992). “The (relative) insignificance of G in flocculation.”J. AWWA, 84(10), 79–91.
10.
Hannoun, I. A., and List, E. J.(1988). “Turbulent mixing at a shear-free density in interface.”J. Fluid Mech., Cambridge, U.K., 189, 211–234.
11.
Hinze, J. O. (1959). Turbulence. McGraw-Hill Book Co., Inc., New York, N.Y.
12.
Hudson, H. E. (1981). Water clarification processes, practical design and evaluation. Van Nostrand Reinhold, New York, N.Y.
13.
Kao, S. V., and Mason, S. G.(1975). “Dispersion of particles by shear.”Nature, 253, 619–621.
14.
Liu, Z.-C., Landreth, C. C., Adrian, R. J., and Hanratty, T. J.(1991). “High resolution measurement of turbulent structure in a channel with particle image velocimetry.”Experiments in Fluids, 10, 301–312.
15.
McConnachie, G. L.(1991). “Turbulence intensity of mixing in relation to flocculation.”J. Envir. Engrg., ASCE, 117(6), 731–750.
16.
Nezu, I., Nakagagwa, H., and Saeki, K. I. (1994). “Coherent structures in compound open-channel flows by making use of particle-tracking visualization technique.”Proc., 1994 ASCE Hydr. Engrg. Conf., ASCE, New York, N.Y., 406–415.
17.
Patterson, G. K., and Zipp, R. P. (1991). “Turbulence and mixing: modeling effects on chemical reactions.”Mixing in coagulation and flocculation, A. Amirtharajah, M. M. Clark, and R. R. Trussel, eds., American Water Works Research Foundation, Denver, Colo.
18.
Press, W. H., Flannery, B. P., and Piersol, G. (1986). Numerical recipe: the art of scientific computing. Cambridge University Press, New York, N.Y.
19.
Reuss, D. L., Adrian, R. J., Landreth, C. C., French, D. T., and Fansler, T. D. (1989). “Instantaneous planar measurements of velocity and large-scale vorticity and strain rate in an engine using particle-image velocimetry.”SAE Tech. Paper Ser. 890616, SAE Publications Group, Warrendale, Pa.
20.
Reuss, D. L., Bardsley, M., Felton, P. G., Landreth, C. C., and Adrian, R. J. (1992). “Velocity, vorticity, and strain rate ahead of a flame measured in an engine using particle image velocimetry.”SAE Tech. Paper Ser. 900053, SAE Publications Group, Warrendale, Pa.
21.
Stanley, S. J., and Smith, D. W. (1995). “Measurement of turbulent flow in standard jar test apparatus.”J. Envir. Engrg., ASCE, 121(12), 902–910.
22.
Tambo, N., and Hozumi, H.(1979). “Physical characteristics of flocs-II. strength of floc.”Water Res., 13, 421–427.
23.
Tennekes, H., and Lumley, J. L. (1972). A first course in turbulence. MIT Press, Cambridge, Mass.
24.
Wu, H., and Patterson, G. K.(1989). “Laser-doppler measurement of turbulent-flow parameters in a stirred mixer.”Chemical Engrg. Sci., 44(10), 2207–2221.
Information & Authors
Information
Published In
Journal of Environmental Engineering
Volume 123 • Issue 2 • February 1997
Pages: 115 - 125
Copyright
Copyright © 1997 American Society of Civil Engineers.
History
Published online: Feb 1, 1997
Published in print: Feb 1997
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.