Turbulence Measurement in Nonuniform Open-Channel Flow Using Acoustic Doppler Velocimeter (ADV)
Publication: Journal of Engineering Mechanics
Volume 127, Issue 3
Abstract
Measurements of the mean and turbulence characteristics in nonuniform open-channel flows were carried out using a 3D acoustic Doppler velocimeter. Both accelerating and decelerating flows were investigated. Analyses based on the Reynolds equation and the continuity equation of 2D open-channel flow show that a flow will be in equilibrium if the pressure-gradient parameter β is a constant at different sections along the flow direction. The experimental data show that all the flows investigated are in equilibrium. The effect of the flow nonuniformity on the mean velocity and turbulence profiles was also examined. The study shows that (1) the log law is still valid for both accelerating and decelerating flows in the inner region. The Coles law can be used for the entire region, but the wake-strength parameter Π depends on the β-value; and (2) the turbulence intensities and the Reynolds stress decrease in accelerating flow and increase in decelerating flow, when compared with those in uniform flow. Finally, using the Reynolds equation and the continuity equation of 2D open-channel flow, the theoretical expressions for the distribution of vertical velocity and the Reynolds stress have been developed. The measured vertical velocity and the Reynolds stress profile compare well with the derived expressions.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Cardoso, A. H., Graf, W. H., and Gust, G. (1991). “Steady gradually accelerating flow in a smooth open channel.”J. Hydr. Res., Delft, The Netherlands, 29(4), 525–543.
2.
Chien, N., and Wan, Z. ( 1985). Mechanics of sediment transport, China Science Press, Beijing.
3.
Graf, W. H., and Song, T. (1995). “Bed-shear stress in nonuniform and unsteady open-channel flows.”J. Hydr. Res., International Association for Hydraulic Research, 33(5), 699–704.
4.
Kironoto, B., and Graf, W. H. ( 1995). “Turbulence characteristics in rough nonuniform open-channel flow.” Proc., Instn. Civ. Engrs. Water, Maritime, and Energy, U.K., Vol. 112, 316–348.
5.
Lovera, F., and Kennedy, J. F. (1969). “Friction factor for flat-bed flows in sand channels.”J. Hydr. Div., ASCE, 95(4), 1227–1234.
6.
Lyn, D. A. (1993). “Turbulence measurements in open-channel flows over artificial bed forms.”J. Hydr. Engrg., ASCE, 119(3), 306–326.
7.
McLean, S. R. ( 1992). “On the calculation of suspended load for noncohesive sediments.” J. Geophys. Res., 97(C4), 5759–5770.
8.
Nezu, I. ( 1977). “Turbulent structure in open-channel flows.” Doctoral dissertation, Kyoto University, Kyoto, Japan.
9.
Nezu, I., Kadota, A., and Nakagawa, H. ( 1994). “Turbulence structure in accelerating and decelerating open-channel flows with laser Doppler anemometers.” Proc., 9th Congr. ADP-IAHR, 413–420.
10.
Rotta, J. C. ( 1962). “Turbulent boundary layer in incompressible flow.” Progress in aeronautical science, Ferri, Kuchman, and Stern, eds., Vol. 2, Pergamon, Tarrytown, N.Y.
11.
Ryckoczi, L. ( 1967). “Experiment study of flume bed roughness.” Proc., Symp. 2nd IAHR, Vol. 1, 181–186.
12.
Song, T. ( 1994). “Velocity and turbulence distribution in nonuniform and unsteady open-channel flow.” Doctoral dissertation, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland.
13.
Song, T., and Graf, W. H. ( 1994). “Nonuniform open-channel flow over a rough bed.” J. Hydroscience and Hydr. Engrg., Japan Society of Civil Engineering, Tokyo, 12(1), 1–25.
14.
Song, T., and Graf, W. H. (1996). “Velocity and turbulence distribution in unsteady open-channel flows.”J. Hydr. Engrg., ASCE, 122(3), 141–154.
15.
Song, T., Graf, W. H., and Lemmin, U. (1994). “Uniform flow in open-channel with movable gravel bed.”J. Hydr. Res., International Association for Hydraulic Research, 32(6), 861–876.
16.
Tang, C. (1963). “Threshold of sediment.”J. Hydr. Engrg., Beijing, 2, 02 (in Chinese).
17.
Tennekes, H., and Lumley, J. L. ( 1972). A first course in turbulence, MIT Press, Cambridge, Mass.
18.
Tsujimoto, T., Saito, A., and Nitta, K. ( 1990). “Open-channel flow with spatial acceleration or deceleration.” KHL Prog. Rep., Hydr. Lab., Kanazawa University, Kanazawa, Japan.
19.
Vanoni, V. A., and Nomicos, G. N. ( 1960). “Resistance properties of sediment-laden streams.” Trans. ASCE, 125, 1140–1175.
20.
van Rijn, L. C. (1984). “Sediment transport, Part II: Suspended load transport.”J. Hydr. Engrg., ASCE, 110(11), 1613–1641.
Information & Authors
Information
Published In
Journal of Engineering Mechanics
Volume 127 • Issue 3 • March 2001
Pages: 219 - 232
History
Received: Jun 12, 1997
Published online: Mar 1, 2001
Published in print: Mar 2001
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.