New Method for Estimation of Discharge
Publication: Journal of Hydraulic Engineering
Volume 132, Issue 10
Abstract
A new technique for drawing isovel patterns in an open or closed channel is presented. It is assumed that the velocity at each arbitrary point in the conduit is affected by the hydraulic characteristics of the boundary. While any velocity profile can be applied to the model, a power-law formula is used here. In addition to the isovels patterns, the energy and momentum correction factors ( and ), the ratio of mean to maximum velocity , and the position of the maximum velocity are calculated. To examine the results obtained, the model was applied to a pipe with a circular cross section. A comparison between the profiles of the proposed model and the available power-law profile indicated that the two profiles were coincident with each other over the majority of the cross section. Furthermore, the predicted isovels were compared with velocity measurements in the main flow direction obtained along the centerline and lateral direction of a rectangular flume. The estimated discharge, based on measured points on the upper half of the flow depth away from the boundaries was within of the measured and much better in comparison to the prediction of one- and two-point methods. The prediction of the depth-averaged velocity values for the River Severn in the United Kingdom shows a good agreement with the measured data and the best analytical results obtained by the depth-averaged Navier–Stokes equations.
Get full access to this article
View all available purchase options and get full access to this article.
References
Babaeyan-Koopai, K., Ervine, D. A., Carling, P. A., and Cao, Z. (2002). “Velocity and turbulence measurements for two overbank flow events in River Severn.” J. Hydraul. Eng., 128(10), 697–705.
Berlamont, J. E., Trouw, K., and Luyckx, G. (2003). “Shear stress distribution in partially filled pipes.” J. Hydraul. Eng., 129(9), 891–900.
Brownlie, W. (1983). “Flow depth in sand-bed channels.” J. Hydraul. Eng., 109(7), 959–990.
Carollo, F. G., Ferro, V., and Termini, D. (2002). “Flow velocity measurements in vegetated channels.” J. Hydraul. Eng., 128(7), 669–673.
Chadwick, A. J., and Morfett, J. C. (1993). Hydraulics in civil and environmental engineering, Chapman and Hall, London.
Chaudhry, M. H. (1993). Open-channel flow, Prentice-Hall, Englewood Cliffs, N.J.
Chen, C. L. (1991a). “Power-law of flow resistance in open channel: Manning formula revisited.” Centennial of Manning’s formula, Water Research, Charlottesville, Va., 206–240.
Chen, C. L. (1991b). “Unified theory on power laws for flow resistance.” J. Hydraul. Eng., 117(3), 371–389.
Chen, X., and Chiew, Y. M. (2003). “Response of velocity and turbulence to sudden change of bed roughness in open-channel flow.” J. Hydraul. Eng., 129(1), 35–43.
Chiu, C. L., and Tung, N. C. (2002). “Maximum velocity and regularities in open-channel flow.” J. Hydraul. Eng., 128(4), 390–398.
Ervine, D. A., Babaeyan-Koopai, K., and Sellin, R. H. J. (2000). “Two-dimensional solution for straight and meandering overbank flows.” J. Hydraul. Eng., 126(9), 653–669.
Guo, J., and Julien, P. Y. (2005). “Shear stress in smooth rectangular open channel flows.” J. Hydraul. Eng., 131(1), 30–37.
Hayt, W. H. (1981). Engineering electromagnetics, 4th Ed., McGraw-Hill, New York.
Henderson, F. M. (1966). Open channel hydraulics, Macmillan, New York.
Hinze, J. O. (1975). Turbulence, McGraw-Hill, New York.
Knight, D. W., Shiono, K., and Pirt, J. (1989). “Prediction of depth mean velocity and discharge in natural rivers with overbank flow.” Proc., Int. Conf. on Hydraulics and Environmental Modeling of Coastline, Estuaries and River Waters, Univ. of Bradford, Sep. Gower, Aldershot, U.K., 419–428.
Lee, M. C., Lai, C. J., Leu, J. M., Plant, W. J., Keller, W. C., and Hayes, K. (2002). “Noncontact flood discharge measurements using an X-band pulse radar (I) theory.” Flow Meas. Instrum., 13, 265–270.
Maghrebi, M. F. (2003). “Discharge estimation in flumes using a new technique for the production of isovel contours.” Proc., Int. Conf. on Civil and Environmental. Engineering, ICCEE, Hiroshima, Japan, 147–156.
Smart, G. M., Duncan, M. J., and Walsh, J. M. (2002). “Relatively rough flow resistance equations.” J. Hydraul. Eng., 128(6), 568–578.
Wright, S., and Parker, G. (2004). “Density stratification effects in sandbed rivers.” J. Hydraul. Eng., 130(8), 783–795.
Yen, B. C. (2002). “Open channel flow resistance.” J. Hydraul. Eng., 128(1), 20–39.
Information & Authors
Information
Published In
Copyright
© 2006 ASCE.
History
Received: Nov 3, 2003
Accepted: Oct 12, 2005
Published online: Oct 1, 2006
Published in print: Oct 2006
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.