Approach‐Flow Effects on Downpull of Gates
Publication: Journal of Hydraulic Engineering
Volume 109, Issue 11
Abstract
The effects of various approach‐flow conditions upon the down‐pull, the local pressures, and the discharge characteristics have been investigated for intake gates. Laser‐Doppler‐Anemometry measurements near the separation point of the gate bottom permit detailed specification of turbulence conditions. The partly strong variation of down‐pull and discharge coefficient for the different approach flows considered is traced to the sensitivity of the separated‐flow pattern near bluff bodies to freestream turbulence, and to changes in the mean‐flow incidence. For the particular gate studied, local flow separation from a protruding bottom girder and the placement of a trash‐rack‐like grid at a short distance upstream from the gate are shown to yield opposite effects on the downpull coefficient as compared to mere freestream turbulence. In analogy to the observations of flows around prisms, two separated‐flow regimes with and without reattachment are identified in the flow around the gate bottom, and the observed effects of turbulence on the downpull and discharge are interpreted in terms of changes in the separation patterns. The results can be generalized and applied to geometrical configurations other than those studied.
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References
1.
Bearman, P. W., “An Investigation of the Forces on Flat Plates Normal to a Turbulent Flow,” Journal of Fluid Mechanics, London, England, Vol. 46, 1971, pp. 177–198.
2.
Bearman, P. W., “Some Measurements of the Distortion of Turbulence Approaching a Two‐dimensional Bluff Body,” Journal of Fluid Mechanics, London, England, Vol. 53, 1972, pp. 451–467.
3.
Bergholz, J., “Bestimmung der Turbulenz‐ und Geschwindigkeitsverteilungen mittels Laser‐Doppler‐Anemometrie und deren Einfluss auf die Druckverteilung an einem unterströmten Schützmodell,” Vertieferarbeit No. 483, Institut für Hydromechanik, Universität Karlsruhe, Germany, 1981.
4.
Gartshore, I. S., “The Effects of Freestream Turbulence on the Drag of Rectangular Two‐dimensional Prisms,” Research Report BLWT‐4‐73, Boundary Layer Wind Tunnel Laboratory, Faculty of Engineering Science, Univ. of Western Ontario, Ontario, Canada, 1973.
5.
George, W. K., “Processing of Random Signals,” Proceedings of the Dynamic Flow Conference, Marseille, France, 1978, pp. 757–793.
6.
Hinze, J. O., Turbulence, McGraw‐Hill Book Co., New York, Toronto, London, 1959, pp. 39–42.
7.
Hunt, J. C. R., “A Theory of Turbulent Flow Round Two‐dimensional Bluff Bodies,” Journal of Fluid Mechanics, London, England, Vol. 61, 1973, pp. 625–706.
8.
Jenkins, G. M. and Watts, D. G., Spectral Analysis and its Applications, 2nd ed., Holden‐day, San Francisco, 1969, Chapter 6.
9.
Kwok, K. C. S., and Melbourne, W. H., “Freestream Turbulence Effects on Galloping,” Journal of the Engineering Mechanics Division, ASCE, Vol. 106, No. EM2, Proc. Paper 15356, Apr., 1980, pp. 273–288.
10.
Laneville, A. and Parkinson, G. V., “Effects of Turbulence on Galloping of Bluff Cylinders,” Proceedings, Third International Conference on Wind Effects on Buildings and Structures, Saikon Co., 1971, pp. 787–798.
11.
Laneville, A., Gartshore, I. G. and Parkinson, G. V., “An Explanation of some Effects of Turbulence on Bluff Bodies,” Proceedings, Fourth International Conference on Wind Effects on Buildings and Structures, Cambridge University Press, 1975.
12.
Laneville, A. and Williams, C. D., “The Effect of Intensity and Large Scale Turbulence on the Mean Pressure and Drag Coefficients of Two‐dimensional Rectangular Cylinders,” Fifth International Conference on Wind Engineering, Fort Collins, Colo., 1979.
13.
Meier, H. J., “Messungen der hydrodynamischen Belastung an unterströmten Schützen mit leicht geneigter Sohle,” Vertieferarbeit No. 474, Institut für Hydromechanik, Universität Karlsruhe, Germany, 1980.
14.
Melbourne, W. H., “Turbulence Effects on Maximum Surface Pressures—A Mechanism and Possibility of Reduction,” Fifth International Conference on Wind Engineering, Fort Collins, Colo., 1979.
15.
Mills, R. R., Jr. and Corrsin, S., “Effect of Contraction on Turbulence and Temperature Fluctuations Generated by a Warm Grid,” NASA‐Memorandum 5‐5‐59W, Washington, May, 1959.
16.
Naudascher, E., Kobus, H., and Rao, R. R. R., “Hydrodynamic Analysis for High‐Head Gates,” Journal of the Hydraulics Divisbn, ASCE, Vol. 90, No. HY3, Proc. Paper 3904, May, 1964, pp. 155–192.
17.
Naudascher, E., and Locher, F., “Flow‐Induced Forces on Protruding Walls,” Journal of the Hydraulics Division, ASCE, Vol. 100, No. HY2, Proc. Paper 10347, Feb., 1974, pp. 295–313.
18.
Rockwell, D. O., “Organized Fluctuations Due to Flow Past a Square Cross Section Cylinder,” Transactions, ASME, Journal of Fluids Engineering, Vol. 99, Sept., 1977, pp. 511–516.
19.
Schanz, H. W., “Experimentelle Untersuchung der hydrodynamischen Beanspruchung von Tiefschützen,” Diplomarbeit No. 434, Institut für Hydromechanik, Universität Karlsruhe, Germany, 1978.
20.
Tan‐atichat, J., Nagib, H. M. and Drubka, R. E., “Effects of Axisymmetric Contractions on Turbulence of Various Scales,” NASA Contractor Report 165136, Illinois Institute of Technology, Chicago, Ill., Sept., 1980, pp. 202–203.
21.
Van Atta, C. W., “Sampling Techniques in Turbulence Measurements,” Annual Review of Fluid Mechanics, Vol. 6, 1974, pp. 75–91.
22.
Vickery, B. J., “Fluctuating Lift and Drag on a Long Cylinder of Square Cross‐Section in a Smooth and in a Turbulent Stream,” Journal of Fluid Mechanics, London, England, Vol. 25, 1966, pp. 481–494.
23.
Wedding, J. B., Robertson, J. M., Peterka, J. A., and Akins, R. E., “Spectral and Probability‐Density Nature of Square‐Prism Separation‐Reattachment Wall Pressures,” Journal of Fluids Engineering, Vol. 100, Dec., 1978, pp. 485–492.
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Copyright © 1983 ASCE.
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Published online: Nov 1, 1983
Published in print: Nov 1983
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