Vibration of Beams and Trashracks in Parallel and Inclined Flows
Publication: Journal of Hydraulic Engineering
Volume 117, Issue 8
Abstract
The dynamic load and cross‐flow response of trashrack bars and single beams subject to an incident flow was investigated for a wide range of cross‐sectional shapes, bar spacings, and flow incidence angles. At zero flow incidence, rectangular profiles with a depth‐to‐thickness ratio less than six were found to be susceptible to two mechanisms of vortex‐induced vibration: one due to Karman vortices, the other due to impinging leading‐edge vortices. Longer rectangular profiles at zero flow incidence were stable. Rounding the edges, especially those facing the flow, resulted in an increased intensity of excitation due to Karman vortices. At small flow‐incidence angles up to 15°, vortex excitation became weaker and turbulent buffeting set in. Reducing the bar spacing had a similar effect, attributable to the interference of adjacent bar wakes. Design recommendations are given to avoid serious flow‐induced vibrations.
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References
1.
Behring, A. G., and Yeh, C. H. (1979). “Flow‐induced trashrack vibration.” Proc. Fluids Engrg. and Bioengrg. Conf., American Society of Mechanical Engineers‐Canadian Society of Mechanical Engineers, 125–134.
2.
Bugl, H., and Jericha, H. (1968a). “Fragen der Dimensionierung und Ausbildung der Rechenanlagen vor den Turbineneinlaeufen von Flusskraftwerken.” Oest. Ing. Zeitschrift, 11(3), 81–84 (in German).
3.
Bugl, H., and Jericha, H. (1968b). “Fragen der Dimensionierung und Ausbildung der Rechenanlagen vor den Turbineneinlaeufen von Flusskraftwerken.” Oest. Ing. Zeitschrift, 11(4), 129–135 (in German).
4.
Blake, W. K. (1986). Mechanics of flow‐induced sound and vibration. Vol. 2, Academic Press, New York, N.Y., 761.
5.
Blevins, R. D. (1977). Flow‐induced vibration. 1st Ed., Van Nostrand Reinhold Company, New York, N.Y.
6.
Corless, R. M., and Parkinson, G. V. (1988). “A model of the combined effects of vortex‐induced oscillation and galloping.” J. Fluids Struct., 2, 203–225.
7.
Gruseck, T. (1988). “Experimental study on the streamwise and transverse response of rectangular bars,” thesis presented to the Institute of Hydromechanics, University of Karlsruhe, at Karlsruhe, Germany, in partial fulfillment of the requirements for the degree of Master of Science (in German).
8.
Kirschmer, O. (1926). Untersuchungen uber den Verlust an Rechen. Mitteilungen Hydraulisches Institut Muenchen, Muenchen, Germany (in German).
9.
Knisely, C. (1985). “Strouhal numbers of rectangular cylinders at incidence.” Report SFB 210/E/13, Sonderforschungsbereich 210, University of Karlsruhe, Karlsruhe, Germany.
10.
Komatsu, S., and Kobayashi, H. (1980). “Vortex‐induced oscillation of bluff cylinders.” J. Wind Engrg. Indust. Aerodyn., Amsterdam, The Netherlands, 6, Nov., 335–362.
11.
Laroche, M. (1988). “Model tests on the streamwise and transverse response of a trashrack,” thesis presented to the Institute of Hydromechanics, University of Karlsruhe, at Karlsruhe, Germany, in partial fulfillment of the requirements for the degree of Master of Science (in German).
12.
Levin, L. (1957). “Etudes hydrauliques des Grilles de Prise d'Eau.” Proc. 7th General Meeting, International Association for Hydraulic Research, Lisbon, Portugal, 1(C11), 1–11 (in French).
13.
Levin, L. (1967). “Probleme de Perte de Charge et de Stabilite' des Grilles de Prise d'Eau.” La Houille Blanche, Paris, France, 22(3), 271–278 (in French).
14.
Nakamura, Y. (1979). “On the aerodynamic mechanism of torsional flutter of bluff structures.” J. Sound Vib., 67(2), 471–499.
15.
Nakamura, Y., and Mizota, T. (1975). “Unsteady lifts and wakes of oscillating rectangular prisms.” J. Engrg. Mech., ASCE, 101(6), 854–871.
16.
Naudascher, E. (1987). “Flow‐induced streamwise vibration of structures.” J. Fluids Struct., 1, 265–298.
17.
Nguyen, T. D., Rao, B. C. S., and Naudascher, E. (1988). “Field and model studies on trashrack vibrations.” Proc. Int. Symp. on Model‐Prototype Correlation of Hydraulic Structures, ASCE, 334–343.
18.
Novak, M. (1971). “Galloping and vortex‐induced oscillations of structures.” Proc. Third Int. Conf. on Wind Effects on Bldgs. and Struct., Sailcon Co., Ltd., Tokyo, Japan, 799–809.
19.
Parker, R., and Welsh, M. C. (1983). “Effects of sound on flow separation from blunt flat plates.” Int. J. Heat Fluid Flow, 4(2), 113–127.
20.
Parkinson, G. V. (1974). “Mathematical models of flow‐induced vibrations of bluff bodies.” Proc. Symp. on Flow‐Induced Vibrations of Bluff Bodies, Int. Assoc. for Hydraulic Research and Int. Union of Theoretical and Applied Mechanics, 81–127.
21.
“Reversible flow trashracks.” (1983). Document 7735A. ASCE Task Committee on Design and Performance of Reversible Flow Trashracks, Committee on Hydr. Struct., ASCE, New York, N.Y.
22.
Rockwell, D. O., and Naudascher, E. (1979). “Self‐sustained oscillations of impinging free shear layers.” Ann. Rev. Fluid Mech., 11, 67–94.
23.
Schlageter, G. (1985). “Erfahrungen an Maschinenhausrechen des RADAG.” Wasser, Energie, Luft, Baden‐Switzerland, 77(10), 293–299 (in German).
24.
Sell, L. E. (1971). “Hydroelectric power plant trashrack design.” J. Power Div., ASCE, 97(1), 115–121.
25.
Shiraishi, N., and Matsumoto, M. (1983). “On classification of vortex‐induced oscillation and its application for bridge structures.” Proc. Int. Conf. on Wind Engineering, Technische Hochschule, Aachen, West Germany, 418–430.
26.
Vigander, S., and March, P. A. (1979). “Trashrack vibration studies, Raccoon Mountain Pumped Storage Project.” TVA Engineering Laboratory Report No. 43‐47; Tennessee Valley Authority, Norris, Tenn.
27.
Washizu, K., Ohya, A., Otsuki, Y., and Fujii, K. (1978). “Aeroelastic instability of rectangular cylinders in a heaving mode.” J. Sound Vib., 59(2), 195–210.
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Copyright © 1991 ASCE.
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Published online: Aug 1, 1991
Published in print: Aug 1991
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