This paper describes a new and efficient model for the study of air entrainment effects on the responses of a typical horizontal air vessel. The effects of air entrainment on the pressure surges for unsteady flow in a pipeline system were investigated. Studies showed that entrained, entrapped, or released gases in the transient fluid system tend to amplify the first pressure peak, increase surge damping, and produce asymmetric pressure surges with respect to the static head. The pressure surges showed longer periods of down-surge and shorter periods of upsurge. The upsurge was considerably amplified and down-surge was marginally reduced when compared with the gas-free case. With the horizontal air vessel installed, studies showed that the effects of air entrainment on the maximum transient pressure can be considerably reduced with an appropriately configured air vessel. [S0098-2202(00)00203-0]
Issue Section:
Technical Papers
1.
Clarke, D. S., 1985, “Surge Suppression—A Warning,” Proceedings of the International Conference on the Hydraulics of Pumping Stations, Manchester, England, 17-19 Sept., pp. 39–54.
2.
Graze, H. R., and Horlacher, H. B., 1986, “Design Charts for Throttle (By-Pass) Air Chamber,” 5th Int. Conference on Pressure Surges, Hannover, Germany, 22–24 Sept., pp. 309–322.
3.
Martin, C. S., 1972, “Method of Characteristics Applied to Calculation of Surge Tank Oscillations,” Proceedings of the International Conference on Pressure Surges, University of Kent, Canterbury, England, 6–8 Sept., pp. E1-1 to E1-12.
4.
Fok
, A. T. K.
, 1978
, “Design Charts for Air Chamber on Pump Pipe Lines
,” J. Hydraul. Div., Am. Soc. Civ. Eng.
, HY9
, Sept., pp. 1289
–1302
.5.
Evans
, W. E.
, and Crawford
, C. C.
, 1954
, “Design Charts for Air Chambers and Pump Lines
,” Trans. Am. Soc. Civ. Eng.
, 119
, pp. 1025
–1045
.6.
Fox, J. A., 1984, Hydraulic Analysis of Unsteady Flow In Pipe Network, Macmillan Press, London.
7.
Wylie, E. B., Streeter, V. L., and Suo, L., 1993, Fluid Transients in Systems, McGraw-Hill, New York.
8.
Lee, T. S., and Cheong, H. F., 1998, “Tanjong Rhu Pumping Station—Site Measurement and Analysis of Surge in Pumping Main,” Ebara Engineering Singapore Pte Ltd., Singapore, July.
9.
Thorley, A. R. D., and Lastowiecki, P., 1985, “Air Vessel Design for Rising Mains,” Proceedings of the International Conference on the Hydraulics of Pumping Stations, Manchester, England, 17–19 Sept., pp. 89–98.
10.
Allievi
, L.
, 1937
, “Air Chamber for Discharge Lines
,” Trans. ASME
, 59
, pp. 651
–659
.11.
Angus
, R. W.
, 1937
, “Air Chambers and Air Valves in Relation to Water Hammer
,” Trans. ASME
, 59
, pp. 661
–668
.12.
Lee
, T. S.
, and Pejovic
, S.
, 1996
, “Air influence on similarity of hydraulic transients and vibrations
,” ASME J. Fluids Eng.
, 118
, pp. 706
–709
.13.
Pearsall
, I. S.
, 1965/66
, “The Velocity of Water Hammer Waves
,” Symposium on Surges in Pipelines, Proc. Inst. Mech. Eng.
, Vol. 180
, Part 3E, pp. 12
–20
.14.
Kranenburg
, C.
, 1974
, “Gas release during transient cavitation in pipes
,” J. Hydraul. Div., Am. Soc. Civ. Eng.
, 100
, pp. 1383
–1398
.15.
Provoost, G. A., 1976, “Investigation into Cavitation in a Prototype Pipeline caused by Waterhammer,” Proc. Second Int. Conf. on Pressure Surges, Bedford, England, BHRA, Sept., pp. 35–43.
16.
Chaudhry
, M. H.
, Bhallamudi
, S. M.
, Martin
, C. S.
, and Naghash
, M.
, 1990
, “Analysis of Transient Pressures in Bubbly, Homogeneous, Gas-Liquid Mixtures
,” ASME J. Fluids Eng.
, 112
, pp. 225
–231
.17.
Jonsson, L., 1985, “Maximum Transient Pressures in a Conduit with CheckValve and Air Entrainment,” International Conference on the Hydraulics of Pumping Stations, The University of Manchester Institute of Science and Technology (UMIST) & BHRA—The Fluid Engineering Centre, England. 17–19 Sept., pp. 55–76.
18.
Whiteman
, K. J.
, and Pearsall
, I. S.
, 1959
, “Reflux Valve and Surge Tests at Kingston Pumping Station
,” Brit. Hydromech. Res. Assoc./National Engineering Laboratory Joint Report No. 1, Apr.1.
Whiteman
, K. J.
, and Pearsall
, I. S.
, 1962
, “Reflux Valve and Surge Tests at a Station
,” Fluid Handling
, XIII
, Sept. and Oct., pp. 248
–250
2.
XIII
and 282
–286
1.
Dawson
,, P. A.
, and Fox
, J. A.
, 1983
, “Surge Analysis and Suppression Techniques for a Water Supply Scheme—A Case Study
,” Trans. Inst. M. C.
, 5
, No.4
, pp. 134
–142
.2.
Falconer, R. H., Banks, W., and Ellis, J., 1983, “Surge Pressures at Riding Mill Pumping Station: Actual Values and Theoretical Predictions,” 4th International Conference on Pressure Surges, University of Bath, England. Sept. 21–23, pp. 427–445.
Copyright © 2000
by ASME
You do not currently have access to this content.
