Effects of Two-Dimensionality on Pipe Transients Modeling
Publication: Journal of Hydraulic Engineering
Volume 121, Issue 12
Abstract
The paper discusses the rapid damping of pressure peaks in a water-hammer phenomenon after the end of a complete valve-closure maneuver. This effect is due to flow characteristics not considered when one-dimensional models are employed. Such an effect is linked to the cross-sectional velocity profiles, and therefore to the intrinsic two-dimensionality of the flow field. Applying a 2-D model, recently proposed in the literature, to expand the limited experimental data available with numerical results, useful information on the evolution of the velocity profiles during a transient has been obtained. Starting from an in-depth inspection of the terms in the momentum equation, an additional term is introduced to model the effects of the flow-field two-dimensionality in a 1-D formulation. Finally, the adequacy of a relationship previously proposed by the writers to evaluate the additional term is specifically showed for fast transients in the field of low-Reynolds-number flows when no cavitation occurs, even if its validity has been proven elsewhere for rather different conditions.
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References
1.
Allievi, L. (1913). Teoria del Colpo d' Ariete . Atti del Collegio degli Ingegneri ed Architetti Italiani, Milan, Italy (in Italian).
2.
Barbero, B., and Ciaponi, C. (1990). “Experimental validation of a discrete free gas model for numerical simulation of hydraulic transients with cavitation.”Proc., Int. Conf. on Hydr. Transients with Water Column Separation, IAHR, Valencia, Spain, 51–67.
3.
Bergant, A., and Simpson, A. R. (1994). “Estimating unsteady friction in transient cavitating pipe flow.”Proc., 2nd Int. Conf. on Water Pipeline Systems, bHr Group, Edinburgh, Scotland, 3–16.
4.
Bratland, O. (1986). “Frequency-dependent friction and radial kinetic energy variation in transient pipe flow.”Proc., 5th Int. Conf. on Pressure Surges, BHRA, Hanover, Germany, D2, 95–101.
5.
Brunone, B., and Carravetta, A. (1994). “Daily management of irrigation pipe networks. Water hammer pressure surges and happened damages.”Proc., 2nd Int. Conf. on Water Pipeline Systems, bHr Group, Edinburgh, Scotland, 451–458.
6.
Brunone, B., De Marinis, G., and Golia, U. M. (1993). “On the flow rate curve determination through unsteady flow tests.” Symp. on La misura nella gestione delle infrastrutture idrauliche, Caserta-Napoli, Italy, 47–59 (in Italian).
7.
Brunone, B., and Golia, U. M. (1991). “Some considerations on velocity profiles in unsteady pipe flows.”Proc., Int Conf. on Entropy and Energy Dissipation in Water Resour., V. P. Singh and M. Fiorentino, eds., Maratea, Italy, 481–487.
8.
Brunone, B., Golia, U. M., and Greco, M. (1991a). “Modelling of fast transients by numerical methods.”Proc., Int. Conf. on Hydr. Transients with Water Column Separation, IAHR, Valencia, Spain, 273–280.
9.
Brunone, B., Golia, U. M., and Greco, M. (1991b). “Some remarks on the momentum equation for fast transients.”Proc., Int. Conf. on Hydr. Transients with Water Column Separation, IAHR, Valencia, Spain, 201–209.
10.
Brunone, B., and Greco, M. (1990). “Improvements in modelling of water hammer and cavitating flow in pipes. Experimental verification.”Proc., 22nd Convegno Nazionale di Idraulica e Costruzioni Idrauliche, Cosenza, Italy, 4, 147–160 (in Italian).
11.
Carravetta, A., Golia, U. M., and Greco, M. (1992). “On the spontaneous damping of pressure oscillations in water hammer transients.”Proc., 23rd Convegno Nazionale di Idraulica e Costruzioni Idrauliche, Florence, Italy, 4, E.67–79 (in Italian).
12.
Eichinger, P., and Lein, G. (1992). “The influence of friction on unsteady pipe flow.”Proc., Int. Conf. on Unsteady Flow and Fluid Transients, R. Bettess and J. Watts, eds., Balkema, Durham, England, 41–50.
13.
Golia, U. M. (1990). “On the evaluation of the friction term in water hammer phenomena.”Report n. 639, Dept. of Hydr. and Envir. Engrg., Univ. of Naples, Naples, Italy, 1–16 (in Italian).
14.
Greco, M.(1990). “Some recent findings on column separation during water hammer.”Excerpta, G.N.I., Libreria Progetto Ed., Padua, Italy, 5, 261–272.
15.
Hino, M., Masaki, S., and Shuji, T.(1976). “Experiments on transition to turbulence in an oscillatory pipe flow.”J. Fluid Mech., 75(2), 193–207.
16.
Holmboe, E. L., and Rouleau, W. T.(1967). “The effect of viscous shear on transients in liquid lines.”J. Basic Engrg., 89(1), 174–180.
17.
Jelev, I.(1983). “Computer analysis of hydraulic transients in pipe networks. Considerations concerning the head losses in the water hammer phenomena.”Proc., 20th IAHR Congress, Moscow, Russia, 6, 188–197.
18.
Jelev, I.(1989). “The damping of flow and pressure oscillations in water hammer analysis.”J. Hydr. Res., 27(1), 91–113.
19.
Jönsson, L. (1991). “Mean velocity profiles in transient flows.”Proc., Int. Conf. on Hydr. Transients with Water Column Separation, IAHR, Valencia, Spain, 99–113.
20.
Modica, C., and Pezzinga, G. (1992). “A quasi two-dimensional model of water hammer in turbulent flows.”Proc., 23rd Convegno Nazionale di Idraulica e Construzioni Idrauliche, Florence, Italy, 4, E.191–206 (in Italian).
21.
Montuori, C. (1989). Hydraulics . E.DI.S.U., Naples, Italy (in Italian).
22.
Nebbia, G. (1956). Hydraulics . Treves Ed., Naples, Italy (in Italian).
23.
Puppini, U. (1938). “Some remarks on the momentum equation for liquid flows.”L'Energia Elettrica, 15(10), 673–675 (in Italian).
24.
Shuy, E. B., and Apelt, C. J. (1983). “Friction effects in unsteady flows.”Proc., 4th Int. Conf. on Pressure Surges, BHRA, Bath, England, D2, 147–164.
25.
Simpson, A. R. (1986). “Large water hammer pressures due to column separation in sloping pipes,” PhD thesis, Dept. of Civ. Engrg., Univ. of Michigan, Ann Arbor, Mich.
26.
Suzuki, K., Taketami, T., and Sato, S.(1990). “Improving Zielke's method of simulating frequency-dependent friction in laminar liquid pipe flow.”J. Fluids Engrg., ASME, 113(4), 569–573.
27.
Trikha, A. K.(1975). “An efficient method for simulating frequency-dependent friction in transient liquid flow.”J. Fluids Engrg., 97, 97–105.
28.
Vardy, A. E. (1992). “Approximating unsteady friction at high Reynolds numbers.”Proc., Int. Conf. on Unsteady Flow and Fluid Transients, R. Bettess and J. Watts, eds., Balkema, Durham, England, 21–29.
29.
Vardy, A. E., and Hwang, K. L.(1991). “A characteristics model of transient friction in pipes.”J. Hydr. Res., 29(5), 669–684.
30.
Vardy, A. E., Hwang, K. L., and Brown, J. M. B.(1993). “A weighting function model of transient turbulent pipe friction.”J. Hydr. Res., 31(4), 533–548.
31.
Wiggert, D. C., and Sundquist, M. J.(1979). “The effect of gaseous cavitation on fluid transients.”J. Fluids Engrg., 101(1), 79–86.
32.
Zielke, W.(1968). “Frequency-dependent friction in transient pipe flow.”J. Basic Engrg., 90(1), 109–115.
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Copyright © 1995 American Society of Civil Engineers.
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Published online: Dec 1, 1995
Published in print: Dec 1995
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