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Pulsating flow in a pipe

Published online by Cambridge University Press:  20 April 2006

L. Shemer
Affiliation:
Department of Fluid Mechanics and Heat Transfer, Faculty of Engineering, Tel-Aviv University, Ramat-Aviv 69978, Israel
I. Wygnanski
Affiliation:
Department of Fluid Mechanics and Heat Transfer, Faculty of Engineering, Tel-Aviv University, Ramat-Aviv 69978, Israel
E. Kit
Affiliation:
Department of Fluid Mechanics and Heat Transfer, Faculty of Engineering, Tel-Aviv University, Ramat-Aviv 69978, Israel

Abstract

Turbulent and laminar pulsating flows in a straight smooth pipe are compared at identical frequencies and Reynolds numbers. Most measurements were made at a mean Reynolds number of 4000, but the influence of Re was checked for 2900 < Re < 7500. The period of forcing ranged from 0.5 to 5 s, with corresponding change in the non-dimensional frequency parameter α = R √(ω/ν) from 4.5 to 15. The amplitude of the imposed oscillations did not exceed 35% of the mean in order to avoid flow reversal or relaminarization. Velocities at the exit plane of the pipe and pressure drop along the pipe were measured simultaneously; velocity measurements were made with arrays of normal hot wires. The introduction of the periodic surging had no significant effect on the time-averaged quantities, regardless of the flow regime (i.e. in both laminar and turbulent flows). The time-dependent components at the forcing frequency, represented by a radial distribution of amplitudes and phases, are qualitatively different in laminar and turbulent flows. The ensemble-averaged turbulent quantities may also be represented by an amplitude and a phase; however, the non-harmonic content of these intensities increases with increasing amplitude of the imposed oscillations. A normalization procedure is proposed which relates phase-locked turbulent flow parameters in unsteady flow to similar time-averaged quantities. An integral momentum equation in a time-dependent flow requires that a triad of forces (pressure, inertia and shear) will be in equilibrium at any instant of time. All the terms in the force-balance equation were measured independently, providing a good check of data. The analysis of the experimental results suggests that turbulence adjusts rather slowly to the local mean-flow conditions. A simple eddy-viscosity model described by a complex function can account for ‘memory’ of turbulence and explain the different phase distribution in laminar and turbulent flows.

Type
Research Article
Copyright
© 1985 Cambridge University Press

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References

Brown, F. T., Margolis, D. L. & Shah, R. P. 1969 Small-amplitude frequency behavior of fluid lines with turbulent flow. Trans. ASME D: J. Basic Engng 91. 678–693.Google Scholar
Caro, C. G., Pedley, T. Y., Schrotter, R. C. & Seed, W. A. 1978 The Mechanics of the Circulation. Oxford University Press.
Denison, F. B. 1970 Ph.D. Thesis, Purdue University, Lafayette, Ind.
Denison, E. B., Stevenson, W. H. & Fox, R. W. 1971 Pulsating laminar flow measurements with a directionally sensitive laser velocimeter. AIChE J. 17, 781787.Google Scholar
Hussain, A. K. M. F. 1977 Mechanics of pulsatile flows in relevance to the cardiovascular systems. In Cardiovascular Flow Dynamics and Measurements (ed. N. H. C. Hwang & N. A. Normann). Baltimore: University Park Press.
Hussain, A. K. M. F. & Reynolds, W. C. 1970 The Mechanics of an organized wave in turbulent shear flow. J. Fluid Mech. 41, 241258.Google Scholar
Kirmse, R. E. 1979 Investigations of pulsating turbulent pipe flow. Trans ASME I: J. Fluids Engng 101, 436442Google Scholar
Laufer, J. 1954 NACA Rep. No. 1174.
Laufer, J. & Badri Narayanan, M. A. 1971 Mean period of the turbulent production mechanism in a boundary layer, Phys. Fluids 14, 241258.Google Scholar
Oster, D. 1980 Ph.D. Thesis, Tel-Aviv University, Tel-Aviv.
Oster, D. & Wygnanski, I. 1982 The forced mixing layer between parallel streams. J. Fluid Mech. 123, 91130.Google Scholar
Narasimha, R. & Prabhu, A. 1972 Equilibrium and relaxation in turbulent wakes. J. Fluid Mech. 54, 117.Google Scholar
Nee, V. W. & Kovasznay, L. S. G. 1969 Simple phenomenological theory of turbulent shear flows. Phys. Fluids 12, 473484.Google Scholar
Ramaprian, B. R. & Tu, S.-W. 1980 An experimental study of oscillatory pipe flow at transitional Reynolds numbers. J. Fluid Mech. 100, 513544.Google Scholar
Schlichting, H. 1975 Boundary Layer Theory. McGraw-Hill.
Sexl, T. 1930 Ueber den von E. G. Richardson entdeckten ‘Annulareffekt‘, Z. Phys. 61, 349362.Google Scholar
Shemer, L. 1981 Ph.D. Thesis, Tel-Aviv University, Tel-Aviv.
Shemer, L. & Kit, E. 1984 An experimental investigation of the quasi-steady turbulent pulsating flow in a pipe. Phys. Fluids 27, 7276.Google Scholar
Shemer, L. & Wygnanski, I. 1981 Pulsating flow in a pipe. In Proc. 3rd Symp. on the Turbulent Shear Flows, Davis, Cal., 8.13–8.18.
Tu, S.-W. & Ramaprian, B. R. 1983 Fully developed periodic turbulent pipe flow in a tube. J. Fluid Mech. 137, 3158.Google Scholar
Uchida, S. 1956 Pulsating viscous flow superposed on the steady laminar motion. Z. angew. Math. Phys. 7, 403422.Google Scholar
Womersley, J. R. 1955 Method for the calculation of velocity rate of flow and viscous drag in arteries when the pressure gradient is known. J. Physiol. 127, 553572.Google Scholar
Wygnanski, I. J. & Champagne, F. H. 1973 On transition in a pipe. Part I. The origin of puffs and slugs and the flow in a turbulent slug. J. Fluid Mech. 59, 281335.Google Scholar