Journal ArticleDOI
An experimental investigation of pulsating turbulent water flow in a tube
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In this paper, experiments were made on a pulsating water flow at a mean flow Reynolds number of 3770 in a cylindrical tube of diameter 3·81 cm, where a piston oscillated in simple harmonic motion with a period of 12 s.Abstract:
Experiments were made on a pulsating water flow at a mean flow Reynolds number of 3770 in a cylindrical tube of diameter 3·81 cm. Pulsations were produced by a piston oscillating in simple harmonic motion with a period of 12 s. Turbulence was made visible by means of a sheet of dye produced by electrolysis from a fine wire stretched across a diameter. The sheet of dye is contorted by the turbulent eddies, and cine-photography was used to find the velocity of convection which was shown to be the flow speed except in certain circumstances which are discussed. By subtracting the mean flow velocity profile the profile of the component of the motion oscillating at the imposed frequency was determined.The Reynolds number of these experiments lies in the turbulent transition range, so that large effects of laminarization are observed. In the turbulent phase, the velocity profile was found to possess a central plateau as does the laminar oscillating profile. The level and radial extent of this were little different from the laminar ones. Near to the wall, the turbulent oscillating profile is well represented by the mean velocity power law relationship, u/U ∝ (y/a)1/n. In the laminarized phase, the turbulent intensity is considerably reduced at this Reynolds number. The velocity profile for the whole flow (mean plus oscillating) relaxes towards the laminar profile. Laminarization contributes appreciably to the oscillating component.Extrapolation of the results to higher Reynolds numbers and different frequencies of oscillation is suggested.read more
Citations
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Journal ArticleDOI
Flow characteristics in models of arterial stenoses. II. Unsteady flow.
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TL;DR: It is shown that three dimensionless parameters can be used to characterize the unsteady flow in a stenosis and the effect of unsteadiness is investigated experimentally using axisymmetric and nonsymmetric models.
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A critical review on pulsatile pipe flow studies directing towards future research topics
TL;DR: In this article, the authors present the state of the art in pulsatile flow analysis based on a critical and commentary analysis of an extended review, covering the time period 1928-2000 to specify what is known together with the existing discrepancies, and what is unknown.
Journal ArticleDOI
Numerical analysis of heat transfer in pulsating turbulent flow in a pipe
Xuefeng Wang,Nengli Zhang +1 more
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ReportDOI
Studies of the wall shear stress in a turbulent pulsating pipe flow
TL;DR: In this paper, measurements of the time variation of the wall shear stress caused by the imposition of a sinusoidal oscillation on a turbulent pipe flow are presented, where the amplitude of the oscillation is small enough that a linear response is obtained and the dimensionless frequency, omega +, is large compared to that studied by most previous investigators.
References
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The Structure of Turbulence in Fully Developed Pipe Flow
TL;DR: In this paper, a hot-wire anemometer was used to measure the turbulent flow in a 10-inch pipe at speeds of approximately 10 and 100 feet per second, and the results include relevant mean and statistical quantities, such as Reynolds stresses, triple correlations, turbulent dissipation, and energy spectra.
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XXIV. Oscillatory motion of a viscous liquid in a thin-walled elastic tube—I: The linear approximation for long waves
TL;DR: In this article, the linear approximation for long waves was proposed. But the linear approximation was only applied to a viscous liquid in a thin-walled elastic tube, and it was not applied to the case of long waves.
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The pulsating viscous flow superposed on the steady laminar motion of incompressible fluid in a circular pipe
TL;DR: In this article, an exact solution of pulsating laminar flow superposed on the steady motion in a circular pipe is presented under the assumption of parallel flow to the axis of pipe.
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Some observations on skin friction and velocity profiles in fully developed pipe and channel flows
V. C. Patel,M. R. Head +1 more
TL;DR: In this paper, skin friction and mean-velocity profiles have been made in fully developed flows in pipes and channels in the Reynolds number range 1000 < Re < 10000, and observations of hot-wire signals indicate rather remarkable differences between two-dimensional and axially symmetric flows and also make it difficult to give a precise definition of the term "fully developed turbulent flow".
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Über den von E. G. Richardson entdeckten „Annulareffekt``
TL;DR: In this article, Richardson et al. present empirically empirische Gesetzmasigkeiten qualitativ and quantitatio-tiv aus den Stokes-Navierschen Grundgleichungen der Hydrodynamik, als fur eine oszillierende Laminarstromung in einem Kreisrohr charakteristisch, hergeleitet werden konnen.