On some aspects of fully-developed turbulent flow in rectangular channels

Gessner, F. B.; Jones, J. B.

doi:10.1017/s0022112065001635

Cited by 178 publications

(83 citation statements)

References 6 publications

(3 reference statements)

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“…The computations by Nakayama, et al (1983) are based on the algebraic stress model developed by Launder & Ying (1972). It can be seen here that the present model agrees with the experimental results of Gessner and Jones (1965) in the sense that it also exhibits weaker secondary flow velocities near the center of the duct. The computations were then extended to flow in curved ducts.…”

Section: Resultssupporting

confidence: 83%

“…Such secondary flows not only cause a reduction in the volumetric flow rate, but they can also cause the axial velocity field to be distorted with an outward shift of the contours of constant velocity. In addition, it is well known that the turbulent flow in straight noncircular ducts is characterized by the occurrence of secondary flows (see Jones 1965 andNakayama et al, 1983). A clear understanding of the evolution and consequences of the turbulent secondary flows in curved and straight ducts is, therefore, quite important from the design standpoint.…”

Section: Introductionmentioning

confidence: 99%

“…The case of fully-developed turbulent flow in straight ducts of square cross section was studied by Gessner and Jones (1965), Melling and Whitelaw (1976), and Nakayama, et al (1983), among others. Gessner and Jones (1965) conducted a series of experiments using hotwire anemometry to analyze fully-developed turbulent flow in a square duct at a Reynolds number of 150,000. They also carried out computations by a finite difference method with an algebraic stress model to predict qualitatively the major feature of the flowfield, namely, the eight-vortex secondary flow structure.…”

Section: Introductionmentioning

confidence: 99%

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Numerical Study of Turbulent Secondary Flows in Curved Ducts

Hur

Thangam

Speziale

1990

Journal of Fluids Engineering

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The pressure driven, fully-developed turbulent flow of an incompressible viscous fluid in curved ducts of square cross-section is studied numerically by making use of a finite volume method. A nonlinear K -I model is used to represent the turbulence. The results for both straight and curved ducts are presented. For the case of fully-developed turbulent flow in straight ducts, the secondary flow is characterized by an eight-vortex structure for which the computed flowfield is shown to be in good agreement with available experimental data. The introduction of moderate curvature is shown to cause a substantial increase in the strength of the secondary flow and to change the secondary flow pattern to either a double-vortex or a four-vortex configuration.

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Section: Resultssupporting

confidence: 83%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Numerical Study of Turbulent Secondary Flows in Curved Ducts

Hur

Thangam

Speziale

1990

Journal of Fluids Engineering

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“…In previous work, Gessner and Jones [1965] found that values of L/R of 160 (for a square duct) and 240 also gave fully developed conditions. Nezu and Rodi [1986] used L/R of 326 for their analyses in open channel flow.…”

Section: Measurement Locationsmentioning

confidence: 88%

The study of unsteady pipe flow and non-uniform channel flow by the use of laser doppler anemometry

Johnson¹

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Steady fluid flow within circular pipelines has been the subject of very extensive research for well over 100 years. However, unsteady flows, particularly those at transitional and higher Reynolds Numbers, have not been nearly so well analyzed.Consequently, although there is now an essentially complete description of the hydraulic and fluids mechanics aspects of steady flow, the understanding of turbulent unsteady flow phenomena is much less certain.The major difficulty in working in the unsteady flow area is the inherent nature of the flow. That is, the unsteadiness of the velocity vector requires a measurement device that does not rely upon time-averaging techniques to produce estimates of the velocity magnitude. For this reason alone, the laser-Doppler anemometer (LDA) is an ideal instrument for analysis of unsteady flows. In addition, it is non-intrusive and so does not affect the structure of the flow during the measurement process.Experimental procedures were developed successfully to enable the accurate measurement of mean velocity and turbulence intensity in monotonically varying unsteady pipe flow. Previous research at the University of Queensland had produced unexpected results in relation to this class of flow, and it was considered that a more detailed experimental analysis would yield important information.More specifically, the concept of quasi-steadiness of the flow was examined. In parallel with the experimental program, theoretical analyses were undertaken to derive methods for determining whether flow at a particular time instant is quasi-steady in nature. A modified simple power law was developed, which enables the flow rate and velocity profile in a steady turbulent flow to be estimated accurately from a single measurement of the centreline velocity. From the same velocity measurement, a law of the wall was used to derive estimates of the friction velocity and hence turbulence intensities over the entire cross-section. niIt was found that velocity profiles in monotonically unsteady turbulent flow were indistinguishable from the corresponding profiles for steady flow at the equivalent Reynolds Number. However, turbulence intensities, in flow under the effect of an acceleration transient, were shown to be significantly smaller than quasi-steady. This is consistent with a lagging process. Under these conditions, it was also found that the onset of laminar-turbulent transition was very significantly delayed (to Re in excess of 100 X 10^). The behaviour around the time of transition was examined in detail, with the conclusion that transition to fully developed turbulent flow occurred much more rapidly in accelerating flow than under steady flow conditions. The LDA was also used to study the behaviour within an open channel flow transition, where the flow area remains constant throughout the transition, but the aspect ratio varies continuously. The channel chosen was such that the width of flow converged as the bed level fell away. Previous research has shown that this form of channel exhib...

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“…Measurements to determine the orientation of the traces of turbulent-stress principal planes in ducts of non-circular cross-section were carried out by Gessner and Jones [5] and by Perkins [10]. The latter believed it reasonable to hypothesize that the direction with respect to which the turbulent shear-stress value in the cross-section appears to be maximum will always remain aligned to the isovels, even in the presence of secondary currents or of distortions in the flow field due to the shape of the contour.…”

Section: Introduction Les éCoulements Turbulentsmentioning

confidence: 99%

Turbulent shear-stresses and velocity distribution in open-channel flows

Gaddini¹,

Morganti²

1982

La Houille Blanche

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IntroductionOpen-channel turbulent flows often present considerably complex aspects so that ordinary hydraulic formulas such as the pipe resistance law and logarithmic velocity distribution along the normals to the walls are unfortunately not directly applicable.It was learned that to determine the velocity field and the friction factor in open-channels with sufficient accuracy, it is necessary to evaluate the effects both of the shape of the cross-section and of the non-uniform distribution of the shear-stresses over the wetted perimeter . These factors in fact determine a threedimensional flow in open channels. The flow can be considered to be defmed by the superimposition of a primary flow and a secondary flow. The primary flow actually moves the fluid in the longitudinal direction of the channel. The secondary flow can be separated, according to the classification formulated by Prandtl [11], into a secondary flow of the fust kind (a result of variations in the cross-section) and a secondary flow of the second kind (showing closed streamlines that can be grouped in several cells). The latter motion is due to a non-homogeneous distribution of the turbulent velocity fluctuations in the boundarylayer.

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On some aspects of fully-developed turbulent flow in rectangular channels

Cited by 178 publications

References 6 publications

Numerical Study of Turbulent Secondary Flows in Curved Ducts

Numerical Study of Turbulent Secondary Flows in Curved Ducts

The study of unsteady pipe flow and non-uniform channel flow by the use of laser doppler anemometry

Turbulent shear-stresses and velocity distribution in open-channel flows

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