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Journal ArticleDOI

Vorticity with different shapes of submerged vanes

01 Jan 2006-ISH Journal of Hydraulic Engineering (Taylor & Francis Group)-Vol. 12, Iss: 1, pp 13-26
TL;DR: In this paper, a dimensional analysis approach has been attempted to get dimensionless moment of momentum for the secondary circulation of a rectangular submerged vane with a collar and a double curve vane.
Abstract: At optimal angle of attack, vanes have the maximum strength of secondary circulation. For the same hydraulic condition, the maximum strength of vane induced secondary circulation also depends on their shapes. Optimal angle of attack in case of rectangular submerged vane with collar is very close to 40° where as in case of double curve vane type I, double curve vane type II, J1 type and J2 type vane is very close to 45°. Strength of vane induced secondary circulation in terms of moment of momentum depends upon various parameters. A dimensional analysis approach has been attempted to get dimensionless moment of momentum. The maximum strength of vane induced secondary circulation in terms of dimensionless moment of momentum is greater in case of rectangular vane than that in case of curved vanes in the same flow conditions and same height and length of vanes.
Citations
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Journal ArticleDOI
TL;DR: In this paper, the effect of the introduction of vanes in form of rows on parameters like turbulence intensities, Reynolds stresses, turbulent kinetic energy, anisotropy index, and the velocity profile of the flow was studied.

9 citations

Proceedings ArticleDOI
08 Aug 2017
TL;DR: In this paper, a rigid bed trapezoidal channel (side slopes, 1H: 1V) of bed width 15 cm, diverting at an angle of 45° from river model is used as an intake channel.
Abstract: River flow which is entering into an intake canal carries lot of sediment due to centrifugal action at river-intake junction and results in various problems. The present work aims to control sediment entry into an intake canal by modifying flow pattern using submerged vanes. Experiments are conducted in a 57.5 cm wide rectangular laboratory model filled with sediment, d50=0.28mm, for a constant discharge of 0.025m3/s and flow depth (H) of 8cm. A rigid bed trapezoidal channel (side slopes, 1H: 1V) of bed width 15 cm, diverting at an angle of 45° from river model is used as an intake channel. Submerged vanes of width 0.18H and 1mm thick are arranged in single and double rows at a spacing (Vs) of 8cm and 12cm. The angle of attack (θ) of vane with respect to flow direction in river model varies as 15°, 300 and 450. A total of seven vanes are arranged as a crest of wave with a central vane height of 0.625 H and decreasing gradually to 0.438H on either side. In single row vane arrangement, for ‘Vs’=8 cm and ‘θ’...

5 citations

Journal ArticleDOI
TL;DR: In this article, the design of river-based submerged vane matrices in a regional Australian context is studied, where the specific study site is proximal to intake screens within the riverbed that experiences
Abstract: This paper focuses on the design of river-based submerged vane matrices in a regional Australian context The specific study site is proximal to intake screens within the riverbed that experiences

4 citations

Journal ArticleDOI
23 Jun 2020
TL;DR: Submerged vanes are the hydrofoils which generate the helical currents in the flow due to the difference in pressure between the approaching flow side and the downstream side of vanes as discussed by the authors.
Abstract: Submerged vanes are the hydrofoils which generate the helical currents in the flow due to the difference in pressure between the approaching flow side and the downstream side of vanes and are place

4 citations

Journal ArticleDOI
TL;DR: In this paper, a series of experiments were performed with rectangular submerged vanes with and without a collar at Froude numbers 0.13 and 0.25, and the decay of vane strength does not follow a similar trend and appears sensitive to the location of center of vortex, Fournet number, etc.
Abstract: For spacing of vane arrays, the information about strength of vortex downstream of a submerged vane is needed. A series of experiments were performed with rectangular submerged vane with and without a collar at Froude numbers 0.13 and 0.25. To define the strength of vortex, a new set of dimensionless parameters using moment of momentum are involved. The present study provides certain information on the decay of strength of vortex with downstream of vane. The decay of vane strength does not follow similar trend and appears sensitive to the location of center of vortex, Froude number, etc. The streamwise spacing of submerged vanes may be taken at least 40H at optimal angle of attack. Centre of vortex is also observed to change with the downstream of submerged vane.

3 citations

References
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Book
01 Jan 1979
TL;DR: In this article, the non-tidal alluvial river is considered and the principles of river engineering are discussed, including the nontidal river engineering principles, and the importance of water flow in river engineering.
Abstract: Principles of river engineering: the non-tidal alluvial river , Principles of river engineering: the non-tidal alluvial river , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

207 citations

Journal ArticleDOI
TL;DR: Submerged vanes as mentioned in this paper are small flow-training structures (foils), designed to modify the near-bed flow pattern and redistribute flow and sediment transport within the channel cross section.
Abstract: Recent research results with the submerged‐vane technique for sediment control in rivers are described. Submerged vanes are small flow‐training structures (foils), designed to modify the near‐bed flow pattern and redistribute flow and sediment transport within the channel cross section. The structures are installed at an angle of attack of 15–25° with the flow, and their initial height is 0.2–0.4 times local water depth at design stage. The vanes function by generating secondary circulation in the flow. The circulation alters magnitude and direction of the bed shear stresses and causes a change in the distributions of velocity, depth, and sediment transport in the area affected by the vanes. As a result, the river bed aggrades in one portion of the channel cross section and degrades in another. The vanes can be laid out to develop and maintain any desired bed topography. Vanes have been used successfully for protection of stream banks against erosion and for amelioration of shoaling problems at water inta...

139 citations

Journal ArticleDOI
TL;DR: In this article, it was shown that short, vertical, submerged vanes installed at incidence to the channel axis in the outer half of a river-bend channel significantly reduce the secondary currents and the attendant undermining and high-velocity attack of the outer bank.
Abstract: It is shown, theoretically and by a physical model, that short, vertical, submerged vanes installed at incidence to the channel axis in the outer half of a river-bend channel significantly reduce the secondary currents and the attendant undermining and high-velocity attack of the outer bank. The effect of the vanes on the secondary flow is estimated by a simple torque calculation using the Kutta-Joukowski theorem. A design relation for the vane spacing is derived by equating the torque, about the channel centroid, produced by the flow curvature to that resulting from the lateral force exerted on the vanes. The relation is verified in an idealized, physical model of a bend of the Sacramento River, California.

133 citations

Journal ArticleDOI
TL;DR: In this paper, the authors describe the design, installation and performance of a system of submerged vanes for erosion protection in a bend of the East Nishnabotna River, Iowa.
Abstract: A summary is given of the design, installation and performance of a system of submerged vanes (“Iowa Vanes”) for erosion protection in a bend of East Nishnabotna River, Iowa. The system functions by eliminating, or reducing, the centrifugally induced helical motion of the flow (the root cause of bank undermining). The system was installed during the summer of 1985. Its performance was evaluated with data obtained in surveys in the spring of 1986. The system was found to effectively reduce velocity and scour along the bank without changing the energy slope of the channel. Areas of design improvements were identified. The summary includes a brief description of the theoretical and experimental background for the design.

109 citations

Journal ArticleDOI
TL;DR: In this paper, the effectiveness of vanes for preventing scour at single-span bridges with vertical wall abutments was evaluated based on laboratory experiments and the results showed that the vanes were highly effective in moving the scour away from the abutment into the center of the channel under all flow conditions tested.
Abstract: Rock vanes are single-arm structures angled to the flow with a pitch into the streambed such that the tip of the vane is submerged even during low flow. Vanes have primarily been used in recent years for treatment of bank erosion in stream stability projects. These structures roll the water away from the eroding banks, thus limiting erosion of the channel banks. They have proven to be very effective treatments over a range of flow conditions. In this project, the effectiveness of vanes for preventing scour at single-span bridges with vertical wall abutments was evaluated based on laboratory experiments. The vanes were tested in small-scale experiments in a recirculating flume and subjected to a range of flow conditions, including bank full and a number of overbank flows, which were forced to return to the channel at the abutment. The results showed that the vanes were highly effective in moving the scour away from the abutment into the center of the channel under all flow conditions tested. Based on the experimental results, optimum design settings for the vane angle and height, most effective number of vanes, and distance upstream for placement of the first vane were determined.

108 citations