Discussion of “Prediction of Intake Vortex Risk by Nearest Neighbors Modeling” by Quentin B. Travis and Larry W. Mays

Engineering Applications of Computational Fluid Mechanics

Zarrati

Jabbari

et al. 2014

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ABSTRACT:In the present work, a numerical study was performed to analyze the flow behavior in a reservoir in the presence of strong vortices. A challenging subject in this study was the flow field in the reservoir and the mechanism of vortex formation. The numerical model was verified with the available theories and experimental data. Experiments were conducted in a reservoir in which strong vortices were formed over an intake. Measurements of the flow field were carried out with an Acoustic Doppler Velocimeter (ADV) for a constant intake submerged depth and two different intake Froude numbers. The agreement between numerical and experimental results for 3D velocity field was good. Finally, using the validated numerical results, the flow behavior in the reservoir was analyzed. A funnel shape flow pattern was recognized in the reservoir toward the intake and its boundaries were identified. Another flow pattern observed was a spiral vortex motion from the water surface towards the intake. The present paper intends to make a deep understanding of flow field in a reservoir due to water withdrawal.

Section: Introductionmentioning

confidence: 99%

Numerical Simulation and Analysis of Flow In A Reservoir In The Presence of Vortex

Engineering Applications of Computational Fluid Mechanics

Zarrati

Jabbari

et al. 2014

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“…Recently, Möller et al (2012) reviewed the quantification of air entrained by intake vortices. It is also clear that free surface vortex formation is strongly influenced by the reservoir geometry (Ansar and Nakato, 2001;Sarkardeh et al, 2012). Literature is also available on vortex prevention, which mainly focuses on using various anti-vortex walls (Amiri et al, 2011;Anwar et al, 1978;Chen et al, 2004;Denny and Young, 1957;Johnson, 1972;Knauss, 1987).…”

Section: Introductionmentioning

confidence: 99%

Velocity field in a reservoir in the presence of an air-core vortex

Proceedings of the Institution of Civil Engineers - Water Manag

Jabbari

Zarrati

et al. 2014

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The velocity field in a reservoir in the presence of surface vortices was experimentally studied. Experiments were performed with a horizontal intake and with a constant submerged depth and two different intake Froude numbers.The spline smoothing method was used to improve the graphical presentation of the measured data. Results are presented and compared in different horizontal sections in the reservoir. A downward conical flow over the intake axis and an upward one below the intake axis were observed in the reservoir. Finally, the prevailing domains of vertical and horizontal velocities were determined.

“…Strength of surface vortices is significantly influenced by the reservoir geometry (Sarkardeh et al 2012). The correct identification of the flow pattern, and a quantification of the velocities characterizing the reservoir condition, eddies and recirculation zones, is important for engineering applications as well as design of an anti-vortex structure.…”

Section: Introductionmentioning

confidence: 99%

Vortices in dam reservoir: A case study of Karun III dam

Azarpira

Tavakkol

et al. 2014

Sadhana

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The present study focuses on the effect of vortex formation on plane velocities in a reservoir. Velocity measurements are performed in the hydraulic model of Karun III dam and hydropower plant. Different vortices were produced at the horizontal intake by changing the submerged depth. Tangential velocities were measured on a rectangular mesh in the reservoir. The results were then processed to plot the contour lines of the plane velocities and study the effect of vortex formation on the flow condition in the reservoir. Contour lines in different submerged depths show that circulation zones are formed in different potential locations over the intakes causing vortex formation. These results were correlated with the location of the appearing vortices observed in the experiments. Experimental data of this study could be useful for numerical modelling of vortex in the reservoirs.