Scale effects on the formation of vortices at intake structures

Gürbüzdal, Ferhat Aral
In the present study, possible scale effects on the formation of air-entraining vortices at horizontal intakes are studied experimentally. Basic dimensionless parameters that govern the onset of vortices at a horizontal intake in a model and a prototype are stated by dimensional analysis. Series of experiments are conducted on four intake pipes of different diameters located in a large reservoir. The relationship of critical submergence ratio with other dimensionless parameters is considered for a given Froude number and it is found out that the critical submergence ratio is affected by model length scale ratio and its natural result of side-wall clearance ratio and Reynolds number differences between model and prototypes. It is observed that, side-wall clearance ratio is not effective on the critical submergence ratio after it exceeds about 6. In addition to this, Reynolds number limit, beyond which viscous forces do not affect the vortex flow, is found out to be increasing with the increase in Froude number. An empirical relationship, which gives the critical submergence ratio as a function of Froude number, side-wall clearance ratio and Reynolds number is obtained by using data collected in the experiments.


Comparative study on sediment transport equations for delta formations in reservoirs
Pulcuoğlu, Başar; Tiğrek, Şahnaz; Department of Civil Engineering (2009)
In this study, a qualitative and comparative investigation on sediment transport equations used in prediction of rserevoir sedimentation is presented. 32 sediment transport equations, which are selected by literature review on sand and gravel size ranges, grouped according to the median particle sizes on which their derivation based. In order to compare these equations computer program DELTA, which is a one dimensional simulation program developed by Graf and Altınakar (1998) for the prediction of delta for...
Forced hydraulic jump on artificially roughened beds
Şimşek, Çağdaş; Tokyay, Nuray; Department of Civil Engineering (2006)
In the scope of the study, prismatic roughness elements with different longitudinal spacing and arrangements have been tested in a rectangular flume in order to reveal their effects on fundamental characteristics of a hydraulic jump. Two basic roughness types with altering arrangements have been tested. Roughness elements of the first type extends through the channel width against the flow with varying length and pitch ratios for different arrangements. The second type is of staggered essence and produced b...
Effect of hydraulic parameters on the formation of vortices at intake structures
Baykara, Ali; Göğüş, Mustafa; Köken, Mete; Department of Civil Engineering (2013)
The aim of this experimental study was to investigate the hydraulic conditions at which air-entraining vortices would form in front of horizontal intakes and to determine the ways of eliminating the formation of these vortices by testing anti-vortex devices. For these reasons, a series of experiments were conducted in an experimental setup composed of a reservoir having the dimensions of 3.10 m x 3.10 m x 2.20 m and a pump connected to the intake pipe. Within the reservoir, between the concrete side walls a...
Measurements of velocity profiles by using particle image velocimeter
Kemalli, Onur; Tiğrek, Şahnaz; Department of Civil Engineering (2009)
Particle Image Velocimetry (PIV) is an optical technique used to display and evaluate the motion of fine particles in a flow. In this experimental study, velocity profiles are examined by PIV system and basic analysis methods are compared.
Formation of air-entraining vortices at horizontal water intakes /
Zaloğlu, Cihan; Göğüş, Mustafa; Department of Civil Engineering (2014)
The goal of this study is to estimate the critical submergence depths of horizontal water intakes that have symmetrical and asymmetrical approach flow conditions by using empirical equations. Therefore a series of experiments were performed in a reservoir-pipe system dominated by gravity and controlled by a valve. On account of adjustable lateral walls, symmetrical and asymmetrical flow conditions were created at various Froude numbers. For a wide range of discharges and for three different pipe diameters, ...
Citation Formats
F. A. Gürbüzdal, “Scale effects on the formation of vortices at intake structures,” M.S. - Master of Science, Middle East Technical University, 2009.