WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

Browse

Filters

20153

Settings

Has files: NoPublisher: search.filters.publisher.International Association for Hydro-Environment Engineering Research

Search Results

Now showing 1 - 3 of 3
  • Conference Object
    Experimental Investigation of Flow Characteristics of Discretized Triangular Hydrographs
    (International Association for Hydro-Environment Engineering Research, 2015) Pulat, Aytaç; Ata, Cem; Altınsoy, Sinem; Bombar, Gökçen; Elçi, Şebnem
    In this study effect of discretization of triangular hydrographs on flow characteristics is investigated. All experimental tests are carried out in a rectangular flume of 70 cm width and 18 m length and having a slope of 0.004. The flow rate is measured by an electromagnetic flow meter mounted on the inlet pipe and the time variation of flow depth is monitored at various locations. The point velocities are measured by a side-looking ultrasonic velocity meter at 17 different elevations along the water column by repeating the same hydrograph 17 times in unsteady flows, so that the velocity time series could be obtained at each location. A pump speed control unit (PSCU) is used to generate the hydrograph. The results of a three step discretized hydrograph and a continuous triangular shaped hydrograph generated in the flume are compared. Rising and falling periods of both hydrographs are 5.5 minutes and the base and peak flow rates are 14 l/s and 62 l/s respectively. The time varying mean of velocity time series in both stream-wise and vertical directions are investigated. The velocity profiles as well as the turbulence characteristics are compared with the ones obtained from the triangular hydrograph and the discretized hydrograph at unsteady flow conditions. The effect of discretization of the triangular hydrograph on flow velocities and turbulence characteristics is also discussed.
  • Conference Object
    Reverse Flood Routing in Rivers
    (International Association for Hydro-Environment Engineering Research, 2015) Tayfur, Gökmen; Moramarco, Tommaso
    This study developed model to do riverse flood routing in natural channels. The developed model has basically four components: (1) it expresses an inflow hydrograph by a Pearson Type-III distribution, involving parameters of peak discharge, time to peak, and a shape factor; (2) it employs the basic continutiy equation for flow routing, (3) it relates the storage to downstream flow stage and channel characterictis; and (4) it relates the lateral flow to downstream flow discharge with coefficients. The parameters, coefficients and exponents of the models were obtained using the genetic algorithm method. The developed models are applied to generate upstream hydrographs, using just downstream station information for Ponte Nuovo and Monte Molino river reach of 30.8 km distance within the same basin where the wave travel time is 3h and drainage area is about 1135 km(2). Inflow hydrographs were generated and compared against the observed ones. The model simulation of inflow hydrographs were satisfactory.
  • Conference Object
    An Approach for Estimating Seetling Velocity in Turbulent Flows
    (International Association for Hydro-Environment Engineering Research, 2015) Elçi, Şebnem
    Precise estimation of the settling velocity of particles in turbulent flows is required for many engineering applications including modeling of the transport of suspended sediments and the transport of particle pollutants. This study attempts to quantify the turbulence from direct measurements at a reservoir and presents an approach for estimation of settling velocities of suspended sediments modified by the quantified turbulence. A novel application of acoustic Doppler instruments for measurement of settling velocities was presented considering the fact that settling velocity of particles are commonly estimated indirectly from the balance of settling and diffusive gradients. In the present study, synchronized 3-D velocity and temperature time series were monitored at Tahtali Reservoir in Turkey where the data were utilized to characterize the turbulence characteristics by various means (i.e. buoyancy flux, Richardson flux and Stokes number) provided in the literature. Stokes' settling velocities modified by the turbulent characteristics were compared with the measured settling velocities to discuss which parameters have the greatest impact on the settling mechanism and need to be considered in the presented approach. The results of the study revealed that, when production of turbulence was high, modified settling velocities matched the monitored velocities better. So; it was concluded that modification of Stokes' settling velocities by turbulent kinetic energy production profiles performs better for high turbulent conditions.