An open channel flume with a central 180-degree bend with a rigid bed is designed to obtain a better understanding of the complex flow pattern around a T-shaped spur dike located in a sharp bend. The 3-dimensional velocities are measured by using an acoustic Doppler velocimetry under clear-water conditions. This study's primary objective is to compare variations of the mean flow pattern along a 180-degree bend with a variety of T-shaped spur dike lengths. In order to do so, parameters such as streamlines, the maximum velocity distribution, and the secondary flow strength under the influence of three T-shaped spur dike lengths will be analyzed and then compared with the case where no spur dikes are implemented. The results show that with the spur dike placed at the bend apex, the mean secondary flow strength at that range increases by approximately 2.5 times. In addition, a 67% increase in the length of the wing and web of the spur dike leads to a 27% growth in the mean secondary flow strength along the bend.
This study investigates the possibilities of the generation of synthetic flood waves and their utilization for the solution of the transformed run-off from reservoirs during different hydrological situations. The synthetic flood waves were derived by means of a useful combination of the generator of the synthetic rainfall in a short-time interval with the rainfall-runoff model. The sets of the flood waves with requisite properties /e.g. the N-year flood peak, the volume of the N-year flood wave, etc./ were selected from the long synthetic time series. The aim of the study was to elaborate the hitherto existing methods of the run-off control based only on one design hydrograph and to evaluate the favourable operations in other situations. and Studie zkoumá možnosti generování syntetických povodňových vln a jejich využití pro řešení transformace odtoku z nádrží v různých hydrologických situacích. Syntetické povodňové vlny byly odvozeny účelným propojením generátoru syntetických srážkových úhrnů v krátkých časových intervalech se srážkoodtokovým modelem. Z dlouhých nagenerových řad byly vybírány soubory povodňových vln s požadovanými vlastnostmi (např. N-letými kulminacemi, objemy a j.). Cílem výzkumu bylo prohloubit dosavadní metodické postupy řešení operativního řízení odtoku založené jen na podkladě jedné návrhové povodně a posoudit nejvhodnější manipulace i v jiných situacích.