Ústav vodních staveb

Browse

Now showing 1 - 5 of 43

Determination of the yield of thermal mineral springs emerging into the Bečva River in the Teplice Spa
(Sciendo, 2025-01-13) Julínek, Tomáš; Říha, Jaromír; Grešl, Milan; Holešovský, Jan; Cabalka, Matouš
The mineral water in the Teplice Spa emerges into the Bečva River bed from the hypogenic karst formed by Palaeozoic limestones. Recently the focus on the hydrological and hydrogeological conditions of the mineral springs issues from the planning of the Skalička Dam whose reservoir is believed to be interconnected with the karstic formation and may influence the regime of mineral waters in the spa. One of the related particular problems is to determine the discharge of the mineral water which emerges into the Bečva River in the river reach along the Teplice Spa. The knowledge about the emerging mineral water discharge is crucial for further assessment of an impact of planned reservoir. The most challenging issue and novelty of the study was to determine a relatively small increment of the discharge in the Bečva river, when the magnitude of the error of determination was comparable to the determined discharge. Therefore, for the assessment of the discharge three methods were applied, namely measurements by the classical current meter, measurements using the Acoustic Doppler Current Profiler and evaluation of the measurements of electrical conductivity along the river reach. The analysis of obtained results and comparison of the obtained methods indicate the emerging discharge between 250 and 500 l/s with realistic value about 350 l/s. The study shows quite good agreement of results determined by individual methods which justifies the methodology used and is good guidance for similar studies.
Free flow over a partially contracted thin-plate weir with a triangular notch ofangle 20.23° and zero weir height
(Sciendo, 2025-06-01) Pospíšilík, Šimon; Kotaška, Stanislav; Duchan, David; Zachoval, Zbyněk; Orfánus, Martin; Šoltész, Andrej; Gruchot, Andrzej Tadeusz; Zydroń, Tymoteusz
The paper explores flow characteristics in the case of free flow of clean water over a partially contracted thin-plate weir with a triangular notch of angle 20.23° and with zero weir height above the bottom of the approach channel ofrectangular cross-section at 5 approach channel widths and 7 heads. The description was based on the results from experimental research and numerical simulations. The numerical simulations allowed the description of the characteristics in parts of the flow where measurements were difficult to perform. The experimental research quantifies the validity of the numerical simulations and establish recommendations for construction of numerical models. The boundary between a partially contracted weir and a fully contracted weir was established by dimensionless approach channel width of the value 0.32, the flow characteristics (water surface, velocity) in the full range of the partially contracted weir (dimensionless approach channel width in range 0.32 BU* 1.00), and recommendations for the placement of a cross-section to measure water surface level for determine the heads (dimensionless distance 4 x* 2) were verified.
Design of Web GIS Application for Planning of Military River Crossing
(Univerzita obrany Brno, 2024-11-07) Dohnal, Filip; Straka, Šimon; Duchan, David
Successful ground military operations necessitate thorough comprehension of the operational environment, particularly terrain and water features. This article advocates for the utilization of Geographic Information System (GIS) technology to develop a dynamic web application aimed at analyzing and planning watercourse crossings. By harnessing the capabilities of ArcGIS Pro and ArcGIS Online, the proposed application integrates hydrological and terrain data to provide comprehensive insights into the feasibility of crossing specific water obstacles under varying conditions. Key considerations include terrain characteristics, river channel profiles, and the tactical specifications of military vehicles. While the application is currently in the conceptual phase and awaits verification, its potential in enhancing operational planning for the Czech Armed Forces is underscored. This GIS-based approach promises to enhance decision-making processes by offering real-time, interactive support for evaluating and strategizing water obstacle crossings within military operations.
The application of a minimum specific energy concept for a fish ladder design
(Polish Academy of Sciences, 2022-05-13) Kubrak, Michal; Smolinski, Blažej; Říha, Jaromír; Kodura, Apoloniusz; Popielski, Pawel; Jablonski, Kamil
Structural solutions in terms of fish ladders and the use of natural materials to construct them often raise concerns regarding the possibility of using the standard calculation methods. The fish ladder being designed on the Wisłok river consists of three pools, separated from each other by baffles made of rock boulders. The purpose of this study was to analyze water surface profiles for fish ladder at specific values of flow rates. The paper presents the results of hydraulic calculations under the conditions of constant flow rate based on the concept of a minimum specific energy. According to this method, water flow through boulders is critical. Thus, it does not take into account head losses, which are hard to estimate and which are the integral part of typical calculation methods, e.g. the use of equations to determine the flow rate of a weir. An additional advantage of this method is that there is no need to assume the flow pattern of one specific weir. Verification calculations of the water depths were conducted using the HEC–RAS software, under an assumption of an one-dimensional steady water flow. Water depths in the fish ladder, calculated using both methods, were similar, despite the adopted different calculation concepts, and can be used in ichthyologic analyses.
Analysis of Seepage in a Laboratory Scaled Model using Passive Optical Fiber Distributed Temperature Sensor
(MDPI, 2020-01-29) Ghafoori, Yaser; Maček, Matej; Vidmar, Andrej; Říha, Jaromír; Kryžanowski, Andrej
Abstract: Seepage is the key factor in the safety of dikes and earthfill dams. It is crucial to identify and localize the seepage excesses at the early stages before it initiates the internal erosion process in the structure. A proper seepage monitoring system should ensure a continuous and wide area seepage measurement. Here, continuous monitoring of seepage at the laboratoryscale is achieved by a passive optical fiber Distributed Temperature Sensing (DTS) system. An experimental model was designed which consists of initially unsaturated sand model, water supply, seepage outflow, optical fiber DTS system, and water and air temperature measurement. Initially, the sand temperature was higher than the temperature of the seepage water. An optical fiber DTS system was employed with a hightemperature resolution, short sampling intervals and short time intervals for temperature monitoring in the sand model. In the system, the small variation in the temperature due to groundwater flow was detected. The numerical analysis was conducted for both the seepage process and the heat transfer progression in the sand model. The results of the heat flow simulation were evaluated and compared with the measured temperature by the optical fiber DTS. Obvious temperature reduction was obtained due to seepage propagation in the sand. The rate of temperature reduction was observed to be dependent on the seepage flow velocity.

Browse

Recent Submissions