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EN
The lagoon is a natural system protected from the sea by a dune barrier creating energy from the movement of rising and falling tides, thus providing a sustainable option for extracting energy from tidal currents. The energy that can be extracted is one of the most potential renewable energy sources. Therefore, the interaction of tidal currents with stratification layers has become important to optimize the efficiency of energy conversion at each depth layer in water masses. We have chosen as a case study, the Oualidia lagoon (Atlantic coast of Morocco). This ecosystem is characterized by hydrodynamics relatively favored by tides and tidal currents which are the main intra-lagoon currents, with a predominance of the semi-diurnal component M2 (period of 12 h 25) with 2.1 to 3.4 m of tidal range. The Multicell Argonaut-XR ADCP is used to measure the current velocity in the Oualidia lagoon at three different stations to study tidal patterns in a vertical layer of water depth. At each station, current velocities were recorded in each 0.5 m layer over a depth of about 5 m. As a result, this study showed that current velocity measurements to be used as renewable energy are found at station 1 located at a depth of 3.5 meters (~layer 5) with a current velocity of 0.771 m/s and a power density value of 235.344 W/m2, station 2 located at a depth of 3.5 meters (~layer 5) with a current velocity of 0.4 m/s and a power density value of 32.86 W/m2 and station 3 is located at a depth of 3 meters (~layer 6) with a current velocity of 0.527 m/s and a power density value of 75.157 W/m2. The variation in current velocities between the different stations is mainly influenced by tides (Flood/ebb), the period of the measurements and the location of the stations. This work presents a model for extracting electrical energy through the use of tidal and current flow variations in such semi-enclosed natural system including lagoons.
EN
Reliable, rapid and non-invasive techniques are important for the monitoring of the ecosystem of the semi-enclosed Black Sea, especially sensitive to the human impact. Hydroacoustic techniques meet these requirements. In the study, the ADCP data (volume backscattering strength and water velocities), collected in the north-east part of the Black Sea in October 2014, were used to understand some biotic and abiotic processes in the environment. The study was motivated by the fact that the used ADCP mounted on the autonomous (moving vertically) platform provided measurements with significantly higher spatial resolution that it was in the previous hydroacoustical studies of Black Sea ecosystem. The main objective of the analysis was to determine the velocity of zooplankton diel vertical migration and understand the processes responsible for the variability of the volume backscattering strength.
PL
Istotą wykonywania pomiarów hydrometrycznych w korytach rzecznych jest wyznaczenie wartości prędkości oraz strumienia objętości przepływu wody dla danego napełnienia. Współcześnie coraz szersze zastosowanie znajdują urządzenia akustyczne wykorzystujące efekt Dopplera. W korytach rzecznych i jeziorach już od lat 90. największe zainteresowanie skupiają akustyczne przepływomierze profilujące ADCP (Acoustic Doppler Current Profilers). W niniejszej pracy zostały przedstawione podstawy teoretyczne pomiarów hydrometrycznych oraz przykładowe wyniki badań IMGW-PIB Oddział we Wrocławiu, który w ramach państwowej służby hydrologiczno-meteorologicznej zobowiązany jest do prowadzenia przedmiotowych pomiarów. Z uwagi na różnorodny sprzęt pomiarowy jakim dysponuje IMGW-PIB zaprezentowano zestawienie klasycznego pomiaru młynkiem hydrometrycznym z współcześnie stosowanymi urządzeniami akustycznymi, dla różnego rodzaju cieków.
EN
The primary goal of hydrometrie measurements in river channels is to record the water velocity and water level (depth) at a specific flow rate. Nowadays, more frequent use of acoustic devices exploiting the Doppler effect is made both for land surface and oceanographic waters. From the 90s a significant progress has been made on acoustic flow profiling, termed ADCP (Acoustic Doppler Current Profiler), currently widely used in hydrometry. IMGW-PIB (Institute of Meteorology and Water Management - National Research Institute) is also implementing these instruments into the regular hydrometrie service. In the paper both the theoretical background of the ADCP and sample records are presented and discussed. Also a reference is made to the results obtained by classic propeller instruments for a variety of field conditions. Concluding, despite of some limitations in use and in tracking water velocity, the ADCP’s offer new possibilities and deliver new (quantity and quality) value to the hydrometry and hydrology.
EN
During the 2010 flood in the Odra basin a measuring campaign was executed that produced a set of data on peak discharges. Flow measurements located near gauging stations were taken from a boat with an Acoustic Doppler Current Profiler (ADCP) equipped with a GPS. The paper presents a detailed analysis of the records, including referencing to ortophotomaps, to assess the quality of ADCP recording, local flow characteristics and finally to re-evaluate the total discharge values. Further, the flow is divided between the main channel and the floodplains, while the main channel in the case of the presence of groynes is additionally divided into a central zone between the groynes and zones of groynes. Partitioning of particular zones to the total discharge is calculated along with average and maximum local flow velocities. The study delivers data for the development of more reliable numerical modelling tools, which in turn may fulfil the measuring gaps in situ. It is shown that the modern field data acquisition GIS post processing, and numerical modelling support each other and improve the final overall result, bringing hydrologic products to a higher standard. The synergy of hydraulics and geoinformatics in hydrology is therefore highly recommendable.
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