Discharge measurement using current-meter and analysis of velocity distribution in the water channel : master’s thesis

Abstract

Brzina toka vode u protjecajnim profilima vodotoka može se mjeriti hidrometrijskim krilom kojim se određuje brzina vodotoka s obzirom na broj okretaja propelera u jedinici vremena koji je uronjen u vodu. Na temelju izmjerene brzine vodotoka u više točaka protjecajnog profila, izračunava se ukupni protok. Hrvatski zavod za norme izdao je tri normativna dokumenta iz područja hidrologije u skladu s međunarodnom organizacijom za norme (ISO). Tim dokumentima su opisani dijelovi instrumenta, metode mjerenja brzina, načini kalibriranja, uvjeti korištenja instrumenta i način prikazivanja i obrade podataka. Propisanim metodama izmjerene su brzine a zatim grafičkim i aritmetičkim metodama određen protok, te analiza prostorne razdiobe brzina tečenja potoka Lomnica u naselju Lukavec na dva hidrološka profila.Commonly used instrument in order to determine the velocity of fluid is current-meter witch is immersed in water and the number of revolutions of the rotor measured with current-meter during a specified time interval is used for computation of discharge. Water flow velocity measured in multiple location in cross-sectional area are used for discharge computation. Croatian Standards Institute issued three normative documents in accordance with the International Organization for Standardization (ISO). These documents specifies the operational requirements, construction, calibration, and maintenance of rotating-element devices for the measurement of flow velocities and methods for determining the velocity. Using prescriptive methods water flow velocities are determined, and then for computation of discharge are used arithmetical and graphical methods. Analysis of spatial water flow velocity distribution in two hydrological cross-section areas has been made on Lomnica stream in Lukavec