Application of ADV Method for Measurement of Flow Velocity Components in the Malina Stream

Abstract

In this article, the results of velocity profile measurements in a stream by using the ADV method (Acoustic Doppler Velocimet ry) are presented. The measurements are carried out in the Malina stream (Záhorie lowland). The velocity profile was measured with using the three - dimensional ultrasound probe of ADV device - FlowTracker (SonTek/YSI). The obstacle, represented with 120 - liters barrel, was installed into the stream and by this way the velocity profile was modified. First, the undisturbed veloci ty profile was measured and subsequently there was measured the modification of this velocity profile caused by the obstacle installatio n. Velocities were measured in the proposed grid of points; the same grid was used for both cases (without the obstacle, with th e obstacle). The grid was created by verticals along the cross - section profile and by several value of depth in each vertical. The vertical lines were proposed in distance 1,25; 1,50; 1,75; 2,00; 2,25; 2,50; 2,75; 3,00; 3,25; 3,50; 3,75 and 4,00 m from th e right bank of the stream. Depth of points in each vertical were 0,15; 0,30; 0,45 m from the water level of the stream. The result s of the measurement is a database of vx, vy, vz components in the grid points, from which it is possible to determine the velocity p rofiles of individual components or resultant of these three components of the point velocity. The measurement results confirmed the suitability and applicability of the ADV method represented by FlowTracker 3D to determine the distribution of point velocity components in the cross - section profile. This method, as one of the few ones, allows obtaining the values of the velocity components at any point of flow directly in the field conditions.