USE OF ADV IN FLOW MEASUREMENT AND SIGNAL POST-PROCESSING IN A PART OF HIRAKUD COMMAND AREA

ADV measurements can be applied to find the average velocities and to find the velocity profiles. Acoustic Doppler Velocimeters (ADV) is used widely for the measurements of the three dimensional turbulent velocities. A new development of ADV, MicroADV from SonTek, is applied to measure the flow in free hydraulic jumps. The effects of presence of the air bubbles and boundary on the measurements of Micro ADV are taken into consideration. It was observed that the error of mean velocity measured by MicroADV is increased linearly with the air concentration at very low concentration. The effect of the boundary on the measurements of MicroADV starts when the distance from the measurement point to the boundary is less than about 3 cm. The relative error of MicroADV measurements found to be increased when the distance reduces. The acoustic Doppler velocimeter (ADV) is applied to record the instantaneous velocity components at a single-point with relatively high frequency. Here, in the present study, two ADV instruments i.e. Flow Tracker ADV, MicroADV are analyzed. The aim of the present work is to obtain the efficiency and limitations of ADV instruments in Hirakud dam command area which consists of three distributaries namely Chournpur Minor Canaland Mundoghat Minor Canal. The Flow Tracker ADV, velocity data at various sections of a canal can be obtained and simultaneously, the correspondence discharge was also calculated. MicroADV applied to record real time velocity data in X-axis (along the length), Y-axis (along the width) and Z-axis (along the depth). A software package named Horizon ADV can be applied to find the data using Micro ADV. The time series graphs of velocity, SNR and Correlation Score can be plotted for the analysis. The results indicated that acoustic Doppler velocimetry data cannot be applied without adopting suitable postprocessing. To obtain the post-processing of ADV data, Win ADV software was used, after that data was compared with the raw velocity data, and a conclusion was reached that ADV data shouldn't be used without post-processing because the ADV data are biased with disturbances like signal aliasing, spiking, navigation disturbances.