Determining the layered flow velocity in the Latyan reservoir using acoustic tomography technology

Acoustic tomography technology is an advanced method of remote sensing, which has been used and verified by many researchers in recent years to measure flow velocity and temperature in different water environments. The purpose of this research is the feasibility of using this technology in reservoirs of dams to measure the flow velocity in different layers. The basis of this method is to calculate and record the travel time of acoustic rays in the water environment, including the reservoir of the dam. In the first step, the propagation of sound rays from the first station to the second station was simulated. Then, according to the propagated rays and the obtained travel times and solving the inverse problem with the regularization method, the average flow velocity, and layered flow velocity were calculated. In this research, two acoustic stations with mutual transmission with a frequency of 10 kHz were placed in the reservoir of Latian Dam on October 23, 2020. Five layers with a distance of ten meters in depth were selected. The results of solving the adjusted inverse problem showed that the maximum velocity of 0.0006m/s occurs in the first layer (0 to 10 m depth). For the flow velocity of layers, two to five, 0.0003, 0.0001, 0.0002, 0.0001 m/s were calculated respectively, which according to the close to zero flow velocity of the dam reservoir at the time of data collection, the velocity of the flow was obtained with a relatively good approximation. It is suggested that in future studies, data collection should be done when the water discharge valves are open so that the results can be compared with the results of this research.