Study of flow hydraulic in the middle embayment using a numerical model

The area of an embayment and its characteristics, which are located along a river, are the most important factor for the maintenance of different species of Flora and fauna. To study the hydraulic characteristics of the flow in the embayment, a three-dimensional simulation model is needed to detect the exact location of the size and shape of the vortices. In this study, the data obtained from experiments, performed at Shahroud University of Technology, have been used (2019 - 2020). Measurements were performed on a continuous and homogeneous cavity flow with free surface in a square embayment with dimensions of 0.3 * 0.3 cm in 4 discharges (0.017, 0.024, 0.028, 033 / 0 cubic meters per second). Gyre formation observed in the embayment. In order to identify and analyze the flow pattern, numerical modeling was performed using physical model data and Flow3D numerical model. The RNG turbulence model, which was more consistent with the actual data, was selected and used by calibration. The flow pattern in the bay area showed that the created rotational cycle is a circular gyre. The speed at the entrance to the square embayment has a downward trend to half, and after reaching the zero point in the middle of the embayment, it finds an upward trend again. The longitudinal velocity, which is greater than the transverse and deep velocities, is also symmetrical in the embayment. Also, the transverse velocity has a negative direction in the first half of the embayment and a positive direction in the last half, which indicates the counter-clockwise movement of the gyre.