Linked pools culverts facilities
Аннотация
Abstract A mathematical model is presented, a hydraulic jump that appears during the transition of the flow from a turbulent state ( Fr>1.0 ) to critical ( Fr<1.0 ). The main assumptions made to obtain the divergent form of the Saint-Venant hydrodynamic equations are given: - planned (two-dimensional) effects do not affect the flow (but still local energy losses due to sharp turns and changes in the channel shape in the plan can be taken into account; to take into account such losses in local sections of the channel increased local hydraulic resistance is introduced). The results of numerical studies of the downstream of the culvert structure of the medium-pressure reservoir are presented. The developed numerical model using explicit difference schemes is presented. Based on the results of numerical studies of the hydraulic jump, the possibility of establishing the degree of quenching of the excess flow energy having the destructive ability of the construction of the downstream of medium-pressure reservoirs is substantiated. The calculation results showed that an increase in the hydraulic resistance value promotes the displacement of the hydraulic jump against the current and an increase in its associated depths. At the concatenation site of the upstream, there was a sharp decrease in the Froude number from 2.76 to 0.69, with a change in average speed from 8.81 m/s to 3.26 m/s. It is substantiated that from the calculated values of the vertical dimensions of the hydraulic jump with various values of hydraulic resistance and the throughput of the structure, it is possible to determine the horizontal dimensions of the jump, which makes it possible to select the optimal sizes of the downstream attachment zone in and after the hydraulic jump.