Kinematic characteristics of the flow of an intake structure with a curvilinear threshold

1.	An intake structure with a closed flow having a vertical axis of rotation contributes to the development of a favorable kinematic structure in the channel, which makes it possible to minimize scouring beyond the structure.
2.	Excedence of the near-bottom average and maximum velocities above the average velocities in the channel comes about atl3.3hc downstream from the axis of the intake.
3.	The magnitude of the ratio of the maximum 1st-percentile and average 50th-percentile flow velocities (v1%/v50%), which characterizes the velocity pulsation, attains values for the undisturbed flow in the near-bottom region at a distancel4.1hc.
4.	Complete equalization of the plan diagram of velocities is noted at a distance (4.9–7.8)hc from the axis of the intake structure.

Translated from Gidrotechnicheskoe Stroitel'stvo, No. 4, pp. 17–19, April, 1991.