ABSTRACT
Vortex drops consist of three main elements: inlet structure, vertical drop shaft, and outlet structure. The approach flow from a straight, nearly horizontal channel is transformed into rotational flow by the inlet structure. The flow down the drop shaft is helicoidal. The vortex shaft is a type of hydraulic structure for which a generalised design is available. The inlet structure transforms the approach flow from a straight, normally rectangular and nearly horizontal channel into a helicoidal flow. The shape of the inlet structure can be circular, spiral, screw or tangential. The central air core stabilizes the water flow along the wall of a vortex shaft. The air-water mixture running down the drop shaft is received by the outlet structure. Its purposes are to direct the nearly vertical annular jet to the horizontal tailwater conduit, to deaerate the air-water mixture, and to safely dissipate the remaining energy.
