Hydraulic experiments in physical of a vortex drop shaft of the general drainage plan of Lisbon

Experimental campaign in a physical model of the vortex drop shaft of the Av. Almirante Reis of the General Drainage Plan of Lisbon for the analysis of the flow.

The physical model was constructed in the Hydraulic Structures Pavilion of LNEC in a reduced scale 1:11,57. The model included the main components, namely, the approach flow channel, the intake structure or vortex drop, the stilling chamber with the aeration system and the downstream pipe.

• The main objective is the characterization of the flow in vortex drop shafts and the prediction of the conveyance capacity.

The results are analyzed in a qualitative and quantitative ways. An insufficient discharge capacity was observed for a flow associated to a 100 years return period.