CFD Analysis of Helicoidal-Ramp Type Drop Shaft to Deal With High Head Drop Works in Manholes

The Helicoidal-Ramp Type Drop Shaft (DRS) efficiently attenuates dissipated energy by creating a spiral flow in the helicoidal ramp. The DRS prevents scouring of manholes while reducing the quantity of entrained air.A study of DRS was carried out by Tamura et al. (2010) based on verification through a hydraulic model experiment. However, in the present study, the mechanism of the exhaust and air entrainment of the drop shaft have not been researched in detail. Therefore, here, the direction and flow rate of air and water were investigated by visualizing the flow of air and water in the drop-shaft using Computational Fluid Dynamics (CFD). This study was used to confirm whether the flow of the fluid inside the drop shaft was as designed.