Author(s): Gaetano Crispino; Pasquale Contestabile; Diego Vicinanza; Corrado Gisonni
Linked Author(s): Gaetano Crispino, Diego Vicinanza, Corrado Gisonni
Keywords: Drop manholes; Energy dissipation; Energy loss; Hydraulic structure; Urban drainage system
Abstract: In the present literature review paper several experimental investigations on physical and numerical models of drop manholes and vortex drop shafts were considered. The examination of the experimental data led to the definition of a simple empirical equation, initially suggested for one type of drop manhole, to estimate the total head loss coefficient for both drop manholes and vortex drop shafts. The energy efficiency values, as detected by the corresponding physical and numerical tests, of all the drop structure models were also compared. The energy efficiency of vortex drop shafts is larger than in drop manholes, and it reaches easily the 90%. Drop manholes are, instead, characterized by a smaller energy efficiency, which was shown to increase as the drop height augments.