Hydraulic Model Test of the Bottom Outlet of Sivand Dam
This paper presents the results of hydraulic test of bottom outlet of the Sivand Dam. The aims of the hydraulic model test are, gate discharge characteristics and gate loading. Results for different gate openings are also compared with calculated values obtained by a finite element method. Key-Words: Hydraulic model test, Dam, Finite element method, Gate, Gate Discharge
Investigation on cavitation occurrence potential in Seymareh dam’s bottom outlet
ABSTRACT Cavitation phenomenon is one of the common problems of bottom outlets which convey high-speed flows. In the present study, the possibility of cavitation occurrence is numerically investigated. A numerical model is developed for the flow passing through bottom outlet using FLOW 3D software and K-ε (RNG) turbulent model. The model is operated for reservoir normal and maximum water heads also for various service gate openings. For normal head and different service gate openings, the research results show that cavitation indices are lower than the critical amount (0.2) on the conduit bed for 10%, 20%, 30%, 40%, 50%, 70%, and 80% service gate openings. Also, the side walls of conduit encounter with cavitation phenomenon immediately downstream of service gate for all gate openings. It is observed that the conduit top wall is free of cavitation damage hazard where the minimum cavitation index is equal to 0.46. At maximum reservoir head, the cavitation is not occurred inside the emergency gate slot and on its walls.
Instability of Elastically Suspended Tainter-Gate System Caused by Surface Waves on the Reservoir of a Dam
In reference [38] also, there is evidence that this relationship held for \x, but not X„, in the range 3.8 X 10* < Re < 9.0 X 10*. I t was suggested that this is due to anisotropy in the dissipating motions, associated with an appreciable contribution to turbulent shear stress, at these low Reynolds numbers. In support of this contention, more recent inspection (reference [47]) of the latest data for u'/uT has indicated that true invariance does not set in until Re > 10, because there are still significant contributions to the turbulence energy from viscosity influenced scales of motion at lower Reynolds numbers. However, at sufficiently high Reynolds number, say Re > 10, the results of the simple analysis above will apply and