In skimming flows on stepped spillway, flow resistance is predominantly a form drag process. Cavity recirculation and air entrainment are intense. The interactions between entrained air bubbles and mixing layers may cause some reduction in flow resistance. The paper presents new evidence showing a reduction in friction factor in skimming flow with increasing free-surface aeration. The experimen...

Many permanent spillway tunnels of high earth-rock dams are rebuilt from their diversion tunnels. Scour problem is focused because of their high water head and velocity. Energy Approach is a new method to Estimating Scour and is used here to estimate the depth of scour downstream of 1 spillway tunnel of Zipingpu Project. The method is illustrated working fine by comparing its results with data ...

This paper presents a classification of cavitation damage levels on spillway surface. Two important factors influencing cavitation damage have been considered in this study, flow velocity and cavitation index. Based on these factors, five different damage levels from no cavitation damage to major cavitation damage have been determined. The method was applied to data of the Shahid Abbaspour dam ...

Inadequate spillway capacity is one of the major reasons for dam failure in embankment dams. New Swedish guidelines for the design flood, adopted in 1990, have led to an extensive work with upgrading of the discharge capacity in a number of dams. A large number of dams have such a spillway design that they do not easily allow for accurate theoretical calculations of the discharge capacity due t...

Many of the quality recreational fishing opportunities in Illinois occur in reservoirs. Fish emigration from reservoirs during periods of overflow is termed “dam” or “spillway escapement.” Escapement can detract from recreational fishing opportunities in the reservoir and can disturb downstream ecosystems by creating an influx of unwanted and/or non-native fish. Previous research on spillway es...

The sky-jump spillway is an economical solution to return water rivers, but unsuitable flip bucket design might jeopardize the spillway, dam, or other appurtenant works. Characterizing in advance, during phase, position, size, and shape of erosion basin would be useful ensure that flow returned river a safe way. Also, it for safety assessment throughout exploitation phase when has not yet reach...

dam spillways are the structures that lead rightly and safely the outflow downstream, so that the dam integrity can be guaranteed. many accidents with dams have been caused by an inadequate spillway design or insufficient capacity. to accurately respond the hydraulic spillways, designers use physical modeling for designing this kind of structures. the scale effect in the spillway modeling, as a...

Dam spillways are the structures that lead rightly and safely the outflow downstream, so that the dam integrity can be guaranteed. Many accidents with dams have been caused by an inadequate spillway design or insufficient capacity. To accurately respond the hydraulic spillways, designers use physical modeling for designing this kind of structures. The scale effect in the spillway modeling, as a...