Friday 3 july 2015
8:30 - 8:45h at Asia (level 0)
Themes: (T) Water engineering, (ST) Experimental facilities and instrumentation, (ST) River and coastal engineering
Parallel session: 14C. Engineering - Industrial
Stepped spillways are hydraulic structures for energy dissipation that have regained significant interest for researchers and dam engineers in the last two decades. By the increase of the use of stepped spillways continually, the researchers have been concentrating on the increasing efficiency of this kind of spillways and due to this fact, several methods have been presented. In this regard, the finding of the optimal dimensions of the steps according to the passing flow regime can be mentioned. This study presented the experimental results and characteristics of energy dissipation on different types of stepped chutes at skimming flow regime. All experiments were conducted in a prismatic rectangular flume of width 0.28 m, depth 0.35m and length 10 m. The centrifugal pump lies beside the flume at upstream, and it is having a rate capacity of (60 l/s) was used to deliver flow to the flume. At the end of the flume, moveable gate is installed to regulate the tail water depth of hydraulic jump. A water gage with 0.01 accuracy was used to measure the depth of flow after jump. Five configurations on different types of steps were using in the experimental laboratory which are inclined at physical model with ratio height to length of step (h/l= 0.8391) and (h=3cm) at skimming flow regime. The results showed that the relative energy dissipation is increased in all configurations than the relative energy dissipation in conventional steps. The results showedthat the using of different types of steps have the most influence on the amount of energy losses, they are increased the energy losses by about (2%-20%) at different runs and configurations in comparison of horizontal steps.