Study on the Hydraulic Characteristics of Flood Discharge from a Large Flow Spillway with Extra LongOverflow Width
The Nyerere project adopts the layout of low weir head,ultra overflow width and large discharge spillway.In or-der to accurately understand its actual flood discharge capacity,downstream energy dissipation,anti-scour and confluence hydraulic characteristics,the flow coefficient,energy dissipation rate,water flow back to the channel,river velocity and so on under different schemes were studied by combining model test and numerical simulation.The results are as follows.The actual flow capacity of the originally designed spillway with low head and high weir meets the design requirements,and the effect of scaling effect can be avoided by using numerical simulation method.The energy dissipation method with the step height of 1.5 m is the best for the dam surface,and the lateral confluence inside the apron is relatively smooth.The incom-ing flow from both sides collides with energy in the apron and enters the downstream main channel.The average water depth of the main channel behind the dam has increased by nearly 30％,and the average velocity has decreased by about 20％.
extra long overflow width spillwaylow head over weirflow coefficientenergy dissipationlateral confluence
万方数据
维普
