阶梯-深潭消能率的模拟研究

Numercial simulation on the energy dissipation of step-pool system

以山区河流天然的阶梯-深潭系统为研究对象,进行了不同流量情况下的阶梯-深潭消能率的对照模拟研究.实验表明,阶梯-深潭水流经过阶梯段跃起,紧接着跌入下游的深潭段,在深潭段水流的紊动扩散、翻腾旋滚和碰撞剪切作用下,水流速度急剧减小,控制了河床持续下切;实测天然小流量情形下的阶梯-深潭消能率可以高达95%以上,数值模拟大流量情形消能率也均高于80%,充分的耗散了水流能量,对河床、岸坡的稳定起到了显著的保护作用.

This paper studies the natural step-pool system in mountainous rivers.It makes numerical simulation analysis,achieving the mechanism and variation laws of step-pool system＇s energy dissipation rate under different flow rate.The experiments show that the flow rate reducce rapidly under the action of turbulent diffusion,spins the troubled rolling and collision shear in the deep pools section.In addition,the numercial simulation experiments indicate that the energy dissipation of step-pool system can be as high as 95% under the natural small flow conditions.Moreover,the big flow condition also is up to 80%.It verifies that step-pool system can sufficiently dissipate the flow energy,effectively control the riverbed incising,and maintain the stability of watercourse and keep the riverbed in a healthy state.